Engine Controls/fuel - 2.4l - DTC p0411 (Luk) to DTC p2635 and Symptom Troubleshooting &amp; Diagnosis Buick Regal V

Description and Operation

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

Ignition ON
Verify that DTC P0412, P0418, P2430, P2431, P2432, P2433, P2440, or P2444 is not set. If any of the DTCs are set Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) If none of the DTCs are set.
Verify the scan tool BARO pressure parameter is within the range specified in the «Altitude Versus Barometric Pressure»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-specifications__altitude-versus-barometric-pressure) If not within the specified range Refer to «DTC P0106»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-dtc-p0010-to-dtc-p0411) If within the specified range
Verify the scan tool Secondary Air Injection Pressure Sensor and BARO pressure parameters are within 3 kPa (0.4 psi). If not within the specified range Refer to «DTC P2430-P2433 (LEA)»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-dtc-p0411-luk-to-dtc-p2635-and-symptom-troubleshooting-diagnosis) , «DTC P2430-P2433 (LAF, LUK)»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-dtc-p0411-luk-to-dtc-p2635-and-symptom-troubleshooting-diagnosis) If within the specified range
Verify the secondary air injection solenoid valve activates when commanding the Secondary Air Injection Solenoid Valve ON and OFF with a scan tool. If the secondary air injection solenoid valve does not operate as specified Refer to Circuit/System Testing-Secondary Air Injection Solenoid Valve Malfunction If the secondary air injection solenoid valve operates as specified
Engine running
Verify the secondary air injection pump turns ON and OFF when commanding the Secondary Air Injection Pump Relay ON and OFF with a scan tool. If the secondary air injection pump does not operate as specified Refer to Circuit/System Testing-Secondary Air Injection Pump Malfunction If the secondary air injection pump operates as specified
Verify the scan tool Secondary Air Injection Pressure Sensor parameter increases between 15-22 kPa (2.2-3.2 psi), over the current reading, when the Secondary Air Injection Pump Relay is commanded ON with a scan tool. If not within the specified range Refer to Circuit/System Testing-Secondary Air Injection System Pressure Not In Range. If within the specified range
Verify the scan tool Secondary Air Injection Pressure Sensor parameter increases between 8-15 kPa (1.2-2.2 psi), over the current reading, when the Secondary Air Injection System is commanded ON with a scan tool. If not within the specified range Refer to Circuit/System Testing-Secondary Air Injection System Pressure Not In Range. If within the specified range
Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
Verify the DTC does not set. If the DTC sets Refer to Circuit/System Verification-step 1 If the DTC does not set
All OK

Circuit/System Testing

Secondary Air Injection Solenoid Valve Malfunction

Ignition OFF, disconnect the KR26 secondary air injection solenoid valve relay.
Verify a test lamp illuminates between the B+ circuit terminal 30 and ground. If the test lamp does not illuminate and the circuit fuse is good Test for less than 2 ohms in the B+ circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, verify the fuse is not open and there is voltage at the fuse. If the test lamp does not illuminate and the circuit fuse is open Ignition OFF Test for infinite resistance between the B+ circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Disconnect the harness connector at the Q29 secondary air injection solenoid valve. Test for infinite resistance between the control circuit terminal 5 and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test or replace the Q29 secondary air injection solenoid valve. If the test lamp illuminates
Disconnect the harness connector at the Q29 secondary air injection solenoid valve.
Ignition OFF and all vehicle systems OFF, it may take up to 2 minutes for all vehicle systems to power down. Test for less than 10 ohms between the Q29 secondary air injection solenoid valve ground circuit terminal 4 and ground. If 10 ohms or greater Ignition OFF. Test for less than 2 ohms in the ground circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, repair the open/high resistance in the ground connection. If less than 10 ohms
Connect the harness connector at the Q29 secondary air injection solenoid valve.
Connect a 15 A fused jumper wire between the B+ circuit terminal 30 and the control circuit terminal 87.
Verify the Q29 secondary air injection solenoid valve is activated. If the Q29 secondary air injection solenoid valve does not activate Ignition OFF, disconnect the harness connector at the Q29 secondary air injection solenoid valve. Test for less than 2 ohms in the control circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, test or replace the Q29 secondary air injection solenoid valve. If the Q29 secondary air injection solenoid valve activates
Test or replace the KR26 secondary air injection solenoid valve relay.

Secondary Air Injection Pump Malfunction

Ignition OFF, disconnect the KR25 secondary air injection pump relay.
Verify a test lamp illuminates between the B+ circuit terminal 87 and ground. If the test lamp does not illuminate and the circuit fuse is good Ignition OFF Test for less than 2 ohms in the B+ circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, verify the fuse is not open and there is voltage at the fuse. If the test lamp does not illuminate and the circuit fuse is open Ignition OFF Test for infinite resistance between the B+ circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Disconnect the harness connector at the G21 secondary air injection pump. NOTE: The secondary air injection pump circuit is provided with a flyback diode that may cause the DTC to set if internally shorted. Connect a DMM, set on the diode setting, between the control circuit terminal A and ground. Verify the DMM reading is between 0.5-0.8 V and displays O.L. when the DMM leads are reversed. If less than the specified range, repair the short to ground on the circuit. If within the specified range Test or replace the G21 secondary air injection pump. If the test lamp illuminates
Disconnect the harness connector at the G21 secondary air injection pump.
Ignition OFF and all vehicle systems OFF, it may take up to 2 minutes for all vehicle systems to power down. Test for less than 10 ohms between the G21 secondary air injection pump ground circuit terminal B and ground. If 10 ohms or greater Ignition OFF. Test for less than 2 ohms in the ground circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, repair the open/high resistance in the ground connection. If less than 10 ohms
Connect the harness connector at the G21 secondary air injection pump.
Connect a 50 A fused jumper wire between the B+ circuit terminal 87 and the control circuit terminal 30.
Verify the G21 secondary air injection pump is activated. If the G21 secondary air injection pump does not activate Ignition OFF, disconnect the harness connector at the G21 secondary air injection pump. Test for less than 2 ohms in the control circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, Test or replace the G21 secondary air injection pump. If the G21 secondary air injection pump activates
Test or replace the KR25 secondary air injection pump relay.

Secondary Air Injection System Pressure Not In Range

Verify the following conditions do not exist: Hoses/pipes restricted or blocked Hoses/pipes disconnected Plugged secondary air injection pressure sensor port Damaged secondary air injection check valve If a condition is located Repair or replace the affected component as necessary. If all components test normal
If a condition is not located, and the secondary air injection pump operates with no pressure change, replace the G21 secondary air injection pump.

Component Testing

Relay Test

Ignition OFF, disconnect the appropriate relay.
Test for the following resistance between terminals 85-86. 50-75 ohms-KR25 secondary air injection pump relay 70-110 ohms-KR26 secondary air injection solenoid valve relay If not within the specified range Replace the relay. If within the specified range
Test for infinite resistance between the terminals listed below: 30 and 86 30 and 87 30 and 85 85 and 87 If less than infinite resistance Replace the relay. If infinite resistance
Install a 15 A fused jumper wire between relay terminal 85 and 12 V. Install a jumper wire between relay terminal 86 and ground.
Test for less than 2 ohms between terminals 30 and 87. If 2 ohms or greater Replace the relay. If less than 2 ohms
All OK

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

«Relay Replacement (Within an Electrical Center)»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-repair-instructions) , «Relay Replacement (Attached to Wire Harness)»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-repair-instructions)
«Secondary Air Injection Pipe Replacement»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions)
«Secondary Air Injection Pump Inlet Hose Replacement»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions)
«Secondary Air Injection Check Valve Replacement»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions)
«Secondary Air Injection Pump Replacement»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions)

Perform the «Diagnostic System Check - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Diagnostic Fault Information

Circuit	Short to Ground	Open/High Resistance	Short to Voltage
Secondary Air Injection Pump Relay Coil Ignition Supply	P0412, P0418	P0418	P0690
Secondary Air Injection Pump Relay Coil Control	P0418	P0418	P0690, P2431
Secondary Air Injection Solenoid Valve Relay Coil Ignition Supply	P0412	P0412	P0690
Secondary Air Injection Solenoid Valve Relay Coil Control	P0412	P0412	P0412, P0690

The secondary air injection system aids in the reduction of hydrocarbon emissions during a cold start. The electric air pump forces fresh air into the exhaust stream in order to accelerate the catalyst operation. Ignition voltage is supplied directly to the secondary air injection pump relay and secondary air injection solenoid valve relay. The Engine Control Module (ECM) controls the relays by grounding the control circuit with a solid state device called a driver. The ECM monitors the control circuits for open, short to ground or short to a voltage condition.

The ignition voltage is between 10-32 V.
The DTCs run continuously once the above conditions are met.

DTC P0412 or P0418

The ECM detects that the commanded state of the driver and the actual state of the control circuit do not match for greater than 5 s.

DTC P0412 and P0418 are Type B DTCs.

Conditions for Clearing the DTC

DTC P0412 and P0418 are Type B DTCs.

If the condition is intermittent, move the related harnesses and connectors, with the engine operating, while monitoring the circuit status for the component with a scan tool. The circuit status parameter changes from OK or Not Run to Malfunction if there is a condition with the circuit or a connection.

Schematic Reference

Engine Controls Schematics (LEA) , Engine Controls Schematics (LUK)

Connector End View Reference

Description and Operation

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Ignition ON, command the Secondary Air Injection Solenoid Valve Open and Closed with a scan tool. You should hear and feel a click from the relay and the Secondary Air Injection Solenoid Valve in response to the commands. Repeat as necessary to verify that the Air Solenoid Valve and relay are operating.
Command the Secondary Air Injection Pump Relay ON and OFF with a scan tool. You should hear and feel a click from the relay and the Secondary Air Injection Pump should turn ON and OFF in response to the commands.
Command the appropriate relay or component ON and OFF or Open and Closed with a scan tool while observing the control circuit status parameters. Each parameter should display OK or Not Run.
Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Ignition OFF, remove the appropriate relay.
Ignition ON, verify that a test lamp illuminates between the relay coil B+ circuit terminal 86 and ground. If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance. If the circuit tests normal and the ignition circuit fuse is open, test all components connected to the ignition circuit and replace as necessary.
Verify a test lamp does not illuminate between the relay control circuit terminal 85 and B+. If the test lamp illuminates, test the control circuit for a short to ground. If the circuit tests normal, replace the K20 ECM.
Test for less than 1 V between the relay coil control circuit terminal 85 and ground. If greater than the specified range, test the control circuit for a short to voltage. If the circuit tests normal, replace the K20 ECM.
Connect a DMM set to the diode setting between the control circuit terminal 85 and ground.
Command the relay or component ON and OFF or Open and Closed with a scan tool. The DMM should transition from 2.5-3.5 V when commanded OFF or Closed to less than 1 V when commanded ON or Open. If the circuit voltage does not correspond to the specified values, test the control circuit for an open/high resistance. If the circuit tests normal, replace the K20 ECM.
If all circuits test normal, test or replace the relay.

Ignition OFF, disconnect the appropriate relay.
Test for the following resistance between terminals 85 and 86: 50-75 ohms-Secondary Air Injection Pump Relay 70-110 ohms-Secondary Air Injection Solenoid Valve Relay If the resistance is not within the specified range, replace the relay.
Test for infinite resistance between the following terminals: 86 and 87 86 and 30 85 and 87 87 and 30 If not the specified value, replace the relay.
Install a 15 A fused jumper wire between relay terminal 86 and B+. Install a jumper wire between relay terminal 85 and ground. Test for less than 2 ohms between terminals 87 and 30. If greater than the specified range, replace the relay.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

«Relay Replacement (Within an Electrical Center)»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-repair-instructions) , «Relay Replacement (Attached to Wire Harness)»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-repair-instructions)
«Control Module References»(/buick/regal/v-2009-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for Engine Control Module replacement, setup, and programming

Perform the «Diagnostic System Check - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

A 3-way catalytic converter controls emissions of hydrocarbons, CO and NOx. The catalyst within the converter promotes a chemical reaction, which oxidizes the hydrocarbons and the CO that are present in the exhaust gas. This process converts the hydrocarbons and the CO into water vapor and CO2, and reduces the NOx, by converting the NOx into nitrogen. The catalytic converter also stores oxygen. The ECM monitors this process by using a Heated Oxygen Sensor (HO2S) that is in the exhaust stream after the 3-way catalytic converter. The HO2S 2 produces an output signal that the ECM uses to calculate the oxygen storage capacity of the catalyst. This indicates the ability of the catalyst to convert the exhaust emissions efficiently. The ECM monitors the efficiency of the catalyst by allowing the catalyst to heat, then wait for a stabilization period while the engine is idling. The ECM then adds and removes fuel while monitoring the HO2S 2. When the catalyst is functioning properly, the HO2S 2 response to the extra fuel is slow compared to the response of the HO2S 1, which is located before the 3-way catalytic converter. When the HO2S 2 response is near that of the HO2S 1, the oxygen storage capability and efficiency of the catalyst may be degraded below an acceptable threshold.

DTC P0010, P0011, P0013, P0014, P0016, P0017, P0030, P0036, P0101, P0102, P0103, P0112, P0113, P0116, P0117, P0118, P0121, P0122, P0123, P0128, P0131, P0132, P0133, P0134, P0135, P0137, P0138, P013A, P013B, P013C, P013E, P013F, P0140, P0141, P0171, P0172, P0220, P0223, P0300, P0301-P0304, P0443, P0449, P0455, P0496, P0506, P0507, P1101, P1133, P2100, P2102, P2103, P2122, P2123, P2127, P2128, P2135, P2138, P219A, P2232, P2235, P2270, or P2271 is not set.
Before the ECM performs the idle test, the vehicle must be driven under the following conditions: The engine speed is greater than 915 RPM The engine run time is greater than a calibrated value Both conditions exist for greater than 15 s
The throttle is in the rest position.
The intake air temperature (IAT) is between -20 to +250°C (-4 to +482°F).
The ignition voltage is greater than 11 V.
The engine coolant temperature (ECT) is between 40-127°C (104-261°F).
The barometric pressure (BARO) is greater than 70 kPa.
The engine has been idling less than 50 s.
The vehicle speed is less than 2 km/h (1 mph).
The short term fuel trim is learned.
The air flow into the engine is between 3-13 g/s.
The EVAP purge concentration is learned.
The catalytic converter calculated temperature is between 450-950°C (842-1, 742°F).
The engine is operating in Closed Loop.
The transmission is not in P/N (automatic transmission only).

This diagnostic attempts one test during each valid idle period once the above conditions have been met. This diagnostic attempts up to 8 tests during each drive cycle.

The ECM determines that the efficiency of the catalyst has degraded below a calibrated threshold.

DTC P0420 is a Type A DTC.

Inspect for the following conditions, which may cause a catalytic converter to degrade

An engine misfire
High engine oil or high coolant consumption
Retarded spark timing
A weak or poor spark
A lean fuel mixture
A rich fuel mixture
A damaged oxygen sensor or wiring harness

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Observe the DTC information with a scan tool. Verify there are no other DTCs set. If a DTC is set, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) for further diagnosis.
Operate the vehicle within the Conditions for Running the DTC. Observe the scan tool Catalyst Monitor Not At Idle Test Conditions Met parameter. The parameter will change to Yes when the Conditions have been met. If not the specified value, operate the vehicle within the Off Idle Conditions.
When the parameter has changed to Yes and the conditions are safe, stop and idle the vehicle in gear.
Apply the service brake.
Monitor the scan tool Catalyst Monitor Test State parameter. When the parameter indicates Active, the Catalyst Monitor Test is running.
Continue to monitor the parameter. When the parameter indicates Inactive, the Catalyst Monitor Test has completed.
When the test has completed, the Catalyst Monitor Test Counter parameter will increment by one and the Catalyst Monitor Test Result parameter will indicate Pass, Fail or No Decision. If no decision has been made, repeat steps 2-6 until the Test Result parameter indicates Pass or Fail.

Verify the following conditions do not exist with the catalytic converter: Dents A severe discoloration caused by excessive temperatures Road damage An internal rattle caused by damaged catalyst substrate Restrictions If a condition is found, replace the catalytic converter.
Verify the following conditions do not exist with the exhaust system: Leaks Physical damage Loose or missing hardware If a condition is found, repair the exhaust system.
Verify the following conditions do not exist with the B52B Heated Oxygen Sensor 2. The HO2S is not at the correct torque Damage If a condition is found, repair or replace the B52B Heated Oxygen Sensor 2 as necessary.
If all physical conditions test normal, test or replace the catalytic converter.

Note. A new converter with less than 161 kilometers (100 miles) on it may set DTC P0420 due to out-gassing of the internal matting. Operating the vehicle at highway speeds for approximately 1 h may correct the condition.

«Exhaust Leakage»(/buick/regal/v-2009-2013/remont/exhaust/#engine-exhaust-system__exhaust-leakage)
«Restricted Exhaust»(/buick/regal/v-2009-2013/remont/exhaust/#engine-exhaust-system)
«Heated Oxygen Sensor Replacement - Sensor 2»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions)
«Catalytic Converter Replacement (L4)»(/buick/regal/v-2009-2013/remont/exhaust/#engine-exhaust-system) , «Catalytic Converter Replacement (LDK or LHU)»(/buick/regal/v-2009-2013/remont/exhaust/#engine-exhaust-system)

Repair Verification

Install any components that have been removed or replaced during diagnosis.
Perform any adjustments, programming or setup procedures that are required when a component is removed or replaced.
Clear the DTCs with a scan tool.
Vehicle OFF for 60 s.
Operate the vehicle within the Conditions for Running the DTC. Observe the scan tool Catalyst Monitor Not At Idle Test Conditions Met parameter. The parameter will change to Yes when the Conditions have been met. If not the specified value, operate the vehicle within the Off Idle Conditions.
When the parameter has changed to Yes and the conditions are safe, stop and idle the vehicle in gear.
Apply the service brake.
Monitor the scan tool Catalyst Monitor Test State parameter. When the parameter indicates Active, the Catalyst Monitor Test is running.
Continue to monitor the parameter. When the parameter indicates Inactive, the Catalyst Monitor Test has completed.
When the test has completed, the Catalyst Monitor Test Counter parameter will increment by one and the Catalyst Monitor Test Result parameter will indicate Pass, Fail or No Decision. If no decision has been made, repeat steps 5-9 until the Test Result parameter indicates Pass or Fail.
If the repair was related to a DTC, duplicate the Conditions for Running the DTC and use the Freeze Frame/Failure Records, if applicable, in order to verify the DTC does not reset. If the DTC resets or another DTC is present, refer to the «Diagnostic Trouble Code (DTC) List - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) for further diagnosis.

Perform the «Diagnostic System Check - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The engine off natural vacuum (EONV) test is the small leak detection diagnostic for the evaporative emission system. This diagnostic tests the Evaporative Emission (EVAP) system for a small leak when the key is turned OFF and the correct conditions are met. Heat from the exhaust system is transferred into the fuel tank while the vehicle is operating. When the vehicle is turned OFF and the EVAP system is sealed a change in the fuel tank vapor temperature occurs which results in a corresponding pressure change in the fuel tank vapor space. This change is monitored by the engine control module (ECM) using the fuel tank pressure sensor input. With a leak in the system, the amount of pressure change will be less than that of a sealed system.

Note. The following conditions must be met prior to ignition OFF.

DTCs P0112, P0113, P0116, P0117, P0118, P0120, P0125, P0128, P0443, P0446, P0449, P0452, P0453, P0463, P0503, P1106, P1107, P1111, P1112, P1114, P1115, P1516, P2101, P2108, P2120, P2125, P2129, P2138, P2610 are not set.
The diagnostic runs once after a cold start drive cycle.
The start-up intake air temperature (IAT) is between 4-30°C (39-86°F).
The start-up engine coolant temperature (ECT) is less than 30°C (86°F).
The start-up IAT and ECT are within 8°C (46°F).
The barometric pressure (BARO) is greater than 70 kPa.
The ambient air temperature is between 2-32°C (36-90°F).
The engine run time minimum is 10 minutes.
The vehicle has traveled greater than 5 kilometers (3 miles) this trip.
The ECT is greater than 70°C (158°F).
The fuel level is between 10-90 percent.
The ignition is OFF.
A refueling event is not detected.
DTC P0442 runs once per drive cycle during the hot soak period after the ignition is turned OFF and may require up to 40 minutes to complete. The controller will not make more than 2 test attempts per day. The time since the last completed EONV test must be at least 17 hours.

The ECM detects a pressure change that is less than a calibrated amount.
The ECM must complete several EONV tests before the diagnostic can turn the MIL ON or OFF.

DTC P0442 is a Type A DTC.

The EVAP system can be filled with smoke more quickly and completely by opening the system opposite the end where the smoke is injected. When injecting smoke at the service port, remove the fuel fill cap, or temporarily leave the vent open, until smoke is observed, then close the system and continue testing. If using a fuel cap adapter at the filler neck, use the J 41413-VLV EVAP service port vent tool at the service port to allow the system to fill faster.
To help locate intermittent leaks using the GE-41413-A Evaporative emissions system tester (EEST), move all EVAP components while observing smoke with the GE-41413-SPT high intensity white light.
Individual components can be isolated and tested using adapters in the GE-41413-300 EVAP cap and plug kit.
A condition may exist where a leak in the EVAP system only exists under a vacuum condition. This type of leak may be detected by using the scan tool Purge/Seal function to create a vacuum in the EVAP system and then observe the FTP parameter for vacuum decay.

Schematic Reference

Engine Controls Schematics (LEA) , Engine Controls Schematics (LUK)

Connector End View Reference

Description and Operation

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Special Tools

CH-48096 EVAP Service Access Port Tool
GE-41413-A Evaporative Emissions System Tester (EEST)
GE-41413-300 EVAP Cap and Plug Kit
GE-41413-SPT High Intensity White Light
J 41413-VLV EVAP Service Port Vent Tool

For equivalent regional tools, refer to Special Tools (Diagnostic Tools) .

Note. Refer to the GE-41413-A Evaporative emissions system tester (EEST) operation manual for detailed instructions in Evaporative Emission System Diagnosis . Larger volume fuel tanks and/or those with lower fuel levels may require several minutes for the floating indicator to stabilize. Ensure that the underbody temperature of the vehicle and the tester are similar.

Disconnect the purge tube at the quick connector on the EVAP canister side of the purge solenoid valve and install the CH-48096 EVAP service access port tool. Connect the GE-41413-A Evaporative emissions system tester (EEST) to the vehicle at the EVAP service port adapter.
Using a scan tool, close the EVAP vent solenoid valve to seal the EVAP system.
Use the flow meter on the GE-41413-A Evaporative emissions system tester (EEST), calibrated to 0.51 mm (0.020 in) to determine that there is no leak in the EVAP system. If a leak is detected, use the GE-41413-A Evaporative emissions system tester (EEST) to apply smoke to the EVAP system at the service port or the purge tube until the leak is located using the GE-41413-SPT high intensity white light.

Seal the EVAP system and use the flow meter on the GE-41413-A Evaporative emissions system tester (EEST), calibrated to 0.51 mm (0.020 in) to determine that there is no leak in the EVAP system.
Clear the DTCs.

Perform the «Diagnostic System Check - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Circuit	Short to Ground	High Resistance	Open	Short to Voltage
Ignition 1 Voltage - Purge Supply	P0443	P0443	P0443
Battery Positive - Vent Supply	P0449	P0449	P0449
Evaporative Emission (EVAP) Purge Solenoid Control	P0443	P0443	P0443	P0443
Evaporative Emission (EVAP) Vent Solenoid Control	P0449	P0449	P0449	P0449

An ignition voltage is supplied directly to the evaporative emission (EVAP) purge solenoid valve. The engine control module (ECM) grounds the EVAP purge solenoid valve control circuit through an internal switch called a driver. The ECM monitors the status of the driver. The EVAP purge solenoid valve is pulse width modulated (PWM). A scan tool will display the amount of ON time as a percentage.

Battery voltage is supplied to the EVAP vent solenoid valve. The ECM grounds the EVAP vent solenoid valve control circuit through an internal switch called a driver. The ECM monitors the status of the driver. A scan tool will display the commanded state of the EVAP vent solenoid valve as ON or OFF.

The ignition is ON.
The system voltage is greater than 11 V.
DTCs P0443 and P0449 run continuously when the above conditions are met.

The ECM detects that the commanded state of the driver and the actual state of the control circuit do not match for a minimum of 0.25 seconds.

DTCs P0443 and P0449 are Type B DTCs.

Schematic Reference

Engine Controls Schematics (LEA) , Engine Controls Schematics (LUK)

Connector End View Reference

Description and Operation

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

P0443

Ignition ON, engine OFF, you should hear a clicking sound when the EVAP purge solenoid valve is commanded to 50 % with a scan tool. The clicking sound should stop when the EVAP purge solenoid valve is commanded to 0 %. The rate at which the valve cycles should increase when the commanded state is increased, and decrease when the commanded state is decreased.
Operate the vehicle within the conditions for running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the freeze frame/failure records data.

P0449

Ignition ON, engine OFF, command the EVAP vent solenoid valve to Not Venting and Venting with a scan tool. Listen for a click when the valve operates.
Verify that both the Venting and the Not Venting states are commanded with a scan tool while observing their parameter status. EVAP Vent Solenoid Circuit Short To Ground Test Status EVAP Vent Solenoid Circuit Open Test Status EVAP Vent Solenoid Circuit Short To Voltage Test Status Their parameter status should display OK or Not Run
Operate the vehicle within the conditions for running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the freeze frame/failure records data.

Ignition OFF, disconnect the harness connector at, Q 12 evaporative emission purge solenoid valve for P0443 Q 13 evaporative emission vent solenoid valve for P0449
Ignition ON, verify that a test lamp illuminates between the voltage supply circuit terminal and ground. If the test lamp does not illuminate, test the voltage supply circuit for a short to ground or an open/high resistance. If the circuit tests normal and the voltage supply circuit fuse is open, test or replace the, EVAP purge solenoid valve for P0443 EVAP vent solenoid valve for P0449
Connect a test lamp between the voltage supply circuit terminal and the control circuit terminal.
With a scan tool command the, EVAP purge solenoid valve to 50 % EVAP vent solenoid valve to Venting and Not Venting The test lamp should respond to the command. If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the K20 ECM. If the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the K20 ECM.
If all circuits test normal, replace the appropriate solenoid valve.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

«Evaporative Emission Canister Purge Solenoid Valve Replacement»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions)
«Evaporative Emission Canister Vent Solenoid Valve Replacement»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions)
«Control Module References»(/buick/regal/v-2009-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, setup, and programming

Perform the «Diagnostic System Check - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
Ignition Voltage	P0443, P0458	P0443
EVAP Canister Purge Valve Control Circuit	P0458	P0443	P0459

The evaporative emission (EVAP) canister purge valve is used to purge fuel vapor from the EVAP canister to the intake manifold. The EVAP canister purge valve is pulse width modulated (PWM). Ignition voltage is supplied directly to the EVAP canister purge valve. The engine control module (ECM) controls the solenoid by grounding the control circuit with a solid state device called a driver. The driver is equipped with a feedback circuit that is pulled-up to a voltage. The ECM can determine if the control circuit is open, shorted to ground, or shorted to a voltage by monitoring the feedback voltage.

The engine speed is greater than 80 RPM.
The ignition voltage is between 10-18 volts.
The ECM has commanded the EVAP canister purge valve ON and OFF at least once during the ignition cycle.
The DTCs run continuously once the above conditions are met.

P0443

The ECM detects the EVAP canister purge solenoid control circuit is open. The condition exists for 4 seconds or a cumulative of 30 seconds.

P0458

The ECM detects the EVAP canister purge solenoid control circuit is shorted to ground. The condition exists for 4 seconds or a cumulative of 30 seconds.

P0459

The ECM detects the EVAP canister purge solenoid control circuit is shorted to voltage. The condition exists for 4 seconds or a cumulative of 30 seconds.

DTCs P0443, P0458 and P0459 are Type B DTCs.

If the condition is intermittent, move the related harnesses and connectors, with the engine operating, while monitoring the scan tool EVAP Purge Solenoid Circuit Test Status parameters for the component. A circuit test status parameter changes from OK or Not Run to Fault if there is a condition with the circuit or a connection.

Schematic Reference

Engine Controls Schematics (LEA) , Engine Controls Schematics (LUK)

Connector End View Reference

Description and Operation

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Ignition ON, command the EVAP purge solenoid valve to 50 % with a scan tool. You should hear an audible click.
Engine operating, observe the scan tool EVAP Purge Solenoid Circuit Test Status parameters. Verify the parameters display OK or Not Run.
Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Ignition OFF, disconnect the harness connector at the Q12 EVAP purge solenoid Valve.
Ignition ON, verify that a test lamp illuminates between the ignition voltage circuit terminal 1 and ground. If the test lamp does not illuminate, test the ignition voltage circuit for a short to ground or an open/high resistance. If the circuit tests normal and the ignition voltage circuit fuse is open, test all components connected to the ignition voltage circuit and replace as necessary.
Connect a test lamp between the control circuit terminal 2 and the ignition voltage circuit terminal 1.
Command the EVAP purge solenoid valve to 50 % and then to 0 % with a scan tool. The test lamp should illuminate or flash and then go OFF. If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the K20 ECM. If the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the K20 ECM.
Test for 2.6-4.6 V between the control circuit terminal 2 and the K20 ECM housing. If the voltage is not within the specified range, replace the K20 ECM.
If all circuits test normal, test or replace the Q12 EVAP purge solenoid.

Ignition OFF, disconnect the harness connector at the Q12 EVAP purge solenoid valve. Test for 15-20 ohms between the terminals of the Q12 EVAP purge solenoid valve. If not within the specified range, replace the Q12 EVAP purge solenoid valve.
Measure the resistance between each terminal of the Q12 EVAP purge solenoid valve and the EVAP purge solenoid valve housing. The DMM should display OL. If less than the specified value, replace the Q12 EVAP purge solenoid.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

«Evaporative Emission Canister Purge Solenoid Valve Replacement»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions)
«Control Module References»(/buick/regal/v-2009-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, setup, and programming

Perform the «Diagnostic System Check - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

This DTC tests the evaporative emission (EVAP) system for a restricted or blocked EVAP vent path. The engine control module (ECM) commands the EVAP purge solenoid valve Open and the EVAP canister vent solenoid valve Closed. This allows vacuum to be applied to the EVAP system. Once a calibrated vacuum level has been reached, the ECM commands the EVAP canister purge solenoid valve Closed and the EVAP canister vent solenoid valve Open. The ECM monitors the fuel tank pressure (FTP) sensor for a decrease in vacuum. If the vacuum does not decrease to near 0 inch H2O in a calibrated time, this DTC sets.

Fuel Tank Pressure Sensor Signal Voltage	Fuel Tank Pressure
Less than 1.5 V	Positive Pressure
More than 1.5 V	Negative Pressure/Vacuum

DTCs P00C8, P00C9, P0068, P0106, P0107, P0108, P0111, P0112, P0113, P0114, P0116, P0117, P0118, P0122, P0123, P0125, P0128, P160E, P160D, P0191, P0192, P0193, P0222, P0223, P0443, P0449, P0452, P0453, P0454, P0502, P0503, P0606, P0722, P0723, P1106, P1107, P16F3, P1104, P2100, P2101, P2102, P2103, P2135, P2227, P2228, P2229, P2230 are not set.
The ignition voltage is between 11-32 V.
The barometric pressure (BARO) is greater than 70 kPa.
The fuel level is between 10-90 %.
The start-up engine coolant temperature (ECT) is less than 35°C (95°F).
The start-up intake air temperature (IAT) is between 4-30°C (39-86°F).
The start-up ECT and IAT are within 9°C (48°F) of each other.
DTC P0446 runs once per trip when the above conditions have been met.

The FTP sensor is more than -11 inches H2O vacuum for 2 s during the 13 minute test.

The FTP is less than -2.5 inches H2O or more than +5 inches H2O for 3 s after a cold start ignition ON.

DTC P0446 is a Type B DTC.

An intermittent condition could be caused by a damaged EVAP vent housing, a temporary blockage at the EVAP vent solenoid valve inlet, or a pinched vent hose. A blockage in the vent system may also cause a poor fuel fill problem.
An EVAP canister filter that is restricted can cause this DTC to set. Refer to «Evaporative Emission Canister Replacement»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions) .

Schematic Reference

Engine Controls Schematics (LEA) , Engine Controls Schematics (LUK)

Connector End View Reference

Description and Operation

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Ignition ON and fuel cap removed, verify that the FTP sensor parameter is between 1.3-1.7 V. If not within the specified range, go to the FTP sensor section in Circuit/System Testing.
Install the fuel cap.
With the engine running, the EVAP vent solenoid valve open, use a scan tool to command the EVAP purge solenoid valve to 100 %. The fuel tank vacuum should not increase to more than -15 mm Hg (-8 inches H2O). If the fuel tank vacuum is greater than the specified range, go to the restriction section in Circuit/System Testing.
Using the scan tool, decrease the canister purge duty cycle from 100 % to 0 %. The vacuum should decrease to near zero. If the fuel tank vacuum does not return to zero or appears to decrease too slowly go to the restriction section in Circuit/System Testing.
Operate the vehicle within the conditions for running the DTC. You may also operate the vehicle within the conditions that you observed from the freeze frame/failure records data.

Note. Perform the Circuit/System Verification before proceeding with the Circuit/System Testing.

Restriction

With the engine running, the EVAP vent solenoid valve open, and the EVAP purge solenoid valve commanded to 100 %, the fuel tank vacuum should not increase to more than -15 mm Hg (-8 inches H2O). If the fuel tank vacuum is greater than the specified value, isolate the restriction by disconnecting one component at a time while the EVAP canister purge solenoid valve is commanded to 100 % and the vent valve is open.
Using the scan tool, decrease the canister purge duty cycle from 100 % to 0 %. The vacuum should decrease to near zero. If the fuel tank vacuum does not return to zero, or appears to decrease too slowly, inspect the components in the EVAP vent system for a restriction.

Fuel Tank Pressure Sensor

Ignition OFF, disconnect the harness connector at the fuel tank pressure sensor.
Ignition OFF, test for less than 5 ohms between the low reference circuit terminal B and ground. If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the fuel tank pressure sensor.

«Fuel Tank Pressure Sensor Replacement (NU6)»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions) , «Fuel Tank Pressure Sensor Replacement (NT7)»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions)
«Evaporative Emission Canister Vent Solenoid Valve Replacement»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions)
«Evaporative Emission Canister Replacement»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions)
«Control Module References»(/buick/regal/v-2009-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, setup and programming

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

With the engine running, the EVAP canister vent solenoid valve open and the EVAP canister purge solenoid valve commanded to 100 percent, the fuel tank vacuum should not increase to more than -15 mm Hg (-8 inches H2O).

Perform the «Diagnostic System Check - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
Ignition Voltage	P0499	P0498
EVAP Canister Vent Solenoid Valve Control Circuit	P0498	P0449	P0499

The evaporative emission (EVAP) canister vent valve is used for EVAP system diagnostics. The EVAP canister vent valve is a normally open valve. Battery positive voltage is supplied directly to the EVAP canister vent valve. The engine control module (ECM) controls the solenoid by grounding the control circuit with a solid state device called a driver. The driver is equipped with a feedback circuit that is pulled-up to a voltage. The ECM can determine if the control circuit is open, shorted to ground, or shorted to a voltage by monitoring the feedback voltage. If the ECM detects the control circuit voltage is within a predetermined range when the circuit is commanded OFF, this DTC sets.

The engine speed is greater than 80 RPM.
The ignition voltage is between 10-18 volts.
The ECM has commanded the EVAP canister vent valve ON and OFF at least once during the ignition cycle.
The DTCs runs continuously once the above conditions are met.

P0449

The ECM detects the voltage on the EVAP canister vent valve control circuit is between 2.6-4.6 volts when the driver is commanded OFF. The condition exists for less than 4 seconds or for a cumulative of 30 seconds.

P0498

The ECM detects the voltage on the EVAP canister vent valve control circuit is less than 2.6 volts when the driver is commanded OFF. The condition is present for greater than 4 seconds or for a cumulative of 30 seconds.

P0499

The ECM detects the voltage on the EVAP canister vent valve control circuit is greater than 4.6 volts when the driver is commanded ON. The condition is present for greater than 4 seconds or for a cumulative of 30 seconds.

DTCs P0449, P0498 and P0499 are Type B DTCs.
The EVAP system will only purge during open loop.

DTCs P0449, P0498 and P0499 are Type B DTCs.

Schematic Reference

Engine Controls Schematics (LEA) , Engine Controls Schematics (LUK)

Connector End View Reference

Description and Operation

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Command the EVAP vent solenoid valve ON and OFF with the scan tool. An audible click should be heard when changing between the commanded states.
Start the engine, observe the scan tool EVAP Vent Solenoid Valve Circuit Test Status parameters. The circuit test status parameters should display OK or Not Run.
Engine Idling, observe the DTC information with a scan tool. DTC P0449, P0498, or P0499 should not set.
Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Ignition OFF, disconnect the Q13 EVAP vent solenoid valve harness connector.
Ignition ON, verify that a test lamp illuminates between the ignition voltage circuit terminal B and ground. If the test lamp does not illuminate, test the ignition voltage circuit for a short to ground or an open/high resistance. If the circuit tests normal and the ignition voltage circuit fuse is open, test all components connected to the ignition voltage circuit and replace as necessary.
Ignition OFF, connect a test lamp between the control circuit terminal A and the ignition voltage circuit terminal B.
Ignition ON, command the scan tool EVAP vent solenoid valve ON and OFF. The test lamp should turn ON and OFF. If the test lamp remains ON all the time, test the control circuit for a short to ground. If circuit/connections test normal, replace the K20 ECM. If the test lamp remains OFF all the time, test the control circuit for a short to voltage or an open/high resistance. If circuit/connections test normal, replace the K20 ECM.
Test for 2.6-4.6 V between the control circuit terminal 2 and ground. If not within the specified range, replace the K20 ECM.
If all circuits/connections test normal, test or replace the Q13 EVAP vent solenoid valve.

Ignition OFF, disconnect the Q13 EVAP vent solenoid valve harness connector.
Test for 20-24 ohms between the terminals of the Q13 EVAP vent solenoid valve. If not within the specified range, replace the Q13 EVAP vent solenoid valve.
Measure the resistance between each terminal of the Q13 EVAP vent solenoid valve and the Q13 EVAP vent solenoid valve housing. The DMM should display OL. If less than the specified value, replace the Q13 EVAP vent solenoid valve.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

«Evaporative Emission Canister Vent Solenoid Valve Replacement»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions)
«Control Module References»(/buick/regal/v-2009-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, setup, and programming

Perform the «Diagnostic System Check - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each of the diagnostic category.

Circuit	Short to Ground	High Resistance	Open	Short to Voltage	Signal Performance
FTP Sensor Low Reference		P0446, P0451	P0446		P0451
FTP Sensor Signal	P0452		P0452	P0453	P0451, P0454
FTP Sensor 5 V Reference	P0452, P0530, P0641	P0451	P0446, P0452	P0453, P0530, P0641

Typical Scan Tool Data

Circuit	Normal Range	Short to Ground	Open	Short to Voltage
Operating Conditions: With EVAP system vented to atmosphere
FTP Sensor Low Reference		1.5 V	4.6 V
FTP Sensor Signal	1.5 V	0 V	0 V	5 V
FTP Sensor 5 V Reference		0 V	0 V	5 V

FTP Sensor Voltage

The fuel tank pressure (FTP) sensor measures air pressure or vacuum in the evaporative emission (EVAP) system. The engine control module (ECM) supplies a 5 V reference and a low reference circuit to the FTP sensor. The FTP sensor signal voltage varies depending on EVAP system pressure or vacuum. The ECM also uses this FTP signal to determine atmospheric pressure for use in the engine-off small leak test, DTC P0442. Before using this signal as an atmospheric reference it must first be re-zeroed.

P0451

DTC P0451 runs only when the engine-off natural vacuum small leak test, P0442, executes.
The number of times this test runs can range from 0-2 per engine-off period. The length of the test can be up to 10 min.

P0452 and P0453

DTC P0452 and P0453 run continuously when the ignition is ON.

P0454

DTC P0454 runs only when the engine-off natural vacuum small leak test, P0442, executes.
This test can run once per engine-off period. The length of the test can be up to 10 min.
A refueling event is not detected.

P0451

This DTC will set if the controller is unable to re-zero the FTP sensor voltage within a calibrated range during the engine-off small leak test, P0442.

P0452

The FTP sensor voltage is less than 0.1 V for more than 5 s.

P0453

The FTP sensor voltage is more than 4.9 V for more than 5 s.

P0454

If, during the engine-off natural vacuum small leak test, P0442, the ECM detects an abrupt FTP signal change, other than a refueling event, this DTC will set. An abrupt change is defined as a change of 1 in H2O in the span of 1 s.

DTCs P0451 and P0454 are Type A DTCs.
DTCs P0452 and P0453 are Type B DTCs.

DTCs P0451 and P0454 are Type A DTCs.
DTCs P0452 and P0453 are Type B DTCs.

P0451 and P0454

A restriction in the EVAP canister or vent lines could prevent fuel vapor pressure from bleeding off fast enough. If the vent system cannot bleed off pressure fast enough, the re-zero procedure may not complete successfully, which could cause this code to set.
Ensure that the reference port on the FTP sensor is unobstructed.
An FTP sensor that is skewed or does not have a linear transition from low to high may cause this code to set. Scan tool output controls, snapshot, and plot functions can help detect erratic sensor response. To test the sensor signal under vacuum conditions, use the Quick Snapshot and the Purge/Seal functions to capture data while commanding purge to 20 %, then plot the data to look for erratic sensor operation. A similar test can be done for the pressure side of the sensor operation by applying pressure with the GE-41413-A Evaporative Emissions System Tester (EEST) while taking a snapshot.

Schematic Reference

Engine Controls Schematics (LEA) , Engine Controls Schematics (LUK)

Connector End View Reference

Description and Operation

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Special Tools

GE-41413-A Evaporative Emissions System Tester (EEST)

For equivalent regional tools, refer to Special Tools (Diagnostic Tools) .

Ignition ON, observe the scan tool fuel tank pressure (FTP) sensor parameter. The reading should be between 1.3-1.7 V with the fuel cap removed, and change with fuel tank pressure.
Operate the vehicle within the conditions for running the DTC. You may also operate the vehicle within the conditions that you observed from the freeze frame/failure records data.

Ignition OFF, disconnect the harness connector at the FTP sensor.
Ignition OFF. It may take up to for 2 minutes for all vehicle systems to power down. Test for less than 5 ohms of resistance between the low reference circuit terminal A or 2 and ground. If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the K20 engine control module.
Ignition ON, test for 4.8-5.2 V between the 5 V reference circuit terminal C or 3 and ground. If less than the specified range, test the 5 V reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K20 engine control module. If greater than the specified range, test the 5 V reference circuit for a short to voltage. If the circuit tests normal, replace the K20 engine control module.
Verify the scan tool FTP sensor parameter is less than 0.1 V. If greater than the specified range, test the signal circuit terminal B or 1 for a short to voltage. If the circuit tests normal, replace the K20 engine control module.
Install a 3A fused jumper wire between the signal circuit terminal B or 1 and the 5 V reference circuit terminal C or 3. Verify the scan tool FTP sensor parameter is greater than 4.7 V. If less than the specified range, test the signal circuit for short to ground or an open/high resistance. If the circuit tests normal, replace the K20 engine control module.
If all circuits test normal, test or replace the B150 fuel tank pressure sensor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

«Fuel Tank Pressure Sensor Replacement (NU6)»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions) , «Fuel Tank Pressure Sensor Replacement (NT7)»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions)
«Control Module References»(/buick/regal/v-2009-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for engine control module (ECM) replacement, setup, and programming

Perform the «Diagnostic System Check - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The ECM tests the Evaporative Emission (EVAP) System for a large leak or restrictions to the purge path in the EVAP system. When the enabling criteria has been met the ECM commands the EVAP vent solenoid valve ON and the EVAP purge solenoid valve ON, allowing vacuum into the EVAP system. The ECM monitors the fuel tank pressure (FTP) sensor voltage to verify that the system is able to reach a predetermined level of vacuum within a set amount of time.

DTCs P00C8, P00C9, P0068, P16F3, P0106, P0107, P0108, P0111, P0112, P0113, P0114, P0116, P0117, P0118, P0122, P0123, P0125, P0128, P160E, P160D, P0191, P0192, P0193, P0222, P0223, P0443, P0449, P0452, P0453, P0454, P0502, P0503, P0606, P0722, P0723, P1104, P2100, P2101, P2102, P2103, P2135, P2227, P2228, P2229, P2230 are not set.
The engine is running.
The ignition voltage is between 11-32 V.
The barometric pressure (BARO) is more than 70 kPa.
The fuel level is between 10-90 %.
The purge flow is greater than 3 %
The start-up engine coolant temperature (ECT) is less than 35°C (95°F).
The start-up intake air temperature (IAT) is between 4-30°C (39-86°F).
The start-up ECT and IAT are within 8°C (46°F) of each other.
DTC P0455 runs once per cold start within 10 minutes of start-up.

The EVAP system is not able to achieve or maintain a calibrated level of vacuum within a set amount of time
After setting the DTC for the first time, 2 L (0.5 gal) of fuel must be consumed before setting the DTC for the second time.

DTC P0455 is a Type B DTC.

Inspect for a loose, missing, damaged, or incorrect fuel fill cap.
Inspect for a damaged fuel filler neck seal surface.
A blockage or restriction in the EVAP purge solenoid valve, purge pipe, EVAP canister, or vapor pipe, can cause this DTC to set. Check for vacuum at the purge valve while commanded ON with the scan tool, canister side of hose disconnected and engine running.
The EVAP system can be filled with smoke more quickly and completely by opening the system opposite the end where the smoke is injected. For example, when injecting smoke at the service port remove the fuel fill cap, or temporarily leave the vent open, until smoke is observed, then close the system and continue testing. If using a fuel tank cap adapter at the filler neck, use the J 41413-VLV evaporative emissions (EVAP) service port vent tool at the service port to allow the system to fill faster.
To help locate intermittent leaks using the GE-41413-A evaporative emissions system tester (EEST), move all EVAP components while observing smoke with the GE-41413-SPT high intensity white light.
Individual components can be isolated and tested using adapters in the GE-41413-300 evaporative emissions EVAP cap and plug kit.
A condition may exist where a leak in the EVAP system only exists under a vacuum condition. This type of leak may be detected by using the scan tool Purge/Seal function to create a vacuum in the EVAP system and then observe the FTP parameter for vacuum decay.

Schematic Reference

Engine Controls Schematics (LEA) , Engine Controls Schematics (LUK)

Connector End View Reference

Description and Operation

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Special Tools

CH-48096 Evaporative Emissions (EVAP) Service Access Port Tool
GE-41413-300 Evaporative Emissions EVAP Cap and Plug Kit
GE-41413-A Evaporative Emissions System Tester (EEST)
GE-41413-SPT High Intensity White Light
J-41413-311 Evaporative Emissions (EVAP) Plug
J 41413-VLV Evaporative Emissions (EVAP) Service Port Vent Tool
J-41415-30 Fuel Tank Cap Adapter

For equivalent regional tools, refer to Special Tools (Diagnostic Tools) .

Note. Larger volume fuel tanks and/or those with lower fuel levels may require several minutes for the floating indicator to stabilize. Refer to the GE-41413-A evaporative emissions system tester (EEST) operation manual for detailed instructions in Evaporative Emission System Diagnosis .

Disconnect the purge tube at the quick connector on the EVAP canister side of the Q12 evaporative emission purge solenoid valve. Install the CH-48096 EVAP service access port tool between the disconnected purge tube and the purge solenoid valve. Connect the GE-41413-A evaporative emissions system tester (EEST) to the service access port tool.
Use a scan tool to seal the EVAP system.
Use the flow meter on the GE-41413-A evaporative emissions system tester (EEST), calibrated to 0.51 mm (0.020 inch) to determine that there is no leak in the EVAP system. If a leak is detected, use the GE-41413-A evaporative emissions system tester (EEST) to apply smoke to the EVAP system at the purge tube until the leak is located using the GE-41413-SPT high intensity white light.
To test for a restriction, connect the GE-41413-A evaporative emissions system tester (EEST) nitrogen/smoke hose to the to the J-41413-311 evaporative emissions (EVAP) plug brass cone adapter. Disconnect the hose at the fuel cap end of the J-41415-30 fuel tank cap adapter. Connect the J-41413-311 evaporative emissions (EVAP) plug to the disconnected hose on the J-41415-30 fuel tank cap adapter. Install the J-41415-30 fuel tank cap adapter, filler neck end only, to the vehicle.
Allow the engine to idle.
Use the Purge/Seal function to seal the system with a scan tool.
Command the EVAP Purge Solenoid Valve to 30 %.
The vacuum/pressure gauge on the GE-41413-A evaporative emissions system tester (EEST) and the FTP parameter on the scan tool should both show vacuum. If the vacuum/pressure gauge shows vacuum, but the FTP parameter does not show vacuum, replace the FTP sensor. If neither the FTP parameter nor the vacuum/pressure gauge shows vacuum, repair the restriction in the purge path.
Verify that the vacuum increases to the abort limit on the scan tool or more than 3.2 V, and the values are similar between the scan tool and the vacuum/pressure gauge on the GE-41413-A evaporative emissions system tester (EEST). If the values are not similar, or the voltage did not reach 3.2 V, replace the B150 fuel tank pressure sensor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

«Fuel Tank Pressure Sensor Replacement (NU6)»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions) , «Fuel Tank Pressure Sensor Replacement (NT7)»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions)
«Control Module References»(/buick/regal/v-2009-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for engine control module (ECM) replacement, setup, and programming

Perform the «Diagnostic System Check - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

This DTC tests for undesired intake manifold vacuum flow to the evaporative emission (EVAP) system. The control module seals the EVAP system by commanding the EVAP purge solenoid valve OFF and the EVAP vent solenoid valve ON. The engine control module (ECM) monitors the fuel tank pressure (FTP) sensor to determine if a vacuum is being drawn on the EVAP system. If vacuum in the EVAP system is more than a predetermined value within a predetermined time, this DTC sets.

The following table illustrates the relationship between the ON and OFF states, and the Open or Closed states of the EVAP purge and vent solenoid valves.

Control Module Command	EVAP Purge Solenoid Valve	EVAP Vent Solenoid Valve
ON	Open	Closed
OFF	Closed	Open

DTCs P00C8, P00C9, P0068, P16F3, P0106, P0107, P0108, P0111, P0112, P0113, P0114, P0116, P0117, P0118, P0122, P0123, P0125, P0128, P160E, P160D, P0191, P0192, P0193, P0222, P0223, P0443, P0449, P0452, P0453, P0454, P0502, P0503, P0606, P0722, P0723, P1104, P2100, P2101, P2102, P2103, P2135, P2227, P2228, P2229, P2230 are not set
The ignition voltage is between 11-32 V.
The barometric pressure (BARO) is greater than 70 kPa.
The fuel level is between 10-90 %.
The start-up engine coolant temperature (ECT) is less than 35°C (95°F).
The start-up intake air temperature (IAT) is between 4-30°C (39-86°F).
DTC P0496 runs once per cold start for maximum of 17 min.

The control module detects vacuum during a non-purge condition for a predetermined time.

DTC P0496 is a Type B DTC.

Schematic Reference

Engine Controls Schematics (LEA) , Engine Controls Schematics (LUK)

Connector End View Reference

Description and Operation

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Ignition ON, engine OFF.
Seal the EVAP system using the Purge/Seal function with a scan tool.
Start the engine.
Observe the FTP sensor with a scan tool. The Fuel Tank Pressure Sensor parameter should be less than 1.7 V after 90 s. If the Fuel Tank Pressure Sensor parameter is greater than the specified range, replace the Q12 evaporative emission purge solenoid valve.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Evaporative Emission Canister Purge Solenoid Valve Replacement

Perform the «Diagnostic System Check - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The throttle actuator control (TAC) motor is a DC motor that is part of the throttle body assembly. The TAC motor drives the throttle valve. The engine control module (ECM) controls the TAC motor based on throttle position sensor input. The idle speed is controlled by the ECM based on various inputs. The ECM commands the TAC motor to open or close the throttle valve in order to maintain the desired idle speed.

DTCs P0068, P0101, P0102, P0103, P0112, P0113, P0117, P0118, P0121, P0122, P0123, P0171, P0172, P0201-P204, P0222, P0223, P0261, P0262, P0264, P0265, P0267, P0268. P0270, P0271, P0300-P0304, P0351-P0354, P0461-P0464, P0496, P0627, P0628, P0629, P0722, P1248, P1249, P124A, P124B, P1516, P2066-P2068, P2147, P2148, P2150, P2151, P2153, P2154, P2156, or P2157 are not set.
The barometric pressure (BARO) is greater than 70 kPa.
The engine coolant temperature (ECT) is greater than 60°C (140°F).
The engine run time is greater than 60 s.
The ignition voltage is greater than 11 V.
The transmission is not changing gears.
The torque converter clutch (TCC) is not changing states.
The intake air temperature (IAT) is warmer than -20°C (-4°F).
The vehicle speed is less than 3 km/h (2 mph).
The commanded engine speed is steady within 25 RPM.
The engine is idling for greater than 5 s.
The DTCs run when the above conditions are met.

P0506

The actual engine speed is 91 RPM less than the desired idle speed for 10 s.

P0507

The actual engine speed is 182 RPM greater than the desired idle speed for 10 s.

DTCs P0506 and P0507 are Type B DTCs.

Schematic Reference

Engine Controls Schematics (LEA) , Engine Controls Schematics (LUK)

Connector End View Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Ignition ON.
Verify there are no other DTCs set. If any other DTCs are set Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) for further diagnosis. If no other DTCs are set
Verify the scan tool Throttle Body Idle Airflow Compensation parameter is less than 90 %. 90 % or greater Refer to «Throttle Body Cleaning»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions__throttle-body-cleaning) . If less than 90 %
Engine Idling at the normal operating temperature.
Verify the actual Engine Speed is not 100 RPM less than the Desired Idle Speed. If 100 RPM less than the Desired Idle Speed Refer to Circuit/System Testing If 100 RPM greater than the Desired Idle Speed
Verify the actual Engine Speed is not 200 RPM greater than the Desired Idle Speed. If 200 RPM greater than the Desired Idle Speed Refer to Circuit/System Testing If 200 RPM less than the Desired Idle Speed
Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
Verify the DTC does not set. If the DTC sets Refer to Circuit/System Testing If the DTC does not set
All OK

Verify none of the following conditions exist

P0506

Restricted exhaust
Mechanical conditions that limits engine speed
Parasitic load on the engine-For example, a transmission condition, a belt driven accessory condition. If a condition is found, repair as necessary.

P0507

Vacuum leaks
A throttle valve that does not close correctly
Verify the correct operation of the crankcase ventilation system. Inspect for the following conditions: The routing of the positive crankcase ventilation (PCV) system Vacuum leaks in the PCV system-Refer to «Crankcase Ventilation System Inspection/Diagnosis (Without Turbocharger)»(/buick/regal/v-2009-2013/remont/mechanical/#engine-mechanical-24l__crankcase-ventilation-system-inspectiondiagnosis-without-tur) . If a condition is found, repair as necessary.

Perform the Diagnostic Repair Verification after completing the repair.

Throttle Body Assembly Replacement

Perform the «Diagnostic System Check - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

During a cold start, the engine control module (ECM) commands dual-pulse mode during Open Loop operation to improve cold start emissions. In dual-pulse mode, the injectors are energized twice during each injection event. As with misfire diagnosis, in dual-pulse mode the ECM monitors the crankshaft position sensor and the camshaft position sensors to calculate crankshaft rotation speed. In normal operation, optimum fuel delivery during dual-pulse mode produces a steady crankshaft rotation speed. If the variations exceed a calibrated value, the code will be set.

DTCs P0010, P0011, P0013, P0014, P0090, P0091, P0092, P00C8, P00C9, P00CA, P0101-P0103, P0106-P0108, P0112, P0113, P0116-P0118, P0122, P0123, P0128, P0171, P0172, P0192, P0193, P0201- P0204, P0222, P0223, P0261, P0262, P0264, P0265, P0267, P0268, P0270, P0271, P0300, P0301-P0304, P0335, P0336, P0351-P0354, P0506, P0507, P0627-P0629, P0722, P0723, P1248, P1249, P124A, P124B, P2122, P2123, P2127, P2128, P2135, P2147, P2148, P2150, P2151, P2153, P2154, P2156, P2157 are not set.
The catalyst temperature is less than 500°C (932°F).
The engine coolant temperature is warmer than -10°C (14°F).
The barometric pressure is greater than 60 kPa.
The engine speed is between 250-1900 RPM.
The engine is running and a cold start has been detected.
DTC P050D runs once per cold start.

This DTC will set if the ECM detects variations in crankshaft rotation speed caused by the lack of adequate fuel delivery during dual-pulse mode.

DTC P050D is a Type B DTC.
The ECM disables dual pulse mode and energizes the fuel injector as it would for a warm engine.

DTC P050D is a Type B DTC.

This DTC may be set with a misfire DTC, however the existence of this DTC is a higher priority and indicates the condition to diagnose is related to fuel and/or injectors, not the ignition/spark system.
A restricted fuel injector may cause this DTC to set.
High resistance in the circuits of the injectors could set this DTC without setting an injector DTC. Test the injector circuits of the affected cylinders for a high resistance if you suspect a condition.
A drop in system voltage during cold start may set this DTC.

Schematic Reference

Engine Controls Schematics (LEA) , Engine Controls Schematics (LUK)

Connector End View Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Note. Circuit/System Testing requires cold start. Do not start vehicle prior to connecting scan tool and preparing to evaluate the condition during engine crank.

Start the engine and observe the Cylinder 1-4 Current Misfire Counters during first 500 engine cycles. The Cylinder 1-4 Current Misfire Counters should not be incrementing. If the misfire counters are incrementing on one or more cylinders, verify that the following conditions do not exist: Fuel pressure that is too low or too high-Refer to «Fuel System Diagnosis»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-dtc-p0411-luk-to-dtc-p2635-and-symptom-troubleshooting-diagnosis) . Contaminated fuel-Refer to «Alcohol/Contaminants-in-Fuel Diagnosis»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-dtc-p0411-luk-to-dtc-p2635-and-symptom-troubleshooting-diagnosis) .
If all conditions test normal, replace fuel injectors as indicated by high misfire counts.

Direct Fuel Injector Replacement

Note. Repair Verification requires cold start.

Ignition ON, engine OFF, clear the DTCs with a scan tool.
Start the engine.
Verify the DTC does not reset.

Perform the «Diagnostic System Check - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

This diagnostic applies to internal microprocessor integrity conditions within the engine control module (ECM). This diagnostic also addresses if the ECM is not programmed, or is programmed incorrectly.

P0601, P0602, P0630, P16F3

These DTCs run continuously when the ignition is ON.

P0603, P062F

These DTCs run at power up.

P0604

DTC P0604 runs continuously when the ignition is ON. First memory scan may take up to 30 s.

P0606, P062B

The ignition is ON.
System voltage is greater than 11 V.
These DTCs run continuously when the above conditions are met.

P2610

DTC P2610 runs on ECM power down.

The ECM detects an internal failure or incomplete or incorrect programming.

DTCs P0601, P0602, P0603, P0604, P0606, P062B, P062F, P0630 and P16F3 are Type A DTCs.
DTC P2610 is a Type B DTC.

DTCs P0601, P0602, P0603, P0604, P0606, P062B, P062F, P0630 and P16F3 are Type A DTCs.
DTC P2610 is a Type B DTC.

Low voltage or a momentary loss of power or ground to the ECM may cause a DTC to set. Verify for the following

The battery cables are clean and tight, and the battery is fully charged-Refer to «Battery Inspection/Test»(/buick/regal/v-2009-2013/remont/charging-system/#battery-charging-system-and-starting-system-non-hybrid) .
The ECM ground circuits do not have an open or high resistance
The ECM power circuits do not have an open, short to ground, or high resistance

Schematic Reference

Engine Controls Schematics (LEA) , Engine Controls Schematics (LUK)

Connector End View Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Ignition ON, observe the DTC information with a scan tool. Verify that DTC P0641, P0651, P0697, or P06A3 does not set. If a DTC is set, refer to «DTC P0641, P0651, P0697, or P06A3 (ECM)»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-dtc-p0411-luk-to-dtc-p2635-and-symptom-troubleshooting-diagnosis) for further diagnosis.
Observe the DTC information with a scan tool. DTC P0601, P0602, P0603, P0604, P0606, P062B, P062F, P0630, P16F3, or P2610 should not set.
Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Ignition ON, clear the DTC information with a scan tool.
Observe the scan tool DTC information. Verify that DTC P0602 or P0630 does not set. If DTC P0602 or P0630 failed this ignition, reprogram the K20 ECM. Refer to «Control Module References»(/buick/regal/v-2009-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) . If the DTC resets, replace the K20 ECM.
Observe the DTC information with a scan tool. Verify that DTC P0601, P0603, P0604, P0606, P062B, P062F, P16F3, or P2610 does not set. If a DTC failed this ignition, replace the K20 ECM.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for engine control module replacement, setup, and programming

Perform the «Diagnostic System Check - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The internal fault detection is handled inside the fuel pump control module. No external circuits are involved.

The fuel pump control module runs the program to detect an internal fault when power up is commanded. The only requirements are voltage and ground. This program runs even if the voltage is out of the valid operating range.

The fuel pump control module has detected an internal malfunction.

DTC P0601, P0602, P0603, P0604, P0606 and P062F are type A DTCs.

Description and Operation

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Note. This DTC may be stored as a history DTC without affecting the operation of the module. If stored only as a history DTC and not retrieved as a current DTC, do not replace the module.

Verify that DTC P0602 is not set. If the DTC is set, program the K27 fuel pump control module.
Verify that DTCs P0601, P0603, P0604, P0606, and P062F are not set. If any of the DTCs are set, program the K27 fuel pump control module. If a DTC resets, replace the K27 fuel pump control module.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for fuel pump control module replacement, setup, and programming

Perform the «Diagnostic System Check - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
Fuel Pump Enable	P025A, P0628, P069E	P025A, P0627, P069E	P025A, P0629, P069E

The engine control module (ECM) provides ignition voltage to the fuel pump flow control module whenever the engine is cranking or running. The control module enables the fuel pump flow control module as long as the engine is cranking or running, and ignition system reference pulses are received. While this enable voltage is being received, the fuel pump flow control module supplies a varying voltage to the in-tank fuel pump module in order to maintain the desired fuel line pressure.

The engine speed is greater than 0 RPM.
The ignition voltage is greater than 11 V.
The DTCs run continuously when the conditions above are met.

The ECM detects that the commanded state of the driver and the actual state of the control circuit do not match.
The above condition is met for more than 2 s.

DTCs P0627, P0628, and P0629 are Type B DTCs.

Schematic Reference

Engine Controls Schematics (LEA) , Engine Controls Schematics (LUK)

Connector End View Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Attempt to start the engine. Observe the DTC information with a scan tool. DTC P0627, P0628, or P0629 should not set.
Ignition ON, command the Fuel Pump Enable ON and OFF with a scan tool while observing the following control circuit status parameters: Fuel Pump Enable Circuit Low Voltage Test Status Fuel Pump Enable Circuit Open Test Status Fuel Pump Enable Circuit High Voltage Test Status Each parameter should toggle between OK and Not Run or Not Run and OK.
Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Ignition OFF, disconnect the K27 fuel pump control module harness connector.
Ignition OFF, and all vehicle systems OFF. It may take up to 2 minutes for all vehicle systems to power down. Test for 0 V on the enable circuit terminal 13 of the fuel pump control module. If greater than the specified value, test for a short to voltage on the enable circuit. If the circuit/connections test normal, replace the K20 ECM.
Ignition ON, command the Fuel Pump Enable ON with a scan tool. Test for B+ on the enable circuit terminal 13 of the fuel pump control module. If less than the specified range, test for a short to ground or an open/high resistance on the enable circuit. If the circuit/connections test normal, replace the K20 ECM.
Ignition ON, test for 2-3 V on the enable circuit terminal 13 of the fuel pump control module. If not within the specified range, replace the K20 ECM.
If all circuits/connections test normal, replace the K27 fuel pump control module.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for ECM or fuel pump control module replacement, setup, and programming

Perform the «Diagnostic System Check - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
Fuel Pump Enable	P025A, P0628, P069E	P025A, P0627, P069E	P025A, P0629, P069E

The engine speed is greater than 0 RPM.
The ignition voltage is greater than 11 V.
The DTCs run continuously when the conditions above are met.

The ECM detects that the commanded state of the driver and the actual state of the control circuit do not match.
The above condition is met for a minimum of 2.5 s.

DTCs P0627, P0628, and P0629 are Type B DTCs.

Schematic Reference

Engine Controls Schematics (LEA) , Engine Controls Schematics (LUK)

Connector End View Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Attempt to start the engine. Observe the DTC information with a scan tool. DTC P0627, P0628, or P0629 should not set.
Ignition ON, command the Fuel Pump Enable ON and OFF with a scan tool while observing the following control circuit status parameters: Fuel Pump Enable Circuit Low Voltage Test Status Fuel Pump Enable Circuit Open Test Status Fuel Pump Enable Circuit High Voltage Test Status Each parameter should toggle between OK and Not Run or Not Run and OK.
Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Ignition OFF, disconnect the K27 fuel pump control module harness connector.
Ignition OFF, and all vehicle systems OFF. It may take up to 2 minutes for all vehicle systems to power down. Test for 0 V on the enable circuit terminal 20 of the fuel pump control module. If greater than the specified value, test for a short to voltage on the enable circuit. If the circuit/connections test normal, replace the K20 ECM.
Ignition ON, command the Fuel Pump Enable ON with a scan tool. Test for B+ on the enable circuit terminal 20 of the fuel pump control module. If less than the specified range, test for a short to ground or an open/high resistance on the enable circuit. If the circuit/connections test normal, replace the K20 ECM.
Ignition ON, test for 2-3 V on the enable circuit terminal 20 of the fuel pump control module. If not within the specified range, replace the K20 ECM.
If all circuits/connections test normal, replace the K27 fuel pump control module.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for ECM or fuel pump control module replacement, setup, and programming

Perform the «Diagnostic System Check - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The engine control module (ECM) has 4 internal 5 V reference circuits. Each internal reference circuit provides a 5 V reference for more than one sensor. A short to ground or short to voltage on one external 5 V reference circuit will affect the other components connected to the same internal reference circuit.

These DTCs run continuously when the ignition voltage is greater than 6.4 V.

The 5 V reference circuit voltage is greater or less than a predetermined threshold.

DTCs P0641, P0651, P0697, and P06A3 are Type A DTCs.

DTC P0641

The 5 V reference 1 circuit provides 5 V to the following sensors

Fuel tank pressure (FTP) sensor
Fuel rail pressure (FRP) sensor
A/C refrigerant pressure sensor
Mass air flow/intake air temperature sensor, LEA engine
Exhaust camshaft position sensor
Intake camshaft position sensor

DTC P0651

The 5 V reference 2 circuit provides 5 V to the following sensors

Brake pedal position sensor, LEA engine
Crankshaft position sensor
Secondary air injection pressure sensor, if equipped

DTC P0697

The 5 V reference 3 circuit provides 5 V to the following sensors

Manifold absolute pressure (MAP) sensor
Accelerator pedal position sensor 2

DTC P06A3

The 5 V reference 4 circuit provides 5 V to the following sensors

Throttle position sensor
Accelerator pedal position sensor 1

It may be possible to locate the fault by disconnecting one component at a time from the affected 5 V reference circuit while viewing the 5 V Reference Circuit parameter on the scan tool. The scan tool parameter will change from Malfunction to OK when the source of the fault is disconnected. If all 5 V reference components have been disconnected and a fault is still indicated, the fault may exist in the wiring harness.

Schematic Reference

Engine Controls Schematics (LEA) , Engine Controls Schematics (LUK)

Connector End View Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Ignition ON, observe the DTC information with a scan tool. DTC P0641, P0651, P0697, or P06A3 should not set.
Observe the circuit status parameters listed below: 5 V Reference 1 Circuit Status 5 V Reference 2 Circuit Status 5 V Reference 3 Circuit Status 5 V Reference 4 Circuit Status Each parameter should display OK.
Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Ignition OFF, disconnect the harness connector of all appropriate sensors for the applicable DTC. Refer to Diagnostic Aids.
Ignition ON, test for 4.8-5.2 V between one of the affected 5 V reference circuits and ground. If less than the specified range, test for a short to ground on the 5 V reference circuit for each of the affected components. If all circuits test normal, replace the K20 ECM. If greater than the specified range, test for a short to voltage on the 5 V reference circuit for each of the affected components. If all circuits test normal, replace the K20 ECM.
Connect each component associated with the affected 5 V reference circuit one at a time while monitoring the appropriate scan tool 5 V Reference Voltage 1, 2, 3, or 4 parameter. Verify the voltage remains between 4.8-5.2 V. If not within the specified range when a component is connected, test the signal circuit of that component for a short to voltage. If the circuit tests normal, replace the component.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

«Accelerator Pedal with Position Sensor Assembly Replacement»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions)
«Air Conditioning (A/C) Refrigerant Pressure Sensor Replacement»(/buick/regal/v-2009-2013/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning)
«Camshaft Position Sensor Replacement - Intake»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions)
«Camshaft Position Sensor Replacement - Exhaust»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions)
«Crankshaft Position Sensor Replacement»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions)
«Fuel Injection Fuel Rail Fuel Pressure Sensor Replacement»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions)
«Fuel Tank Pressure Sensor Replacement (NU6)»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions) , «Fuel Tank Pressure Sensor Replacement (NT7)»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions)
«Manifold Absolute Pressure Sensor Replacement»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions)
«Mass Airflow Sensor with Intake Air Temperature Sensor Replacement»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions)
«Secondary Air Injection Check Valve Replacement»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions)
«Throttle Body Assembly Replacement»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions)
«Control Module References»(/buick/regal/v-2009-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for engine control module replacement, setup, and programming

Perform the «Diagnostic System Check - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
5 V Reference	P0641	P0641, P06A6	P0641	P06A6
Signal	P018C	P018B, P018C	P018D	P018B
Low Reference		P0641, P06A6		P06A6

The fuel pressure sensor is located on the fuel line. The fuel pressure sensor monitors the fuel pressure in the fuel line. The fuel pump control module monitors the voltage signal from the fuel pressure sensor.

The ignition is on.

The fuel pump control module detects that the fuel pressure 5 V reference is above or below a predetermined voltage threshold.

DTCs P0641 and P06A6 are Type A DTCs.

Using the Failure Records data may help locate an intermittent condition. If you cannot duplicate the DTC, the information in the Failure Records can help determine how many miles since the DTC set. The Fail Counter and Pass Counter can help determine how many ignition cycles that the diagnostic test reported a pass and/or a fail.

Schematic Reference

Engine Controls Schematics (LEA) , Engine Controls Schematics (LUK)

Connector End View Reference

Description and Operation

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Ignition OFF, disconnect harness connector of the B47 fuel pressure sensor.
Ignition OFF, test for less than 1.0 ohms between the low reference circuit terminal 2 and ground. If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the K27 fuel pump control module.
Ignition ON, test for 4.8-5.2 V between the 5 V reference circuit terminal 3 and ground. If less than the specified range, test the 5 V reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K27 fuel pump control module. If greater than the specified range, test the 5 V reference circuit for a short to voltage. If the circuit tests normal, replace the K27 fuel pump control module.
If all circuits test normal, replace the B47 fuel pressure sensor.

Perform the Diagnostic Repair Verification after completing the repair.

«Fuel Pressure Sensor Replacement - Fuel Feed Pipe»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions)
«Control Module References»(/buick/regal/v-2009-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for fuel pump control module replacement, programming and setup

Perform the «Diagnostic System Check - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Circuit	Short to Ground	Open/High Resistance	Short to Voltage
Ignition Voltage	P0650	P0650
MIL Control	P0650*	P0650	P0650
* The MIL remains ON

The malfunction indicator lamp (MIL) illuminates to inform the driver that an emission system fault has occurred and the engine control system requires service. Ignition voltage is supplied directly to the MIL and, when the emission fault occurs, the engine control module (ECM) turns the MIL ON by grounding the MIL control circuit. Under normal operating conditions, the MIL should be ON only when the ignition is ON and the engine is OFF.

The engine speed is greater than 80 RPM.
The ignition voltage is between 11-32 V.
The DTC runs continuously when the above conditions are met.

The ECM detects an open, a short to ground, or a short to voltage on the circuit that controls the MIL.

DTC P0650 is a Type B DTC.

If the condition is intermittent, move the related harnesses and connectors with the ignition ON and the engine OFF, and with the engine operating while monitoring the scan tool MIL control circuit status parameters. The MIL control circuit status parameters will change from OK or Not Run to Malfunction if there is a condition with the circuit or a connection.

Schematic Reference

«Engine Controls Schematics (LEA)»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-wiring-schematic-diagrams) , «Engine Controls Schematics (LUK)»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-wiring-schematic-diagrams)
«Instrument Cluster Schematics»(/buick/regal/v-2009-2013/remont/gauges-instrument-panels/#instrument-panel-system-displays-and-gauges)

Connector End View Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Ignition ON, command the MIL ON and OFF with a scan tool. The MIL should turn ON and OFF as commanded.
Command the MIL ON and OFF with a scan tool while observing the following control circuit status parameters: The MIL Control Circuit Low Voltage Test Status The MIL Control Circuit Open Test Status The MIL Control Circuit High Voltage Test Status Each parameter should display OK or Not Run.
Engine running, command the MIL ON and OFF with a scan tool while observing the following control circuit status parameters: The MIL Control Circuit Low Voltage Test Status The MIL Control Circuit Open Test Status The MIL Control Circuit High Voltage Test Status Each parameter should display OK or Not Run.
Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Ignition OFF, disconnect the X1 harness connector at the K20 engine control module.
Ignition ON, the malfunction indicator lamp should not illuminate. If the malfunction indicator lamp is illuminated, test the malfunction indicator lamp control circuit terminal 46 X1 for a short to ground. If the circuit tests normal, replace the P16 instrument cluster.
Connect a 3 A fused jumper wire between the malfunction indicator lamp control circuit terminal 46 X1 and ground. The malfunction indicator lamp should illuminate. If the malfunction indicator lamp illuminates, replace the K20 engine control module. If the malfunction indicator lamp does not illuminate, test the malfunction indicator lamp control circuit terminal 46 X1 for a short to voltage or an open/high resistance. If the malfunction indicator lamp control circuit tests normal, test the instrument cluster ignition voltage circuit for a short to ground or open/high resistance. If the circuit tests normal, replace the P16 instrument panel cluster/bulb.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

«Instrument Cluster Replacement»(/buick/regal/v-2009-2013/remont/gauges-instrument-panels/#instrument-panel-system-displays-and-gauges)
«Control Module References»(/buick/regal/v-2009-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for engine control module replacement, setup, and programming

Perform the «Diagnostic System Check - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Circuit	Short to Ground	Open/High Resistance	Short to Voltage
Relay Coil Supply Voltage		P0685, P0689, P1682
Relay Control Circuit	P0690	P1682	P0685, P0689, P1682
Relay Feedback Circuit	P0689, P1682	P0689, P1682	P0690

Engine Controls Ignition Relay

Circuit	Short to Ground	Open/High Resistance	Short to Voltage
Ignition 1 Signal, Ignition Run Relay	1	1	2
1. No Crank condition. 2. Engine continues to operate with ignition OFF.

Ignition Run Relay

Circuit	Short to Ground	Open	Short to Voltage
Operating Conditions: Component commanded OFF Parameter Normal Range: The following illustrates the normal parameter state with no circuit conditions: Component OFF - OK for Open/Low Voltage test and Not Run for High Voltage test Component ON - Not Run for Open/Low Voltage test and OK for High Voltage test
Battery Voltage	Malfunction	Malfunction
Engine Controls Ignition Relay Control Circuit	Malfunction	Malfunction	Not Run

Engine Controls Ignition Relay Control Circuit Low Voltage, Open, and High Voltage Test Status - Component Commanded OFF

Circuit	Short to Ground	Open	Short to Voltage
Operating Conditions: Component commanded ON Parameter Normal Range: The following illustrates the normal parameter state with no circuit conditions: Component OFF - OK for Open/Low Voltage test and Not Run for High Voltage test Component ON - Not Run for Open/Low Voltage test and OK for High Voltage test
Battery Voltage	Not Run	Not Run
Engine Controls Ignition Relay Control Circuit	Not Run	Not Run	Malfunction

Engine Controls Ignition Relay Control Circuit Low Voltage, Open, and High Voltage Test Status - Component Commanded ON

There are 2 ignition voltage circuits supplied to the engine control module (ECM). One is supplied by the engine controls ignition relay and the other is supplied by the ignition run relay. The ECM monitors and compares the ignition voltage supplied by the two relays.

P0685

The DTC runs continuously when the ignition voltage is greater than 11 V.

P0689

The engine controls ignition relay is commanded ON.
The ignition voltage is greater than 11 V.
DTC P0685 is not set.
The DTC runs continuously when the above conditions are met.

P0690

The engine controls ignition relay is commanded ON.
DTC P0685 is not set.
The DTC runs continuously when the above conditions are met.

P1682

The engine controls ignition relay is commanded ON.
The ignition voltage is greater than 5.5 V.
The DTC runs continuously when the above conditions are met.

P0685

The ECM detects that the commanded state of the driver and the actual state of the control circuit do not match for greater than 2 s.

P0689

The engine controls ignition relay voltage is less than 5 volts for greater than 5 s.

P0690

The ECM detects the engine controls ignition relay feedback circuit is greater than 4 V when the relay is commanded OFF.
The condition is present for greater than 5 s.

P1682

The ECM detects that there is greater than 3 V difference between the ignition run relay signal and the engine controls ignition relay signal circuits for less than 1 s.

DTC P1682 is a Type A DTC.
DTCs P0685 and P0690 are Type B DTCs.
DTC P0689 is a Type C DTC.

DTC P1682 is a Type A DTC.
DTCs P0685 and P0690 are Type B DTCs.
DTC P0689 is a Type C DTC.

The engine controls ignition relay may also be labeled the powertrain relay, the engine control module relay, or the main relay. The ignition run relay may also be labeled the run/crank relay, the ignition 1 relay, the ignition main relay, or the ignition relay.

Schematic Reference

«Engine Controls Schematics (LEA)»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-wiring-schematic-diagrams) , «Engine Controls Schematics (LUK)»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-wiring-schematic-diagrams)
«Power Distribution Schematics»(/buick/regal/v-2009-2013/remont/body-electrical/#wiring-systems-and-power-management-wiring-schematics-and-wiring-harness-routing-diagrams)

Connector End View Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Electrical Center Identification Views»(/buick/regal/v-2009-2013/remont/electrical-component-locations/#wiring-systems-and-power-management-component-locator-electrical-center-identification-views)
«Testing for Intermittent Conditions and Poor Connections»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Ignition ON, command the Engine Controls (EC) Ignition Relay ON and OFF with a scan tool while observing the parameters listed below: Engine Controls Ignition Relay Control Circuit Low Voltage Test Status Engine Controls Ignition Relay Control Circuit Open Test Status Engine Controls Ignition Relay Control Circuit High Voltage Test Status Each parameter should display OK or Not Run in each commanded state.
Ignition ON, observe the DTC information with a scan tool. DTC P0685, P0689, P0690, or P1682 should not set.
Ignition ON, observe the scan tool Ignition 1 Voltage Signal and the Engine Controls Ignition Relay Feedback Signal parameters. There should be less than 3 V difference between the two parameters.
Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Note. You must perform the Circuit/System Verification before proceeding with Circuit/System Testing unless sent here from Engine Cranks But Does Not Run.

Ignition OFF, disconnect the KR75 engine controls ignition relay.
Verify that a test lamp illuminates between ground and the relay circuit terminals listed below: Terminal 2 Terminal 3 If the test lamp does not illuminate, test the relay battery voltage circuit for an open/high resistance.
Ignition ON, verify that a test lamp does not illuminate between the ignition voltage circuit terminal 5 and ground. If the test lamp illuminates, test the ignition voltage circuit for a short to voltage.
Connect a 20 A fused jumper wire between the relay switch B+ circuit terminal 3 and the relay switch ignition voltage circuit terminal 5.
Ignition ON, observe the scan tool Engine Controls Ignition Relay Feedback Signal parameter. The ECM should communicate, and the parameter should display B+. If not the specified value, or the ECM does not communicate, test the ignition voltage circuit between the engine controls ignition relay and the ECM for a short to ground or for an open/high resistance. If the circuit/connections test normal, replace the K20 ECM.
Ignition OFF, connect a DMM set to the diode setting between control circuit terminal 1 and ground. Verify the DMM displays OL. If not the specified value, test the control circuit for a short to ground. If the circuit tests normal, replace the K20 ECM.
Ignition ON, verify the DMM displays less than 1 V. If not the specified range, test the control circuit for a short to voltage, or an open/high resistance. If the circuit tests normal, replace the K20 ECM.
If all circuits test normal, replace the KR75 engine controls ignition relay.

Remove the KR75 engine controls ignition relay.
Test for one of the following resistance specifications between terminals 2 and 1 of the KR75 engine controls ignition relay: 70-110 ohms 200-250 ohms If not within the specified range, replace the KR75 engine controls ignition relay.
Test for infinite resistance between the following terminals of the KR75 engine controls ignition relay: 3 and 1 3 and 5 3 and 2 2 and 5 If not the specified value, replace the KR75 engine controls ignition relay.
Install a 20 A fused jumper wire between relay terminal 2 and 12 V. Install a jumper wire between relay terminal 1 and ground. Test for less than 2 ohms between terminals 3 and 5. If greater than the specified range, replace the KR75 engine controls ignition relay.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

«Relay Replacement (Within an Electrical Center)»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-repair-instructions) , «Relay Replacement (Attached to Wire Harness)»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-repair-instructions)
«Control Module References»(/buick/regal/v-2009-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, setup, and programming

Perform the «Diagnostic System Check - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) Prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The fuel pump control module uses the serial data network to signal the engine control module (ECM) that the fuel pump control module is requesting malfunction indicator lamp (MIL) illumination. A DTC is set in the fuel pump control module, and the request for MIL illumination is sent when the fuel pump control module determines that a failure that affects emissions has occurred in the fuel pump control system. When the ECM receives the message from the fuel pump control module, DTC P069E will set in the ECM.

The ignition is ON, or the engine is running for greater than 3 s.

The fuel pump control module requests the ECM to illuminate the MIL.

DTC P069E is a Type A DTC.
DTC P069E will continue to be current or active as long as the fuel pump control module is requesting MIL illumination.

DTC P069E is a Type A DTC.

Communication codes, U-codes, as well as powertrain codes, P-codes, set in the fuel pump control module will cause the fuel pump control module to request DTC P069E to be set in the ECM.

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

DTC P069E is an informational DTC. If there are no engine controls or communication DTCs, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) for diagnosis of fuel pump control module DTCs. Do not replace the ECM for this DTC.
Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Perform the «Diagnostic System Check - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each of the diagnostic category.

Diagnostic trouble code (DTC) P0700 is an informational DTC that indicates that an emission related transmission DTC has set in the transmission control module (TCM). The engine control module (ECM) turns ON the malfunction indicator lamp (MIL) when the TCM sends a message over the serial data circuit requesting MIL illumination. The DTC information for the ECM will only display DTC P0700, and the ECM Freeze Frame/Failure Records data will display the engine operating conditions that were present when the transmission DTC was set. The TCM Freeze Frame/Failure records data is available from the DTC that was set in the TCM.

The ignition is ON or the engine is operating.
DTC P0700 runs continuously.

The ECM receives a serial data message from the TCM requesting the ECM to turn ON the MIL.

DTC P0700 is a Type A DTC.

Communication codes, U-codes, as well as powertrain codes, P-codes, set in the TCM can cause the TCM to request DTC P0700 to be set in the ECM.

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Verify that there are no engine controls or communication DTCs set. If a DTC is set Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) for diagnosis of engine control or communications DTCs. If a DTC is not set
Verify that there are no transmission control module DTCs set. If a DTC is set Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) for diagnosis of transmission control module DTCs. If a DTC is not set
Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
Verify the DTC does not set. If the DTC sets Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) . If the DTC does not set
All OK.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Perform the «Diagnostic System Check - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

This DTC indicates the hybrid powertrain control module has set an emission related hybrid powertrain DTC. The hybrid powertrain control module sends a message via the serial data circuit to the engine control module (ECM) requesting illumination of the malfunction indicator lamp (MIL). When the ECM receives the message, DTC P0AC4 will set. The DTC information for the ECM will only display DTC P0AC4, but the freeze frame/failure records data may display the hybrid powertrain DTC that set.

Vehicle ON for greater than 3 s.
Ths DTC runs continuously when the above condition is met.

The hybrid powertrain control module has set an emission related DTC.

DTC P0AC4 is a Type A DTC.

Description and Operation

Hybrid Modes of Operation Description

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Note. Correct any engine control DTCs before diagnosing hybrid powertrain control module DTCs.

DTC P0AC4 is an informational DTC. If there are no other engine control DTCs set, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) for diagnosis of hybrid powertrain control module DTCs.
Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Perform the «Diagnostic System Check - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
Ignition 1 Voltage	P0096, P0097, P0102, P11C2, P2199	P0096, P0097, P0102, P11C2, P2199		P0096
Intake Air Humidity Sensor Signal	P0096, P0097, P11C3, P2199	P0096, P0097, P11C2, P2199	P0096*, P0097, P11C2, P2199	P0096
Ground		P0096, P0097, P0102, P11C2, P2199		P0096
*Internal ECM or sensor damage may occur if the circuit is shorted to B+.

ERROR - table Title is missing for titlesource=author-entry

Circuit	Short to Ground	Open or High Resistance	Short to Voltage
Operating Conditions: Engine Running Parameter Normal Range: Varies with ambient humidity and temperature; and engine bay conditions
Ignition 1	0 %	0 %
Intake Air Humidity Signal	100 %	0 %	0 %*
Ground		0 %
*Internal ECM or sensor damage may occur if the circuit is shorted to B+

Intake Air Humidity

The humidity sensor measures the ambient humidity of the air in the sensor bore. The signal varies with intake air humidity and is displayed by the scan tool as duty cycle %. The ECM applies 5 V to the circuit. The signal circuit is shared by the humidity sensor and the intake air temperature (IAT) sensor 2. Ignition voltage and ground circuits are also supplied to the multifunction intake air sensor's internal circuits for these sensors

IAT sensor 2
Humidity sensor
MAF sensor

The multifunction intake air sensor houses the following

IAT sensor 1
IAT sensor 2
Humidity sensor
MAF sensor
BARO pressure sensor

Conditions for Running the DTCs

P11C2, P11C3, and P11C4

The ignition is ON.
The Ignition 1 voltage is at least 11 V for longer than 0.9 s.
These DTCs run continuously within the enabling conditions.

Conditions for Setting the DTCs

P11C2

The ECM detects that the humidity sensor signal is less than or equal to 5 % for greater than 5 s.

P11C3

The ECM detects that the humidity sensor signal is greater than or equal to 95 % for greater than 5 s.

P11C4

The ECM monitors the IAT sensor signal every 0.1 s, to determine if the signal has changed more than 80 %. The DTC fails when the condition exists for longer than 4 s.

DTCs P11C2, P11C3, P11C4 are Type B DTCs.

The Intake Air Humidity Signal parameter displays the measured humidity within the air intake system and may differ from atmospheric humidity measured outside the air intake system.
With the ignition ON, the engine OFF, if the engine is cold, a properly functioning humidity sensor will gradually increase the scan tool Intake Air Humidity Signal parameter. This is due to the heat that is generated by the multifunction intake air sensor heating elements.
The humidity sensor and the IAT sensor 2 signals are sent to the ECM on the same circuit. If the Intake Air Humidity parameter displays the value: 0 % or 100 %, and there are also IAT Sensor 2 DTCs, check for a circuit problem.
With the ignition ON, the engine OFF, if the engine is cold, a properly functioning IAT sensor 2 will gradually increase the scan tool IAT Sensor 2 parameter. This is due to the heat that is generated by the multifunction intake air sensor heating elements.

Schematic Reference

Engine Controls Schematics (LEA) , Engine Controls Schematics (LUK) Engine Controls Schematics

Connector End View Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References Control Module References for scan tool information

Special Tools

«J 38522»(/buick/regal/v-2009-2013/remont/automatic-trans/#automatic-transmission-6t406t456t50-special-tools-and-equipment) Variable Speed Generator
For equivalent regional tools, refer to «Special Tools (Diagnostic Tools)»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-special-tools-and-equipment__special-tools-diagnostic-tools) .

Ignition ON. Observe the scan tool IAT Sensor 1 and 2 parameters. The readings should be within 30°C (54°F) of each other.
Engine running, observe the scan tool Intake Air Humidity parameter. Depending on the current ambient humidity and temperature; engine bay conditions; and the vehicle operating conditions, the reading should be between 5 and 90 %.
Operate the vehicle within the conditions for running the DTC to verify that the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the freeze frame/failure records data.

Ignition OFF, disconnect the harness connector at the B75C multifunction intake air sensor.
Ignition OFF, all vehicle systems OFF, test for less than 5 ohms between the ground circuit terminal 7 and ground. If greater than the specified range, test the ground circuit for an open/high resistance.
Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal 5 and ground. If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance. If the circuit tests normal and the fuse is open, test all the components connected to the circuit and repair or replace as necessary.
Ignition ON, test for 4.8-5.2 V between the humidity signal circuit terminal 8 and ground. If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K20 engine control module. NOTE: If the signal circuit is shorted to a voltage the ECM or the sensor may be damaged. If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the K20 engine control module.
Ignition OFF, connect the red lead of the «J 38522»(/buick/regal/v-2009-2013/remont/automatic-trans/#automatic-transmission-6t406t456t50-special-tools-and-equipment) to the signal circuit terminal 8 at the harness connector. Connect the battery voltage supply to B+, and the black lead to ground.
Set the «J 38522»(/buick/regal/v-2009-2013/remont/automatic-trans/#automatic-transmission-6t406t456t50-special-tools-and-equipment) to the following specifications. Signal switch to 5 V Frequency switch to 250 Hz Duty Cycle switch to 50 % (Normal)
Ignition ON, observe the scan tool Intake Air Humidity parameter. The scan tool parameter should be between 45-55 %. If the parameter is not within the specified range, replace the K20 engine control module.
If all circuits test normal, test or replace the B75C multifunction intake air sensor.

Perform the Diagnostic Repair Verification after completing the repair.

«Mass Airflow Sensor with Intake Air Temperature Sensor Replacement»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions) for multifunction intake air sensor replacement.
«Control Module References»(/buick/regal/v-2009-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for engine control module replacement, programming, and setup.

Perform the «Diagnostic System Check - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The engine control module (ECM) supplies voltage to the fuel pump control module when the ECM detects that the ignition is on. The voltage from the ECM to the fuel pump control module remains active for 2 seconds, unless the engine is in crank or run. While this voltage is being received, the fuel pump control module supplies a varying voltage to the fuel tank pump module in order to maintain the desired fuel rail pressure.

The engine is running.

The fuel pump control module detects an over-temperature fault.

DTCs P064A and P1255 are Type A DTCs.

Schematic Reference

Engine Controls Schematics (LEA) , Engine Controls Schematics (LUK)

Connector End View Reference

Description and Operation

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Verify that DTC P0231, P0232 or P023F are not set. If any of those codes are set, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) .
Ensure that the entire undercarriage of the vehicle is clean, especially around the area where the K27 fuel pump control module is located. Clear all codes from the K27 fuel pump control module and test drive the vehicle. Verify that DTC P1255 or P064A do not set. If DTC P1255 or P064A reset, replace the K27 fuel pump control module.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for fuel pump control module replacement, setup, and programming

Perform the «Diagnostic System Check - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
Ignition Coil Supply Voltage Bank 1	P0201, P0203, P0205, P0300, P0351, P0353, P0355, P135A	P0201, P0203, P0205, P0300, P0351, P0353, P0355, P135A

The ignition system on this engine uses an individual module/coil for each cylinder. The engine control module (ECM) monitors the ignition voltage from the fuse of each bank of coils to the ECM. The ECM uses this information to determine if the misfire is ignition coil voltage related.

The ignition is ON.
The ignition module supply voltage is less than 2.5 V.
The DTCs run continuously when the above condition is met.

The ECM detects a fault in an ignition coil control circuit for 50 out of 63 samples. Each sample runs on a 6.25 ms loop.

DTC P135A is a Type A DTC.

Schematic Reference

Engine Controls Schematics (LEA) , Engine Controls Schematics (LUK)

Connector End View Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Description and Operation

«Electronic Ignition System Description»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-description-and-operation__electronic-ignition-system-description)
«Engine Control Module Description»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-description-and-operation__engine-control-module-description)

Electrical Information Reference

«Circuit Testing»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Wiring Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Engine Control Module Scan Tool Information (LUK) , Engine Control Module Scan Tool Information (LEA) for scan tool information

With the ignition ON, observe the Ignition Coil Supply Voltage Bank 1 parameter for each cylinder.

The parameter should display ON.

Note. The ignition circuit supplies voltage to other components. Make sure you test all circuits for a short to ground or test all components for being shorted that share the ignition circuit.

Ignition OFF, disconnect the harness connector at the appropriate T8 ignition coil.
Ignition ON, verify that a test lamp illuminates between the ignition voltage circuit terminal D and ground of each T8 ignition coil. If the test lamp does not illuminate, test the circuit for a short to ground or an open/high resistance. If the circuit tests normal, with the ignition OFF, disconnect the harness connector at each T8 ignition coil and monitor the fuse while individually connecting each T8 ignition coil. If the fuse opens, replace the appropriate T8 ignition coil.
Ignition OFF, disconnect the K20 ECM harness connector X1.
Ignition ON, connect a test lamp between the X1 67 ignition voltage circuit and ground. The test lamp should illuminate on each circuit. If the test lamp does not illuminate, test the ignition circuit for an open/high resistance.
If all circuits/connections test normal, replace the K20 ECM.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

«Ignition Coil Replacement»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions)
«Control Module References»(/buick/regal/v-2009-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for K20 ECM replacement, setup, and programming

Perform the «Diagnostic System Check - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The catalytic converter must be warmed to efficiently reduce the emissions. The cold start strategy is to reduce the amount of time it takes to warm the catalytic converter. During a cold start, the engine idle speed is elevated and spark timing is retarded to allow the catalyst to warm quickly. This diagnostic monitors the following to build an exhaust energy model

Engine speed
Spark advance
Throttle position
Engine airflow
Engine coolant temperature
Engine run time
Park/Neutral position
Vehicle speed

The actual model is then compared to the expected exhaust energy model.

The engine is running, and a cold start has been detected.
The vehicle speed is less than 2 km/h (1 mph).
The catalyst temperature is greater than 1, 000°C (1, 832°F).
The coolant temperature is greater than 56°C (133°F).
The engine run time is greater than 18 s.
The engine is at idle with no input from the accelerator pedal for greater than 5 s.
DTCs P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0220, P0222, P0223, P0201, P0202, P0203, P0204, P0300, P0335, P0336, P0351, P0352, P0353, P0506, P0507, P0601, P0602, P0603, P0604, P0606, P0607, P062F, P0641, P0651, P1516, P1682, P2101, P2119, P2120, P2122, P2123, P2125, P2127, P2128, P2135, P2138, P2176, P2610 are not set.
This DTC runs within 15 seconds within the first 2 minutes of start-up. This diagnostic runs once per trip when a cold start has been determined.

The actual exhaust energy model does not match the expected exhaust energy model.

DTC P1400 is a Type A DTC.

Any loading of the engine that lowers engine RPM, such as partial application of the clutch, A/C cycling, etc. during the first 120 seconds of the engine run time may set this DTC.

Allow the engine to cool until the catalyst temperature is less than 500°C (932°F) and the engine coolant is greater than -10°C (+14°F).
Idle the engine for greater than 2 minutes.
Observe the scan tool DTC information. DTC P1400 should not set.
Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Inspect the air intake system for the following: Modified, damaged, or restricted Dirty or deteriorating air filter element Crankcase ventilation system for correct operation. Water intrusion Vacuum leak and other unmetered air downstream of the MAF sensor Intake manifold leak
Inspect the exhaust system for the following: Water intrusion Exhaust leak Damaged, restricted, modified or enhanced exhaust system.
Inspect the engine mechanical for items that could alter the air flow into the combustion chamber.

Perform the «Diagnostic System Check - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Circuit	Short to Ground	High Resistance	Open	Short to Voltage	Signal Performance
TAC Motor Control Closed	P1516, P2101, P2176	P1516, P2101, P2176	P1516, P2101, P2176	P0690, P1516, P2101, P2176	P1516, P2101, P2176
TAC Motor Control Open	P1516, P2101, P2119, P2176	P1516, P2101, P2176	P1516, P2101, P2176	P0690, P1516, P2101, P2176	P1516, P2101, P2176

The throttle body assembly contains a contact-less inductive throttle position sensing element that is managed by a customized integrated circuit. The throttle position sensor is mounted within the throttle body assembly and is not serviceable. The engine control module (ECM) supplies the throttle body with a 5 V reference circuit, a low reference circuit, an H-bridge motor directional control circuit, and an asynchronous signal/serial data circuit. The asynchronous signal means communication is only going from the throttle body to the ECM. The throttle body cannot receive data from the ECM over the signal/serial data circuit. The throttle position sensor provides a signal voltage that changes relative to throttle blade angle. The customized integrated circuit translates the voltage based position information into serial data using the Society of Automotive Engineers (SAE) J2716 Single Edge Nibble Transmission (SENT) protocol. The throttle position sensor information is transmitted between the throttle body and the ECM on the signal/serial data circuit. The ECM decodes the serial data signal and is used as voltages for throttle position sensor 1 and 2.

The ECM controls the throttle valve by applying a varying voltage to the control circuits of the throttle actuator control (TAC) motor. The ECM monitors the duty cycle that is required to actuate the throttle valve. The ECM monitors the throttle position sensor signal/serial data circuit to determine the actual throttle valve position.

P1516

The run/crank or powertrain relay voltage is greater than 6.4 V and reduced power is not active.
DTC P1516 runs continuously when the above conditions are met.

P2101

DTC P1682 is not set.
The run/crank or powertrain relay voltage is greater than 6.4 V and reduced power is not active.
The engine is running or the following conditions are met: The engine is not running. The ignition voltage is greater than 11 V. The TAC system is not in the Battery Saver mode. The ECM is commanding the throttle. The ECM has learned the minimum throttle position.
DTC P2101 runs continuously when the above conditions are met.

P2119

DTCs P0122, P0123, P0222, P0223, or P06A3 is not set.
The run/crank or powertrain relay voltage is greater than 6.4 V and reduced power is not active.
The system is not in the Battery Save mode.
The ECM is not commanding the throttle.
DTC P2119 runs continuously when the above conditions are met.

P2176

The run/crank or powertrain relay voltage is greater than 6.4 V and reduced power is not active.
DTC P2176 runs continuously when the above conditions are met.

P1516

The ECM detects an unstable throttle position for greater than 1 s.

P2101

The ECM detects the actual throttle position does not match the predicted throttle position for greater than 1 s. Or
The ECM detects the throttle control is driving the throttle in the incorrect direction or exceed the reduced power limit.

P2119

The ECM determines that the throttle blade did not return to the rest position within 1 s.

P2176

The ECM detects that both throttle position sensors were greater than a predetermined voltage during the minimum throttle learn procedure for greater than 2 s.

DTCs P1516, P2101, and P2176 are type A DTCs.
DTC P2119 is a type C DTC.
The ECM commands the TAC system to operate in the Reduced Engine Power mode.
A message center or an indicator displays Reduced Engine Power.
Under certain conditions, the control module commands the engine OFF.

DTCs P1516, P2101, and P2176 are type A DTCs.
DTC P2119 is a type C DTC.

Inspect for a condition in which the throttle valve may have been held open. For example, ice may have formed in the throttle bore causing the throttle valve not to close.
A high resistance condition on the throttle position and throttle actuator control circuits could cause a DTC to set.
A low battery condition may cause a DTC to set.

Schematic Reference

Engine Controls Schematics (LEA) , Engine Controls Schematics (LUK)

Connector End View Reference

Throttle Actuator Control (TAC) System Description

Description and Operation

Electrical Information Reference

«Circuit Testing»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Ignition ON.
Verify DTC P0121, P0122, P0123, P0222, P0223, P0562, P0621, P0622, or P2135 is not set. If any of the DTCs are set Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) for further diagnosis. If none of the DTCs are set
Verify the scan tool Throttle Body Idle Airflow Compensation parameter is less than 90 %. 90 % or greater Refer to «Throttle Body Cleaning»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions__throttle-body-cleaning) . If less than 90 %
Clear the DTCs with a scan tool.
Ignition OFF and all vehicle systems OFF. It may take up to 2 minutes for all vehicle systems to power down.
Ignition ON.
Verify the scan tool TAC Motor parameter displays Enabled. If Disabled Refer to Circuit/System Testing If Enabled
Verify DTC P1516, P2101, P2119, or P2176 is not set. If any of the DTCs are set Refer to Circuit/System Testing If none of the DTCs are set
Verify the scan tool TAC Motor parameter displays Enabled while performing the Throttle Sweep Test with a scan tool. If Disabled NOTE: Before replacing the throttle body assembly, make sure the TAC motor control circuits are not shorted to B+. Test or replace the Q38 throttle body assembly. If Enabled
Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
Verify the DTC does not set. If the DTC sets Refer to Circuit/System Testing If the DTC does not set
All OK

Ignition OFF.
Verify the conditions listed below do not exist with the Q38 throttle body assembly: A throttle blade that is not in the rest position A throttle blade that is binding open or closed A throttle blade that is free to move open or closed without spring pressure If a condition is found Test or replace the Q38 throttle body assembly. If a condition is not found
Ignition OFF.
Disconnect the harness connector at the Q38 throttle body assembly, ignition ON.
Verify that a test lamp does not illuminate continuously between each motor control circuit listed below and ground. TAC Motor Control Open circuit terminal 1 TAC Motor Control Closed circuit terminal 2 If the test lamp illuminates continuously Ignition OFF, disconnect the harness connector at the K20 engine control module, ignition ON Test for less than 1 V between the control circuit and ground. If 1 V or greater, repair the short to voltage on the circuit. If the test lamp is always OFF
Verify that a test lamp does not illuminate between each motor control circuit listed below and B+. TAC Motor Control Open circuit terminal 1 TAC Motor Control Closed circuit terminal 2 If the test lamp illuminates Ignition OFF, disconnect the harness connector at the K20 engine control module. Test for infinite resistance between the control circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance, replace the K20 engine control module. If the test lamp is always OFF
Ignition OFF, set the DMM to the 40 V scale, select the Min/Max Recording Mode, and set the Peak Min/Max response time to 1 ms.
Verify the Max voltage is within 3 V of B+ while using DMM Min/Max Recording Mode function on each control circuit listed below as the ignition is turned ON. TAC Motor Control Open circuit terminal 1 TAC Motor Control Closed circuit terminal 2 If not within 3 V of B+ Ignition OFF, disconnect the harness connector at the K20 engine control module. Test for less than 2 ohms in the control circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K20 engine control module. If within 3 V of B+
Test or replace the Q38 throttle body assembly.

«Throttle Body Assembly Replacement»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions)
«Control Module References»(/buick/regal/v-2009-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, programming, and setup

Install any components that have been removed or replaced during diagnosis.
Perform any adjustments, programming or setup procedures that are required when a component is removed or replaced.
Clear the DTCs with a scan tool.
Ignition OFF and all vehicle systems OFF. It may take up to 2 minutes for all vehicle systems to power down.
Ignition ON.
Verify the scan tool TAC Motor parameter displays Enabled while performing the Throttle Sweep Test with a scan tool. If Disabled Test or replace the Q38 throttle body assembly. If Enabled
If the repair was related to a DTC, duplicate the Conditions for Running the DTC and use the Freeze Frame/Failure Records, if applicable, in order to verify the DTC does not reset. If any DTC sets Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) for further diagnosis. If no DTCs set
All OK

Perform the «Diagnostic System Check - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for a overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The hybrid powertrain control module is constantly sending serial data messages to the ECM regarding the operating state of the powertrain propulsion system. These messages are sent in a continuously repeating series of rolling counts with associated password protect samples and each count/sample is assigned a value. The ECM uses the values, during a propulsion system mode shift, to determine when and at what RPM to idle the internal combustion engine. When the ECM determines that too many of the counts/samples contain an error value, the ECM sets DTC P15F9.

DTC U1817 is not set.
The engine run time is greater than 0.5 s.
No other CAN errors are present.
The DTC runs continuously when the above conditions are met.

The ECM detects that 10 of 16 counts/samples contain an error value.

DTC P15F9 is a Type B DTC

DTC P15F9 is a Type B DTC.

An intermittent fault in the CAN circuits will cause the ECM to set DTC P15F9.

Description and Operation

Hybrid Modes of Operation Description

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

DTC P15F9 is an informational DTC. If there are no other engine control DTCs set, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) for diagnosis of hybrid powertrain control module DTCs.
Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Perform the «Diagnostic System Check - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

This diagnostic applies to internal microprocessor integrity conditions within the engine control module (ECM) or an out of range high pressure fuel pump actuator current.

DTCs P0016, P0017, P0090, P0091, P0092, P00C8, P00C9, P00CA, P0112, P0113, P0116, P0117, P0118, P0128, P0192, P0193, P0335, P0336, P0340, P0341, P0365, P0366, P0627-P0629, P1682 are not set.
The engine is running.
The ignition voltage is greater than 11 V.
The low side fuel pressure is greater than 275 kPa (40 psi).
DTC P163A runs continuously when the conditions are met for greater than 500 mS.

The ECM detects a condition with the integrated circuits of the high pressure fuel pump actuator driver module or the ECM detects that the current used to drive the high pressure fuel pump actuator is out of range for greater than 4 s.

DTC P163A is a Type B DTC.

Schematic Reference

Engine Controls Schematics (LEA) , Engine Controls Schematics (LUK)

Connector End View Reference

Engine Control Module Description

Description and Operation

Electrical Information Reference

«Circuit Testing»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Ignition OFF, disconnect the harness connector at the G18 high pressure fuel pump.
Test for 9-11 ohms at 25°C (77°F) between the low control circuit terminal 1 and the high control circuit terminal 2. If not within the specified range, replace the G18 high pressure fuel pump.
Measure the resistance between each terminal and the high pressure fuel pump housing. The DMM should display OL. If less than the specified value, replace the G18 high pressure fuel pump.
Ignition ON, verify that a test lamp does not illuminate between the high control circuit terminal 2 and ground and the low control circuit terminal 1 and ground. If the test lamp illuminates, test the appropriate control circuit for a short to voltage. If the circuit tests normal, replace the K20 ECM.
Verify that a test lamp does not illuminate between the high control circuit terminal 2 and B+ and the low control circuit terminal 1 and B+. If the test lamp illuminates, test the appropriate control circuit for a short to ground. If the circuit tests normal, replace the K20 ECM.
Connect a 3 A fused jumper wire between the high control circuit terminal 2 and ground. The Fuel Pressure Regulator High Control Circuit Open Test Status should transition from Malfunction to OK and the Fuel Pressure Regulator High Control Circuit Low Voltage Test Status should transition from OK to Malfunction. If not the specified value, test the high control circuit for an open/high resistance.
Connect a 3 A fused jumper wire between the low control circuit terminal 1 and B+. The Fuel Pressure Regulator Control Circuit Open Test Status should transition from Malfunction to OK and the Fuel Pressure Regulator Control Circuit High Voltage Test Status should transition from OK to Malfunction. If not the specified value, test the low control circuit for an open/high resistance.
If all circuits and the high pressure fuel pump test normal, replace the K20 ECM.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

«Fuel Pump Replacement»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions)
«Control Module References»(/buick/regal/v-2009-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for engine control module replacement, setup, and programming

Perform the «Diagnostic System Check - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Circuit Description

Fuel trim bias is used to keep the post catalyst air/fuel ratio within a predetermined range. This allows optimal catalyst efficiency under various operating conditions. The engine control module (ECM) constantly monitors how lean or rich the fuel trim bias is commanded, to determine if the fuel trim bias is greater than a calibrated amount.

DTC P0016, P0017, P0018, P0019, P0053, P0054, P0101, P0102, P0103, P0106, P0107, P0108, P0111, P0112, P0113, P0114, P0121, P0122, P0123, P0128, P0131, P0132, P0133, P0134, P0135, P0137, P0138, P013A, P013B, P013E, P013F, P0140, P0141, P0178, P0179, P0201, P0202, P0203, P0204, P0222, P0223, P0261, P0262, P0264, P0265, P0267, P0268, P0270, P0271, P0301, P0302, P0303, P0304, P0340, P0341, P0345, P0346, P0365, P0366, P0390, P0391, P0442, P0443, P0446, P0449, P0452, P0453, P0455, P1221, P1248, P1249, P124A, P124B, P2147, P2148, P2150, P2151, P2153, P2154, P2156, P2157, P219A, P2227, P2228, P2229, P2230, P2269, P2270, P2271, P2440, P2444, or P2A00 is not set.
The barometric pressure (BARO) is greater than 70 kPa (10.2 PSI).
The manifold absolute pressure (MAP) is between 0-200 kPa (0-29 PSI).
The intake air temperature (IAT) is between -20 and +200°C (-4 and +392°F).
The engine coolant temperature is greater than -20°C (-4°F).
The engine is in Closed Loop status.
The fuel control intrusive diagnostics are not active.
The engine is operating under light acceleration, heavy acceleration, deceleration, or cruise.
DTC P2096 runs continuously when the conditions above have been met for greater than 40 seconds.

The lean correction limit for a condition causing a rich air/fuel ratio has been exceeded.

DTCs P2096 is a Type B DTC.
The ECM records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the ECM stores this information in the Failure records. If the diagnostic reports a failure on the second ignition cycle, the ECM records the operating conditions at the time of the failure. The ECM writes the operating conditions to the Freeze Frame and updates the Failure records. The ECM illuminates the malfunction indicator lamp (MIL) when one of the following occurs: The ECM detects the same fuel trim failure during 2 consecutive trips. The ECM detects any fuel trim failure during any subsequent trip if the conditions at the time of failure meet the following criteria: The engine load is within 20 percent of the previous test that failed. The engine speed is within 375 RPM of the previous test that failed. The engine coolant temperature is in the same range of the previous test that failed.

DTCs P2096 is a Type B DTC.
The ECM turns OFF the malfunction indicator lamp (MIL) at the beginning of the fourth ignition cycle, after 3 ignition cycles that the diagnostic runs and does not fail.
A current DTC, Last Test Failed, clears when the diagnostic runs and passes.

It is very unlikely that an HO2S will cause this DTC to set without the occurrence of circuit related HO2S DTCs. Do not replace an HO2S to address this DTC without first performing all the steps in Circuit/System Verification.
The post catalyst fuel trim diagnostic is very sensitive to heated oxygen sensor (HO2S) design. A non-OE sensor or an incorrect part number may cause a DTC to set.
Certain aftermarket air filters may cause a DTC to set.
Certain aftermarket air induction systems or modifications to the air induction system may cause a DTC to set.
Certain aftermarket exhaust system components may cause a DTC to set.

Schematic Reference

Engine Controls Schematics (LEA) , Engine Controls Schematics (LUK)

Connector End View Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Ignition ON, observe the scan tool DTC information. Verify there is no other HO2S or fuel trim DTC set. If any other HO2S or fuel trim DTC is set, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) .
Verify that none of the following conditions exist: The air intake duct for being collapsed or restricted. The air filter for biting dirty or restricted. Objects blocking the throttle body. Excessive fuel in the crankcase. Change engine oil as necessary. Rich fuel injectors-Refer to «Fuel Injector Solenoid Coil Test»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-dtc-p0411-luk-to-dtc-p2635-and-symptom-troubleshooting-diagnosis) . Excessive fuel system pressure-Refer to «Fuel System Diagnosis»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-dtc-p0411-luk-to-dtc-p2635-and-symptom-troubleshooting-diagnosis) . Fuel that is contaminated-Refer to «Alcohol/Contaminants-in-Fuel Diagnosis»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-dtc-p0411-luk-to-dtc-p2635-and-symptom-troubleshooting-diagnosis) . Fuel saturation of the evaporative emissions (EVAP) canister Stuck open or leaking EVAP purge valve Restricted exhaust-Refer to «Symptoms - Engine Exhaust»(/buick/regal/v-2009-2013/remont/exhaust/#engine-exhaust-system__symptoms-engine-exhaust) Incorrect PCV system operation-Refer to «Crankcase Ventilation System Inspection/Diagnosis (Without Turbocharger)»(/buick/regal/v-2009-2013/remont/mechanical/#engine-mechanical-24l__crankcase-ventilation-system-inspectiondiagnosis-without-tur) If you find any of the above conditions, repair as necessary.
Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Perform the «Diagnostic System Check - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

DTC P0016, P0017, P0018, P0019, P0053, P0054, P0101, P0102, P0103, P0106, P0107, P0108, P0111, P0112, P0113, P0114, P0121, P0122, P0123, P0128, P0131, P0132, P0133, P0134, P0135, P0137, P0138, P013A, P013B, P013E, P013F, P0140, P0141, P0178, P0179, P0201, P0202, P0203, P0204, P0222, P0223, P0261, P0262, P0264, P0265, P0267, P0268, P0270, P0271, P0301, P0302, P0303, P0304, P0340, P0341, P0345, P0346, P0365, P0366, P0390, P0391, P0442, P0443, P0446, P0449, P0452, P0453, P0455, P1221, P1248, P1249, P124A, P124B, P2147, P2148, P2150, P2151, P2153, P2154, P2156, P2157, P219A, P2227, P2228, P2229, P2230, P2269, P2270, P2271, P2440, P2444, or P2A00 is not set.
The barometric pressure (BARO) is greater than 70 kPa (10.2 PSI).
The manifold absolute pressure (MAP) is between 0-200 kPa (0-29 PSI).
The intake air temperature (IAT) is between -20 and +200°C (-4 and +392°F).
The engine coolant temperature is greater than -20°C (-4°F).
The engine is in Closed Loop status.
The fuel control intrusive diagnostics are not active.
The engine is operating under light acceleration, heavy acceleration, deceleration, or cruise.
DTC P2097 runs continuously when the conditions above have been met for greater than 40 seconds.

The rich correction limit for a condition causing a lean air/fuel ratio has been exceeded.

DTCs P2097 is a Type B DTC.
The ECM records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the ECM stores this information in the Failure records. If the diagnostic reports a failure on the second ignition cycle, the ECM records the operating conditions at the time of the failure. The ECM writes the operating conditions to the Freeze Frame and updates the Failure records. The ECM illuminates the malfunction indicator lamp (MIL) when one of the following occurs: The ECM detects the same fuel trim failure during 2 consecutive trips. The ECM detects any fuel trim failure during any subsequent trip if the conditions at the time of failure meet the following criteria: The engine load is within 20 percent of the previous test that failed. The engine speed is within 375 RPM of the previous test that failed. The engine coolant temperature is in the same range of the previous test that failed.

DTCs P2097 is a Type B DTC.
The ECM turns OFF the malfunction indicator lamp (MIL) at the beginning of the fourth ignition cycle, after 3 ignition cycles that the diagnostic runs and does not fail.
A current DTC, Last Test Failed, clears when the diagnostic runs and passes.

It is very unlikely that an HO2S will cause this DTC to set without the occurrence of circuit related HO2S DTCs. Do not replace an HO2S to address this DTC without first performing all the steps in Circuit/System Verification.
The post catalyst fuel trim diagnostic is very sensitive to heated oxygen sensor (HO2S) design. A non-OE sensor or an incorrect part number may cause a DTC to set.
An exhaust system leak that may not be audible can set this DTC.
Certain aftermarket air filters may cause a DTC to set.
Certain aftermarket air induction systems or modifications to the air induction system may cause a DTC to set.
Certain aftermarket exhaust system components may cause a DTC to set.

Schematic Reference

Engine Controls Schematics (LEA) , Engine Controls Schematics (LUK)

Connector End View Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Ignition ON, observe the scan tool DTC information. Verify there is no other HO2S or fuel trim DTC set. If any other HO2S or fuel trim DTC is set, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) .
Verify that none of the following conditions exist: Exhaust system leaks-Refer to «Symptoms - Engine Exhaust»(/buick/regal/v-2009-2013/remont/exhaust/#engine-exhaust-system__symptoms-engine-exhaust) Vacuum hoses for splits, kinks, and proper connections Insufficient fuel in the tank The air induction system and the air intake ducts for leaks or for a missing air filter element A cracked evaporative canister Evaporative pipes plugged, obstructed, or leaking The crankcase ventilation system for leaks. Refer to «Crankcase Ventilation System Inspection/Diagnosis (Without Turbocharger)»(/buick/regal/v-2009-2013/remont/mechanical/#engine-mechanical-24l__crankcase-ventilation-system-inspectiondiagnosis-without-tur) Engine vacuum leaks Low fuel system pressure-Refer to «Fuel System Diagnosis»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-dtc-p0411-luk-to-dtc-p2635-and-symptom-troubleshooting-diagnosis) . Fuel that is contaminated-Refer to «Alcohol/Contaminants-in-Fuel Diagnosis»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-dtc-p0411-luk-to-dtc-p2635-and-symptom-troubleshooting-diagnosis) . Lean fuel injectors-Refer to «Fuel Injector Solenoid Coil Test»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-dtc-p0411-luk-to-dtc-p2635-and-symptom-troubleshooting-diagnosis) . If you find any of the above conditions, repair as necessary.
Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Perform the «Diagnostic System Check - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Circuit	Short to Ground	High Resistance	Open	Short to Voltage	Signal Performance
Accelerator Pedal Position (APP) Sensor 1 5 V Reference Circuit	P06A3	P2138	P2122	P06A3	P2138
Accelerator Pedal Position (APP) Sensor 2 5 V Reference Circuit	P0108, P0107, P0697	P2138	P2127	P0106, P0108, P0697	P2138
Accelerator Pedal Position (APP) Sensor 1 Signal	P2122	P2138	P2122	P2123, P2138	P2138
Accelerator Pedal Position (APP) Sensor 2 Signal	P2127	P2138	P2127	P2128, P2138	P2138
Accelerator Pedal Position (APP) Sensor 1 Low Reference		P2138	P2123		P2138
Accelerator Pedal Position (APP) Sensor 2 Low Reference		P2138	P2128		P2138

Circuit	Short to Ground	Open	Short to Voltage
Operating Conditions: The engine is operating at idle. Parameter Normal Range: APP Sensor 1 0.88-1.08 V
APP Sensor 1 5 V Reference	0.00 V	0.00 V	2-5 V
APP Sensor 1 Signal	0.00 V	0.00 V	4-5 V
APP Sensor 1 Low Reference		4-5 V

APP Sensor 1

Circuit	Short to Ground	Open	Short to Voltage
Operating Conditions: The engine is operating at idle. Parameter Normal Range: APP Sensor 2 0.39-0.59 V
APP Sensor 2 5 V Reference	0.00 V	0.00 V	1-2 V
APP Sensor 2 Signal	0.00 V	0.00 V	2-5 V
APP Sensor 2 Low Reference		4-5 V

APP Sensor 2

The accelerator pedal assembly contains 2 accelerator pedal position (APP) sensors. The APP sensors are mounted to the accelerator pedal assembly and are not serviceable. The APP sensors provide a signal voltage that changes relative to pedal position. The engine control module (ECM) supplies each APP sensor with a 5 V reference circuit, a low reference circuit, and a signal circuit.

Both the APP sensors 1 and 2 signal percentages increase as the pedal is depressed, from approximately 0 percent at rest to above 95 percent when fully depressed.

P2122, P2123, P2127, or P2128

DTC P06A3 or P0697 are not set.
The ignition is ON or the engine is operating.
The ignition voltage is greater than 6 V.
The ECM is not commanding reduced power.
The DTCs run continuously when the above conditions are met.

P2138

DTCs P06A3, P0697, P2122, P2123, P2127, or P2128 are not set.
The ignition is ON or the engine is operating.
The ignition voltage is greater than 6 V.
The ECM is not commanding reduced power.
The DTC runs continuously when the above conditions are met.

P2122

The ECM detects that the APP sensor 1 voltage is less than 0.46 V for greater than 1 s.

P2123

The ECM detects that the APP sensor 1 voltage is greater than 4.7 V for greater than 1 s.

P2127

The ECM detects that the APP sensor 2 voltage is less than 0.32 V for greater than 1 s.

P2128

The ECM detects that the APP sensor 2 voltage is greater than 2.6 V for greater than 1 s.

P2138

The ECM detects that APP sensor 1 and APP sensor 2 disagree greater than 10 percent for greater than 1 s.

The ECM detects that both APP sensor 1 and APP sensor 2 are 5 percent greater than the learned minimum position for greater than 1 s.

DTCs P2122, P2123, P2127, P2128, and P2138 are type A DTCs.
The ECM commands the TAC system to operate in a Reduced Engine Power mode.

DTCs P2122, P2123, P2127, P2128, and P2138 are type A DTCs.

A high resistance condition on the accelerator pedal position circuits could cause a DTC to set.
Ensure that the in-line harness connector seals are installed correctly. Improper installation could result in water intrusion into the connector and cause a DTC to set.

Schematic Reference

Engine Controls Schematics (LEA) , Engine Controls Schematics (LUK)

Connector End View Reference

Throttle Actuator Control (TAC) System Description

Description and Operation

Electrical Information Reference

«Circuit Testing»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Ignition ON.
Verify DTC P0697 or P06A3 is not set. If any of the DTCs are set Refer to «DTC P0641, P0651, P0697, or P06A3 (ECM)»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-dtc-p0411-luk-to-dtc-p2635-and-symptom-troubleshooting-diagnosis) for further diagnosis. If none of the DTCs are set
Verify the APP Sensor 1 Circuit Status and APP Sensor 2 Circuit Status displays OK. If Malfunction is displayed Refer to Circuit/System Testing If OK is displayed
Verify the scan tool APP Sensor 1 and 2 Agree/Disagree parameter displays Agree while performing the tests listed below: Rapidly depress the accelerator pedal from the rest position to the wide open throttle position (WOT) and release pedal. Repeat the procedure several times. Slowly depress the accelerator pedal to WOT and then slowly return the pedal to closed throttle. Repeat the procedure several times. If Disagree Refer to Circuit/System Testing If Agree
Verify that DTC P2122, P2123, P2127, P2128, or P2138 is not set. If any of the DTCs are set Refer to Circuit/System Testing If none of the DTCs set
Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
Verify the DTC does not set. If the DTC sets Refer to Circuit/System Testing If the DTC does not set
All OK

Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the B107 accelerator pedal assembly. It may take up to 2 minutes for all vehicle systems to power down.
Test for less than 5 ohms between each low reference circuit terminal listed below and ground. Low reference circuit terminal 4 or A Low reference circuit terminal 5 or D If 5 ohms or greater Ignition OFF, disconnect the harness connector at the K20 engine control module. Test for less than 2 ohms in the low reference circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K20 engine control module. If less than 5 ohms
Ignition ON.
Test for 4.8-5.2 V between each 5 V reference circuit terminal listed below and ground. 5 V reference circuit terminal 1 or C 5 V reference circuit terminal 2 or F If less than 4.8 V Ignition OFF, disconnect the harness connector at the K20 engine control module. Test for infinite resistance between the 5 V reference circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in the 5 V reference circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K20 engine control module. If greater than 5.2 V Ignition OFF, disconnect the harness connector at the K20 engine control module, ignition ON. Test for less than 1 V between the 5 V reference circuit and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the K20 engine control module. If between 4.8-5.2 V
Verify each APP sensor voltage parameter is less than 0.2 V. If 0.2 V or greater Ignition OFF, disconnect the harness connector at the K20 engine control module, ignition ON. Test for less than 1 V between the signal circuit terminal listed below and ground. APP sensor 1 signal circuit terminal 3 or E APP sensor 2 signal circuit terminal 6 or B If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the K20 engine control module. If less than 0.2 V
Install a 3 A fused jumper wire between each signal circuit terminal listed below and the 5 V reference circuit terminal 1 or C. APP sensor 1 signal circuit terminal 3 or E APP sensor 2 signal circuit terminal 6 or B
Verify the scan tool APP sensor voltage parameter is greater than 4.8 V. If 4.8 V or less Ignition OFF, disconnect the harness connector at the K20 engine control module. Test for infinite resistance between the signal circuit terminal and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in the signal circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K20 engine control module. If greater than 4.8 V
Test or replace the B107 accelerator pedal assembly.

Perform the Diagnostic Repair Verification after completing the repair.

«Accelerator Pedal with Position Sensor Assembly Replacement»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions)
«Control Module References»(/buick/regal/v-2009-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, programming, and setup

Perform the «Diagnostic System Check - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
IAT Sensor 1 Signal	P0112, P0114, P2199	P0111, P0113, P0114, P2199	P0113*, P0114, P2199	P0111, P2199
Low Reference		P0111, P0113, P0114, P2199	P0113*, P0114
*Internal ECM or sensor damage may occur if the circuit is shorted to B+.

IAT Sensor 1

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
Ignition 1 Voltage	P0096, P0097, P11C3, P2199	P0096, P0097, P0102, P11C2, P2199		P0096
IAT Sensor 2 Signal	P0096, P0097, P0102, P11C2, P2199	P0096, P0097, P11C2, P2199	P0096*, P0097, P11C2, P2199	P0096
Ground		P0096, P0097, P0102, P11C2, P2199		P0096
*Internal ECM or sensor damage may occur if the circuit is shorted to B+.

IAT Sensor 2

Circuit	Short to Ground	Open or High Resistance	Short to Voltage
Operating Conditions: Engine Running Parameter Normal Range: Varies with ambient temperature; and engine bay conditions
IAT Sensor 1 Signal	150°C (302°F)	40°C (-40°F)	40°C (-40°F)*
Low Reference		40°C (-40°F)	40°C (-40°F)*
*Internal ECM or sensor damage may occur if the circuit is shorted to B+

IAT Sensor 1

Circuit	Short to Ground	Open or High Resistance	Short to Voltage
Operating Conditions: Engine Running Parameter Normal Range: Varies with ambient humidity and temperature; and engine bay conditions
Ignition 1	40°C (-40°F)	40°C (-40°F)
IAT Sensor 2 Signal	40°C (-40°F)	40°C (-40°F)	40°C (-40°F)*
Ground		40°C (-40°F)
*Internal ECM or sensor damage may occur if the circuit is shorted to B+

IAT Sensor 2

Circuit	Short to Ground	Open or High Resistance	Short to Voltage
Operating Conditions: Engine Running Parameter Normal Range: Varies with coolant temperature
ECT Sensor Signal	150°C (302°F)	40°C (-40°F)	40°C (-40°F)*
Low Reference		40°C (-40°F)	40°C (-40°F)*
*Internal ECM or sensor damage may occur if the circuit is shorted to B+

ECT Sensor

The intake air temperature (IAT) sensor 1 is a variable resistor that measures the temperature of the air in the sensor bore. The engine control module (ECM) supplies 5 V to the IAT sensor 1 signal circuit and a ground for the IAT sensor 1 low reference circuit. The signal varies with inlet air temperature and is displayed by the scan tool as °C (°F).

The IAT sensor 2 produces a frequency signal based on the inlet air temperature very close to the humidity sensor within the sensor bore. The signal varies with inlet air temperature and is displayed by the scan tool as °C (°F) and Hertz (Hz). The ECM applies 5 V to the circuit. The signal circuit is shared by the IAT sensor 2 and the humidity sensor. Ignition voltage and ground circuits are also supplied to the multifunction intake air sensor's internal circuits for these sensors

IAT sensor 2
Humidity sensor
MAF sensor

The multifunction intake air sensor houses the following

IAT sensor 1
IAT sensor 2
Humidity sensor
MAF sensor
BARO pressure sensor

IAT Sensor 1	IAT Sensor 1 Resistance	IAT Sensor 1 Signal Voltage
Cold	High	High
Warm	Low	Low

IAT Sensor 2	IAT Sensor 2 Frequency	IAT Sensor 2 Temperature
Cold	45 Hz	40°C (-40°F)
Warm	302 Hz	104°C (219°F)

The ignition is ON.
Ignition 1 voltage is at least 11 V for at least 0.9 s.
This DTC runs continuously within the enabling conditions.

The ECM detects that the absolute difference between the IAT sensor 1 and the IAT sensor 2 temperatures is greater than 55°C (99°F) for longer than 5 s.

DTC P2199 is a Type B DTC.

With the ignition ON, the engine OFF, if the engine is cold, a properly functioning IAT sensor 2 will gradually increase the scan tool IAT Sensor 2 parameter. This is due to the heat that is generated by the multifunction intake air sensor heating elements.
Depending on the ambient temperature, an IAT sensor 1 signal circuit that is shorted to the MAF sensor signal circuit can cause either a rapid fluctuation in the IAT Sensor 1 parameter or cause it to become stuck at a given value.
An IAT sensor 1 low reference circuit that is open can cause the IAT Sensor 1 parameter response to be sluggish.
The humidity sensor and the IAT sensor 2 signals are sent to the ECM on the same circuit. If the IAT Sensor 2 parameter displays the values: 10 Hz; -40°C (-40°F), and there are Humidity Sensor DTCs, check for a circuit problem.

Schematic Reference

Engine Controls Schematics (LEA) , Engine Controls Schematics (LUK) Engine Controls Schematics

Connector End View Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References Control Module References for scan tool information

Special Tools

J 38522 Variable Signal Generator

For equivalent regional tools, refer to Special Tools (Diagnostic Tools) .

Note. Perform Step 1 of this verification procedure only if the ignition has been OFF for 8 hours or more.

Ignition ON, observe the following scan tool parameters. The readings should be within 30°C (54°F) of each other. Start-Up IAT Sensor 1 IAT Sensor 2 Start-Up ECT
Engine running, observe the scan tool IAT Sensor 1 and IAT Sensor 2 parameters. Depending on the current ambient temperature, engine bay conditions, and the vehicle operating conditions, the readings should be between: -38 and +149°C (-36 and +300°F) for IAT Sensor 1 -38 and +149°C (-36 and +300°F) for IAT sensor 2
Operate the vehicle within the conditions for running the DTC to verify that the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the freeze frame/failure records data.

Ignition OFF, disconnect the harness connector at the B75C multifunction intake air sensor.
Ignition OFF, all systems OFF. It may take up to for 2 minutes for all vehicle systems to power down. Test for less than 5 ohms between the low reference circuit terminal 3 and ground. If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the K20 engine control module.
Ignition OFF, all vehicle systems OFF, test for less than 5 ohms between the ground circuit terminal 7 and ground. If greater than the specified range, test the ground circuit for an open/high resistance.
Ignition ON, verify the scan tool IAT Sensor 1 parameter is colder than -39°C (-38°F). If warmer than the specified range, test the signal circuit for a short to ground. If the circuit tests normal, replace the K20 engine control module.
Install a 3 A fused jumper wire between the signal circuit terminal 1 and ground. Verify the scan tool IAT Sensor 1 parameter is warmer than 149°C (300°F). If colder than the specified range, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the K20 engine control module.
Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal 5 and ground. If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance. If the circuit tests normal and the fuse is open, test all the components connected to the circuit and repair or replace as necessary.
Ignition ON, test for 4.8-5.2 V between the IAT sensor 2 signal circuit terminal 8 and ground. If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K20 engine control module. NOTE: If the signal circuit is shorted to a voltage the engine control module or the sensor may be damaged. If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the K20 engine control module.
Ignition OFF, connect the red lead of the «J 38522»(/buick/regal/v-2009-2013/remont/automatic-trans/#automatic-transmission-6t406t456t50-special-tools-and-equipment) to the signal circuit terminal 8 at the harness connector. Connect the battery voltage supply to B+, and the black lead to ground.
Set the «J 38522»(/buick/regal/v-2009-2013/remont/automatic-trans/#automatic-transmission-6t406t456t50-special-tools-and-equipment) to the following specifications. Signal switch to 5 V Duty Cycle switch to 50 % (Normal) Frequency switch to 30 Hz
Ignition ON, observe the scan tool IAT Sensor 2 parameter. The scan tool parameter should be between 28-32 Hz. If the parameter is not within the specified range, replace the K20 engine control module.
If all circuits test normal, test or replace the B75C multifunction intake air sensor.

Ignition OFF, disconnect the harness connector at the B75C multifunction intake air sensor.
Test the IAT sensor 1 by varying the sensor temperature while monitoring the sensor resistance. Compare the readings with the «Temperature Versus Resistance - Intake Air Temperature Sensor (Hitatchi Sensor)»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-specifications__temperature-versus-resistance-intake-air) table. The resistance values should be in range of the table values. If not within the specified range, replace the B75C multifunction intake air sensor.

Perform the Diagnostic Repair Verification after completing the repair.

«Mass Airflow Sensor with Intake Air Temperature Sensor Replacement»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions) for multifunction intake air sensor replacement.
«Control Module References»(/buick/regal/v-2009-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for engine control module replacement, programming, and setup

Perform the «Diagnostic System Check - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The Air Fuel Imbalance diagnostic detects a rich or lean cylinder to cylinder air/fuel ratio imbalance. The diagnostic monitors the pre-catalyst heated oxygen sensor (HO2S) signal's frequency and amplitude characteristics by calculating an accumulated voltage over a predetermined sample period. An imbalance is indicated when multiple samples of the accumulated voltage are consistently higher than the desired value.

DTCs P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0116, P0117, P0118, P0122, P0123, P0128, P0201-P0204, P0261, P0262, P0264, P0265, P0267, P0268, P0270, P0271, P0300, P0301-P0304, P0411, P0442, P0443, P0455, P0496, P1248, P1249, P124A, P124B, P2101, P2135, P2147, P2148, P2150. P2151, P2153, P2154, P2156, P2157, P2440, P2444 are not set.
The device control is not active.
The intrusive diagnostics are not active.
The engine overspeed protection is not active.
The engine is in closed loop status.
The system voltage is greater than 11 V for greater than 2 s.
The engine coolant temperature (ECT) is warmer than -20°C (-4°F).
The engine speed is between 900-4, 200 RPM.
The mass air flow is between 7-200 g/s.
The AIR pump is not ON.
Engine run time is greater than 30 s.
Fuel level is greater than 10% and no fuel level sensor fault is present.
The DTC runs continuously when the above conditions have been met.

Multiple samples of the pre-catalyst HO2S accumulated voltage are consistently greater than the desired value.

DTC P219A is a Type A DTC.

The air fuel imbalance diagnostic is very sensitive to heated oxygen sensor (HO2S) design. A non-OE sensor or an incorrect part number may cause a DTC to set.
Monitoring the misfire current counters, or misfire graph, may help to isolate the cylinder that is causing the condition.
Certain aftermarket air filters may cause a DTC to set.
Certain aftermarket air induction systems or modifications to the air induction system may cause a DTC to set.
Certain aftermarket exhaust system components may cause a DTC to set.

Schematic Reference

Engine Controls Schematics (LEA) , Engine Controls Schematics (LUK)

Connector End View Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Troubleshooting with a Test Lamp»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__troubleshooting-with-a-test-lamp)
«Testing for Intermittent Conditions and Poor Connections»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)
«Connector Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Read and record the Freeze Frame/Failure Records data taking note of the speed and load at which the DTC set.
Diagnose any other DTCs that are set. Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) .
With the engine idling and the transmission in the Park or Neutral position, observe the manifold absolute pressure (MAP) sensor parameter. The MAP sensor parameter should be between 20-48 kPa. If the MAP sensor parameter is not between 20-48 kPa, refer to «DTC P0106»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-dtc-p0010-to-dtc-p0411) .
Inspect the air induction system for modified, damaged, leaking, or restricted components.
Inspect the crankcase ventilation system for improper operation. Refer to «Crankcase Ventilation System Inspection/Diagnosis (Without Turbocharger)»(/buick/regal/v-2009-2013/remont/mechanical/#engine-mechanical-24l__crankcase-ventilation-system-inspectiondiagnosis-without-tur) .
Inspect the vacuum hoses for splits, kinks, and improper connections.
Test for a restricted, damaged, leaking, or modified exhaust system from the catalytic converter forward. Refer to «Symptoms - Engine Exhaust»(/buick/regal/v-2009-2013/remont/exhaust/#engine-exhaust-system__symptoms-engine-exhaust) .
Test the fuel injectors for improper operation. Refer to «Fuel Injector Solenoid Coil Test»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-dtc-p0411-luk-to-dtc-p2635-and-symptom-troubleshooting-diagnosis) .
Test for fuel contamination. Refer to «Alcohol/Contaminants-in-Fuel Diagnosis»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-dtc-p0411-luk-to-dtc-p2635-and-symptom-troubleshooting-diagnosis) .
Test for excessive fuel in the crankcase due to leaking injectors. Change engine oil as necessary.
Test the ignition system for improper operation. Refer to «Electronic Ignition System Diagnosis»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-dtc-p0411-luk-to-dtc-p2635-and-symptom-troubleshooting-diagnosis) .
Test the engine for any mechanical conditions such as sticking valves, lifters, etc., which could alter the flow into the combustion chamber. Refer to «Symptoms - Engine Mechanical»(/buick/regal/v-2009-2013/remont/mechanical/#engine-mechanical-24l) .

Perform the Diagnostic Repair Verification after completing the diagnostic procedure. Verify the repair under the same speed and load as noted in the Freeze Frame/Failure Records data recorded during testing.

Perform the «Diagnostic System Check - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
5 V Reference	P0641, P2227, P2228	P2228	P0641, P2229	P2227
Signal	P2227, P2228	P2227, P2228	P2227, P2229	P2227
Low Reference		P2227, P2229		P2227

Circuit	Short to Ground	Open	Short to Voltage
Operating Conditions: Ignition ON, Engine OFF Parameter Normal Range: 56-105 kPa (8.1-15.2 psi), varies with altitude
5 V Reference	0 kPa (0 psi)	0 kPa (0 psi)	127 kPa (18.4 psi)
Signal	0 kPa (0 psi)	0 kPa (0 psi)	127 kPa (18.4 psi)
Low Reference		127 kPa (18.4 psi)

BARO

The barometric pressure (BARO) sensor is integral to the multifunction intake air sensor and responds to changes in altitude and atmospheric conditions. This gives the engine control module (ECM) an indication of barometric pressure. The ECM uses this information to calculate fuel delivery. The BARO sensor provides a voltage signal to the ECM relative to the atmospheric pressure changes. The ECM monitors the BARO sensor signal for a voltage outside of the normal range.

P2227

DTC P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0117, P0118, P0121, P0122, P0123, P0222, P0223, P1516, P2135, P2228, or P2229 is not set.
The engine is running. OR
DTC P0106, P0107, P0108, P2228, P2229, or P2230 is not set and not pending.
Ignition ON, engine OFF
DTC P2227 runs continuously when the above conditions are met.

P2228 or P2229

The engine is running.
The DTCs run continuously when the above condition is met.

P2230

DTC P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0117, P0118, P0121, P0122, P0123, P0222, P0223, P1516, P2135, P2228, or P2229 is not set.
The engine is running.
DTC P2230 runs continuously when the above conditions are met.

P2227

The engine is running.
The ECM detects that the difference between the BARO signal and the calculated BARO is greater than 15 kPa (2.2 psi) if the vehicle has traveled at most 0.5 km (0.31 mi) since the last calculated BARO update, or the ECM detects that the difference between the BARO signal and the calculated BARO is greater than 25 kPa (3.6 psi) if the vehicle has traveled greater than 0.5 km (0.31 mi) since the last calculated BARO update. OR
Ignition ON, engine OFF
The ECM detects that the BARO pressure is less than 50 kPa (7.3 psi) or greater than 115 kPa (16.7 psi).

P2228

The ECM detects that the BARO sensor voltage is less than 1.95 V for greater than 4 s.

P2229

The ECM detects that the BARO sensor voltage is greater than 4.5 V for greater than 4 s.

P2230

The ECM detects that the difference between the current BARO sensor reading and the previous BARO sensor reading is greater than 10 kPa (1.5 psi).

DTCs P2227, P2228, P2229, and P2230 are Type B DTCs.

Inspect the inlet port on the BARO sensor for moisture or debris and attempt to dry or clean the inlet, if contaminated.

Schematic Reference

Engine Controls Schematics (LEA) , Engine Controls Schematics (LUK)

Connector End View Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Ignition ON, observe the DTC information with a scan tool. Verify that DTC P0641 is not set. If a DTC is set, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) for further diagnosis.
Ignition ON, observe the scan tool BARO parameter. Compare the parameter to the «Altitude Versus Barometric Pressure»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-specifications__altitude-versus-barometric-pressure) table. The BARO parameter should be within the specified range indicated in the table.
Engine running observe the DTC information with a scan tool. DTC P2227, P2228, P2229, or P2230 should not set.
Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Ignition OFF, disconnect the harness connector at the B75C multifunction intake air sensor.
Ignition OFF and all vehicle systems OFF. It may take up to 2 minutes for all vehicle systems to power down. Test for less than 5 ohms between the low reference circuit terminal 3 and ground. If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the K20 engine control module.
Ignition ON, test for 4.8-5.2 V between the 5 V reference circuit terminal 2 and ground. If less than the specified range, test the 5 V reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K20 engine control module. If greater than the specified range, test the 5 V reference circuit for a short to voltage. If the circuit tests normal, replace the K20 engine control module.
Verify the scan tool BARO parameter is less than 1 kPa (0.2 psi). If greater than the specified range, test the signal circuit terminal 4 for a short to voltage. If the circuit tests normal, replace the K20 engine control module.
Install a 3 A fused jumper wire between the signal circuit terminal 4 and the 5 V reference circuit terminal 2. Verify the scan tool BARO parameter is greater than 127 kPa (18.4 psi). If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K20 engine control module.
If the circuits test normal, replace the B75C multifunction intake air sensor.

Perform the Diagnostic Repair Verification after completing the repair.

«Mass Airflow Sensor with Intake Air Temperature Sensor Replacement»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions) for multifunction intake air sensor replacement
«Control Module References»(/buick/regal/v-2009-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for engine control module replacement, programming, and setup.

Perform the «Diagnostic System Check - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Alcohol content information is supplied to the ECM from the fuel composition sensor. The fuel composition sensor has a battery positive circuit, a signal circuit, and a ground circuit. The fuel composition sensor uses a microprocessor inside the sensor to measure the ethanol percentage and changes the output signal accordingly. The signal circuit carries the ethanol percentage via the frequency signal. The ECM provides an internal pull up to 5 V on the signal circuit, and the fuel composition sensor pulls the 5 V to ground in pulses. The normal range of operating frequency is between 50-150 Hz. The microprocessor inside the sensor is capable of a certain amount of self-diagnosis. An output frequency between 180 Hz and 190 Hz indicates that the fuel is contaminated.

The ignition voltage is greater than 11 V.
The DTC runs continuously when the above condition is met.

The ECM detects that the fuel composition sensor output frequency is greater than 185 Hz for greater than 6 s.

DTC P2269 is a Type B DTC.

A momentary slug of water in the fuel system may set this DTC.

Schematic Reference

Engine Controls Schematics (LEA) , Engine Controls Schematics (LUK)

Connector End View Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Special Tools

J 38522 Variable Signal Generator
J 44175-A Fuel Composition Tester

Engine running, verify the scan tool Fuel Composition Sensor parameter is between 50-150 Hz.
Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Verify that there are no contaminants, water, or too high of a concentration of ethanol in the fuel. Refer to «Alcohol/Contaminants-in-Fuel Diagnosis»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-dtc-p0411-luk-to-dtc-p2635-and-symptom-troubleshooting-diagnosis) and the J 44175-A Instruction Manual.
Ignition OFF, disconnect the harness connector at the B198 fuel composition sensor.
Ignition OFF and all vehicle systems OFF. It may take up to 2 minutes for all vehicle systems to power down. Test for less than 5 ohms between the ground circuit terminal 2 and ground. If greater than the specified range, test the ground circuit for an open/high resistance.
Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal 1 and ground. If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit tests normal and the fuse is open, test all the components connected to the circuit, and repair or replace as necessary.
Ignition ON, test for 4.8-5.2 V between the signal circuit terminal 3 and ground. If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K20 ECM. If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the K20 ECM.
Ignition OFF, connect the red lead of the J 38522 Variable Signal Generator to the signal circuit terminal 3 at the B198 fuel composition sensor harness connector. Connect the battery voltage supply to B+, and the black lead to ground.
Set the J 38522 Variable Signal Generator Signal to 5 V, the Frequency to 60 Hz, and the Duty Cycle to Normal.
Ignition ON, verify the scan tool Fuel Composition Sensor parameter is at 60 Hz. If not at the specified value, replace the K20 ECM.
If all circuits test normal, test or replace the B198 fuel composition sensor.

Test the fuel composition using the J 44175-A Fuel Composition Tester and the J 44175-A Instruction Manual. Record the frequency.
Compare the special tool test frequency and the scan tool Fuel Composition Sensor frequency parameter. The difference between the tool and the sensor should be less than 12 Hz. If greater than the specified value, replace the B198 fuel composition sensor.

Perform the Diagnostic Repair Verification after completing the repair.

«Fuel System Cleaning»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions__fuel-system-cleaning)
«Control Module References»(/buick/regal/v-2009-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, setup, and programming

Perform the «Diagnostic System Check - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
5 V Reference	P0651, P2432	P2431	P0651, P2431	P2430, P2431
Secondary Air Injection Pressure Sensor Signal	P2432	P2432	P2433	P2430, P2431
Low Reference		P2433		P2430, P2431

Circuit	Short to Ground	Open	Short to Voltage
Parameter Normal Range: BARO Operating Conditions: Engine running under various operating conditions
5 V Reference	41 kPa (5.9 psi)	41 kPa (5.9 psi)	111 kPa (16.1 psi)
AIR Pressure Sensor Signal	42 kPa (6.1 psi)	41 kPa (5.9 psi)	150 kPa (21.8 psi)
Low Reference		145 kPa (21 psi)

Secondary Air Injection Pressure Sensor

The secondary air injection system aids in the reduction of hydrocarbon emissions during a cold start. The electric air pump forces fresh air into the exhaust stream in order to accelerate the catalyst operation. A secondary air injection pressure sensor is used to monitor the air flow from the secondary air injection pump. The Engine Control Module (ECM) supplies voltage to the 5 V reference circuit and provides a ground for the low reference circuit. The sensor provides a signal voltage to the ECM relative to the pressure changes within the secondary air injection system.

DTC P2430

DTC P0412, P0418, P0606, P0641, P0651, P2432, or P2433 is not set.
Greater than 30 min has elapsed since the last cold start.
The barometric pressure (BARO) is greater than 60 kPa (8.7 psi).
The intake air temperature (IAT) is greater than -11°C (12°F).
The engine coolant temperature (ECT) is between -11 to +60°C (12-140°F).
The ignition voltage is between 10-32 V.
The manifold absolute pressure (MAP) sensor is greater than 20 kPa (2.9 psi).
The engine speed is less than 5, 000 RPM.
The mass air flow (MAF) is less than 50 g/s.
The AIR pump is commanded ON.
DTC P2430 runs continuously when the above conditions are met.

DTC P2431

DTC P0101, P0102, P0103, P0300, P0301, P0302, P0304, P0412, P0418, P0606, P0641, P0651, P2432, or P2433 is not set.
The barometric pressure (BARO) is greater than 60 kPa (8.7 psi).
The intake air temperature (IAT) is greater than -11°C (12°F).
The engine coolant temperature (ECT) is between -11 to +60°C (12-140°F).
The ignition voltage is between 10-32 V.
The manifold absolute pressure (MAP) sensor is greater than 20 kPa (2.9 psi).
Run/Crank is not active.
The engine speed is less than 5, 000 RPM.
The mass air flow (MAF) is less than 50 g/s.
Greater than 30 minutes has elapsed since the last cold start.
DTC P2431 runs continuously when the above conditions are met.

P2432 and P2433

DTC P0606, P0641, or P0651 is not set.
The ignition is ON or the engine is running.
DTC P2432 and P2433 run continuously when the above conditions are met.

P2430

The ECM determines that the pressure sensor value change is less than a calibrated value.

P2431

The ECM determines that the difference between the Secondary Air Injection pressure sensor and the BARO sensor signal is greater than 10 kPa (1.5 psi) or less than -10 kPa (-1.5 psi) when the Secondary Air Injection Pump is commanded OFF. OR
The ECM determines that the difference between the Secondary Air Injection pressure sensor and the BARO sensor signal is greater than 50 kPa (21.8 psi) when the Secondary Air Injection Pump is commanded ON.

DTC P2432

The Secondary Air Pressure sensor signal is less than 0.3 V for greater than 6 s.

DTC P2433

The Secondary Air Pressure sensor signal is greater than 4.7 V for greater than 6 s.

DTCs P2430, P2431, P2432 and P2433 are Type B DTCs.

Schematic Reference

Engine Controls Schematics (LEA) , Engine Controls Schematics (LUK)

Connector End View Reference

Description and Operation

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Ignition ON, observe the DTC information with a scan tool. Verify that DTC P0641 or P0651 is not set. If a DTC is set, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) for further diagnosis.
Compare the scan tool BARO pressure parameter to the «Altitude Versus Barometric Pressure»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-specifications__altitude-versus-barometric-pressure) table. The BARO should be within the specified range displayed in the table for the specific altitude. If not within the specified range, refer to «DTC P2227-P2230»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-dtc-p0411-luk-to-dtc-p2635-and-symptom-troubleshooting-diagnosis) for further diagnosis.
Compare the scan tool Secondary Air Injection Pressure Sensor pressure parameter to the BARO reading. The readings should be within 3 kPa (0.4 psi).
Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Ignition OFF, disconnect the harness connector at the Q29 Secondary Air Injection Solenoid Valve.
Ignition OFF and all vehicle systems OFF. It may take up to 2 minutes for all vehicle systems to power down. Test for less than 5 ohms between the low reference circuit terminal 3 and ground. If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the K20 ECM.
Ignition ON, test for 4.8-5.2 V between the 5 V reference circuit terminal 1 and ground. If less than the specified range, test the 5 V reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K20 ECM. If greater than the specified range, test the 5 V reference circuit for a short to voltage. If the circuit tests normal, replace the K20 ECM.
Verify the scan tool Secondary Air Injection Pressure Sensor voltage parameter is less than 0.5 V. If greater than the specified range, test the signal circuit terminal 2 for a short to voltage. If the circuit tests normal, replace the K20 ECM.
Install a 3 A fused jumper wire between the signal circuit terminal 2 and the 5 V reference circuit terminal 1. Verify the scan tool Secondary Air Injection Pressure Sensor voltage parameter is greater than 4.8 V. If less than the specified range, test the signal circuit for short to ground or an open/high resistance. If the circuit tests normal, replace the K20 ECM.
If all circuits test normal, test or replace the Q29 Secondary Air Injection Solenoid Valve.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

«Secondary Air Injection Check Valve Replacement»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions)
«Control Module References»(/buick/regal/v-2009-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for Engine Control Module replacement, setup, and programming

Perform the «Diagnostic System Check - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
5 V Reference	P0651, P2432	P2431	P0651, P2431	P2430, P2431
Secondary Air Injection Pressure Sensor Signal	P2432	P2432	P2433	P2430, P2431
Low Reference		P2433		P2430, P2431

Circuit	Short to Ground	Open	Short to Voltage
Parameter Normal Range: BARO Operating Conditions: Engine running under various operating conditions
5 V Reference	41 kPa (5.9 psi)	41 kPa (5.9 psi)	111 kPa (16.1 psi)
AIR Pressure Sensor Signal	42 kPa (6.1 psi)	41 kPa (5.9 psi)	150 kPa (21.8 psi)
Low Reference		145 kPa (21 psi)

Secondary Air Injection Pressure Sensor

The secondary air injection system aids in the reduction of hydrocarbon emissions during a cold start. The electric air pump forces fresh air into the exhaust stream in order to accelerate the catalyst operation. A secondary air injection pressure sensor is used to monitor the air flow from the secondary air injection pump. The Engine Control Module (ECM) supplies voltage to the 5 V reference circuit and provides a ground for the low reference circuit. The sensor provides a signal voltage to the ECM relative to the pressure changes within the secondary air injection system.

DTC P2430

DTC P0412, P0418, P0606, P0641, P0651, P2432, or P2433 is not set.
Greater than 60 min has elapsed since the last cold start.
The barometric pressure (BARO) is greater than 60 kPa (8.7 psi).
The intake air temperature (IAT) is greater than -11°C (12°F).
The engine coolant temperature (ECT) is between -11 to +60°C (12-140°F).
The ignition voltage is between 10-32 V.
The manifold absolute pressure (MAP) sensor is greater than 20 kPa (2.9 psi).
The engine speed is less than 5, 000 RPM.
The mass air flow (MAF) is less than 50 g/s.
The AIR pump is commanded ON.
DTC P2430 runs continuously when the above conditions are met.

DTC P2431

DTC P0101, P0102, P0103, P0300, P0301, P0302, P0304, P0412, P0418, P0606, P0641, P0651, P2432, or P2433 is not set.
The barometric pressure (BARO) is greater than 60 kPa (8.7 psi).
The intake air temperature (IAT) is greater than -11°C (12°F).
The engine coolant temperature (ECT) is between -11 to +60°C (12-140°F).
The ignition voltage is between 10-32 V.
The manifold absolute pressure (MAP) sensor is greater than 20 kPa (2.9 psi).
Run/Crank is not active.
The engine speed is less than 5, 000 RPM.
The mass air flow (MAF) is less than 50 g/s.
Greater than 60 minutes has elapsed since the last cold start.
DTC P2431 runs continuously when the above conditions are met.

P2432 and P2433

DTC P0606, P0641, or P0651 is not set.
The ignition is ON or the engine is running.
DTC P2432 and P2433 run continuously when the above conditions are met.

P2430

The ECM determines that the pressure sensor value change is less than a calibrated value.

P2431

The ECM determines that the difference between the Secondary Air Injection pressure sensor and the BARO sensor signal is greater than 14 kPa (2.0 psi) or less than -10 kPa (-1.5 psi) when the Secondary Air Injection Pump is commanded OFF. OR
The ECM determines that the difference between the Secondary Air Injection pressure sensor and the BARO sensor signal is greater than 50 kPa (21.8 psi) when the Secondary Air Injection Pump is commanded ON.

DTC P2432

The Secondary Air Pressure sensor signal is less than 0.3 V for greater than 5 s.

DTC P2433

The Secondary Air Pressure sensor signal is greater than 4.7 V for greater than 5 s.

DTCs P2430, P2431, P2432 and P2433 are Type B DTCs.

Schematic Reference

Engine Controls Schematics (LEA) , Engine Controls Schematics (LUK)

Connector End View Reference

Description and Operation

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Ignition ON, observe the DTC information with a scan tool. Verify that DTC P0641 or P0651 is not set. If a DTC is set, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) for further diagnosis.
Compare the scan tool BARO pressure parameter to the «Altitude Versus Barometric Pressure»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-specifications__altitude-versus-barometric-pressure) table. The BARO should be within the specified range displayed in the table for the specific altitude. If not within the specified range, refer to «DTC P0106»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-dtc-p0010-to-dtc-p0411) for further diagnosis.
Compare the scan tool Secondary Air Injection Pressure Sensor pressure parameter to the BARO reading. The readings should be within 3 kPa (0.4 psi).
Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Ignition OFF, disconnect the harness connector at the Q29 Secondary Air Injection Solenoid Valve.
Ignition OFF and all vehicle systems OFF. It may take up to 2 minutes for all vehicle systems to power down. Test for less than 5 ohms between the low reference circuit terminal 3 and ground. If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the K20 ECM.
Ignition ON, test for 4.8-5.2 V between the 5 V reference circuit terminal 1 and ground. If less than the specified range, test the 5 V reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K20 ECM. If greater than the specified range, test the 5 V reference circuit for a short to voltage. If the circuit tests normal, replace the K20 ECM.
Verify the scan tool Secondary Air Injection Pressure Sensor voltage parameter is less than 0.5 V. If greater than the specified range, test the signal circuit terminal 2 for a short to voltage. If the circuit tests normal, replace the K20 ECM.
Install a 3 A fused jumper wire between the signal circuit terminal 2 and the 5 V reference circuit terminal 1. Verify the scan tool Secondary Air Injection Pressure Sensor voltage parameter is greater than 4.8 V. If less than the specified range, test the signal circuit for short to ground or an open/high resistance. If the circuit tests normal, replace the K20 ECM.
If all circuits test normal, test or replace the Q29 Secondary Air Injection Solenoid Valve.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

«Secondary Air Injection Check Valve Replacement»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions)
«Control Module References»(/buick/regal/v-2009-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for Engine Control Module replacement, setup, and programming

Perform the «Diagnostic System Check - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Circuit	Short to Ground	Open/High Resistance	Short to Voltage
Secondary Air Injection Solenoid Valve Relay Coil Voltage Supply	P0412	P0412	P0690
Secondary Air Injection Solenoid Valve Relay Coil Control	P0412	P0412	P0412, P0690
Secondary Air Injection Solenoid Valve Voltage Supply	P0411	P0411	P2440
Secondary Air Injection Solenoid Valve Ground		P0411

The secondary air injection system aids in the reduction of hydrocarbon emissions during a cold start. The electric air pump forces fresh air into the exhaust stream in order to accelerate the catalyst operation. A pressure sensor is used to monitor the air flow from the secondary air injection pump. The engine control module (ECM) supplies voltage to the 5-volt reference circuit and supplies a ground to the low reference circuit. The sensor provides a signal voltage to the ECM relative to the pressure changes within the secondary air injection system.

The diagnostic uses 3 phases to test the secondary air injection system as follows

DTCs P0411 and P2430 run during Phase 1
DTCs P2430 and P2440 run during Phase 2
DTC P2444 runs during Phase 3

DTCs P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0114, P0116, P0117, P0118, P0121, P0122, P0123, P0128, P0201, P0202, P0203, P0204, P0222, P0223, P0261, P0262, P0264, P0265, P0267, P0268, P0270, P0271, P0300, P0301, P0302, P0303, P0304, P0351, P0352, P0353, P0354, P0411, P0412, P0418, P0420, P0606, P0641, P0651, P1248, P1249, P124A, P124B, P2147, P2148, P2150, P2151, P2153, P2154, P2156, P2157, P2430, P2431, P2432 or P2433 are not set.
Greater than 30 min has elapsed since the last cold start.
The ignition voltage is between 10-32 V.
The barometric pressure (BARO) is greater than 60 kPa (8.7 psi).
The engine coolant temperature (ECT) is between -11 to +60°C (12-140°F).
The intake air temperature (IAT) is greaterr than -11°C (+12°F).
The manifold absolute pressure (MAP) sensor is greater than 20 kPa (2.9 psi).
The mass air flow (MAF) is less than 50 g/s.
The engine speed is less than 5, 000 RPM.
The secondary air injection system is commanded ON.
The DTC runs continuously once the above conditions are met for greater than 3 s.

The ECM detects that the secondary air system pressure is less than a calibrated threshold for greater than 1.5 s.

DTC P2440 is a Type B DTC.

Schematic Reference

Engine Controls Schematics (LEA) , Engine Controls Schematics (LUK)

Connector End View Reference

Description and Operation

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Ignition ON, compare the scan tool BARO pressure parameter to the «Altitude Versus Barometric Pressure»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-specifications__altitude-versus-barometric-pressure) table. The BARO pressure should be within the specified range displayed in the table for the specific altitude. If not within the specified range, refer to «DTC P0106»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-dtc-p0010-to-dtc-p0411) for further diagnosis.
Compare the scan tool Secondary Air Injection Pressure Sensor pressure parameter to the BARO reading. The readings should be within 3 kPa (0.4 psi). If not within the specified range, refer to «DTC P2430-P2433 (LEA)»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-dtc-p0411-luk-to-dtc-p2635-and-symptom-troubleshooting-diagnosis) , «DTC P2430-P2433 (LAF, LUK)»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-dtc-p0411-luk-to-dtc-p2635-and-symptom-troubleshooting-diagnosis) .
Command the Secondary Air Injection Solenoid Valve Open and Closed with a scan tool. Listen and feel for Solenoid Valve operation. The Solenoid Valve should respond to the scan tool commands. Repeat as necessary in order to verify Air Solenoid Valve operation.
Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Ignition OFF, disconnect the harness connector at the Q29 Secondary Air Injection Solenoid Valve.
Ignition OFF and all vehicle systems OFF. It may take up to 2 minutes for all vehicle systems to power down. Test for less than 5 ohms between the ground circuit terminal 4 and ground. If greater than the specified range, repair the ground circuit for an open/high resistance.
Connect a test lamp between the Q29 Secondary Air Injection Solenoid Valve ignition voltage circuit terminal 5 and ground.
Ignition ON, command the Secondary Air Injection Solenoid Valve Open and Closed with a scan tool. The test lamp should respond to the scan tool commands. If the test lamp is always OFF, test the ignition circuit for a short to ground, or an open/high resistance. If the circuit tests normal, replace the Secondary Air Injection Solenoid Valve relay. If the test lamp is always ON, test the ignition circuit for a short to voltage. If the circuit tests normal, replace the Secondary Air Injection Solenoid Valve relay.
Ignition OFF, remove the Q29 Secondary Air Injection Solenoid Valve.
Connect the Q29 Secondary Air Injection Solenoid Valve harness connector.
Ignition ON, command the Secondary Air Injection Solenoid Valve Open and Closed with a scan tool while observing the check valve assembly. The valve should open and close in response to the scan tool commands. If the valve does not operate as specified, replace the Q29 Secondary Air Injection Solenoid Valve.
Disconnect the Secondary Air Injection Pump hose/pipe from the Q29 Secondary Air Injection Solenoid Valve.
Ignition ON, command the Secondary Air Injection Pump ON with a scan tool. Verify airflow to the Secondary Air Injection Solenoid Valve. If there is limited or no airflow to the Secondary Air Injection Solenoid Valve, inspect for the following: All Secondary Air Injection system Hoses/pipes for a restriction or blockage Secondary Air Injection Pump Hose/pipe for leaks or loose connections If a condition is located, repair or replace the affected component as necessary.
If all circuits and hoses/pipes test normal, test or replace the Q29 Secondary Air Injection Solenoid Valve.

Ignition OFF, disconnect the harness connector at the Q29 Secondary Air Injection Solenoid Valve.
Test for 5-15 ohms between the Q29 Secondary Air Injection Solenoid Valve terminals 4 and 5. If not within the specified range, replace the Q29 Secondary Air Injection Solenoid Valve.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

«Relay Replacement (Within an Electrical Center)»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-repair-instructions) , «Relay Replacement (Attached to Wire Harness)»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-repair-instructions)
«Secondary Air Injection Check Valve Replacement»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions)
«Secondary Air Injection Check Valve Pipe Replacement»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions)
«Secondary Air Injection Pipe Replacement»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions)
«Secondary Air Injection Pump Replacement»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions)
«Secondary Air Injection Pump Inlet Hose Replacement»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions)
«Control Module References»(/buick/regal/v-2009-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for Engine Control Module replacement, setup, and programming

Perform the «Diagnostic System Check - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Circuit	Short to Ground	Open/High Resistance	Short to Voltage
Secondary Air Injection Solenoid Valve Relay Coil Voltage Supply	P0412	P0412	P0690
Secondary Air Injection Solenoid Valve Relay Coil Control	P0412	P0412	P0412, P0690
Secondary Air Injection Solenoid Valve Voltage Supply	P0411	P0411	P2440
Secondary Air Injection Solenoid Valve Ground		P0411

The secondary air injection system aids in the reduction of hydrocarbon emissions during a cold start. The electric air pump forces fresh air into the exhaust stream in order to accelerate the catalyst operation. A pressure sensor is used to monitor the air flow from the secondary air injection pump. The engine control module (ECM) supplies voltage to the 5-volt reference circuit and supplies a ground to the low reference circuit. The sensor provides a signal voltage to the ECM relative to the pressure changes within the secondary air injection system.

The diagnostic uses 3 phases to test the secondary air injection system as follows

DTCs P0411 and P2430 run during Phase 1
DTCs P2430 and P2440 run during Phase 2
DTC P2444 runs during Phase 3

DTCs P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0114, P0116, P0117, P0118, P0121, P0122, P0123, P0128, P0201, P0202, P0203, P0204, P0222, P0223, P0261, P0262, P0264, P0265, P0267, P0268, P0270, P0271, P0300, P0301, P0302, P0303, P0304, P0351, P0352, P0353, P0354, P0411, P0412, P0418, P0420, P0606, P0641, P0651, P1248, P1249, P124A, P124B, P2147, P2148, P2150, P2151, P2153, P2154, P2156, P2157, P2430, P2431, P2432 or P2433 are not set.
Greater than 30 min has elapsed since the last cold start.
The ignition voltage is between 10-32 V.
The barometric pressure (BARO) is greater than 60 kPa (8.7 psi).
The engine coolant temperature (ECT) is between -11 to +60°C (12-140°F).
The intake air temperature (IAT) is greater than -11°C (+12°F).
The manifold absolute pressure (MAP) sensor is greater than 20 kPa (2.9 psi).
The mass air flow (MAF) is less than 50 g/s.
The engine speed is less than 5, 000 RPM.
The secondary air injection system is commanded ON.
The DTC runs continuously once the above conditions are met for greater than 3 s.

The ECM detects that the secondary air system pressure is less than a calibrated threshold for greater than 1.5 s.

DTC P2440 is a Type B DTC.

Schematic Reference

Engine Controls Schematics (LEA) , Engine Controls Schematics (LUK)

Connector End View Reference

Description and Operation

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Ignition ON, compare the scan tool BARO pressure parameter to the «Altitude Versus Barometric Pressure»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-specifications__altitude-versus-barometric-pressure) table. The BARO pressure should be within the specified range displayed in the table for the specific altitude. If not within the specified range, refer to «DTC P2227-P2230»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-dtc-p0411-luk-to-dtc-p2635-and-symptom-troubleshooting-diagnosis) for further diagnosis.
Compare the scan tool Secondary Air Injection Pressure Sensor pressure parameter to the BARO reading. The readings should be within 3 kPa (0.4 psi). If not within the specified range, refer to «DTC P2430-P2433 (LEA)»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-dtc-p0411-luk-to-dtc-p2635-and-symptom-troubleshooting-diagnosis) , «DTC P2430-P2433 (LAF, LUK)»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-dtc-p0411-luk-to-dtc-p2635-and-symptom-troubleshooting-diagnosis) .
Command the Secondary Air Injection Solenoid Valve Open and Closed with a scan tool. Listen and feel for Solenoid Valve operation. The Solenoid Valve should respond to the scan tool commands. Repeat as necessary in order to verify Air Solenoid Valve operation.
Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Ignition OFF, disconnect the harness connector at the Q29 Secondary Air Injection Solenoid Valve.
Ignition OFF and all vehicle systems OFF. It may take up to 2 minutes for all vehicle systems to power down. Test for less than 5 ohms between the ground circuit terminal 4 and ground. If greater than the specified range, repair the ground circuit for an open/high resistance.
Connect a test lamp between the Q29 Secondary Air Injection Solenoid Valve ignition voltage circuit terminal 5 and ground.
Ignition ON, command the Secondary Air Injection Solenoid Valve Open and Closed with a scan tool. The test lamp should respond to the scan tool commands. If the test lamp is always OFF, test the ignition circuit for a short to ground, or an open/high resistance. If the circuit tests normal, replace the Secondary Air Injection Solenoid Valve relay. If the test lamp is always ON, test the ignition circuit for a short to voltage. If the circuit tests normal, replace the Secondary Air Injection Solenoid Valve relay.
Ignition OFF, remove the Q29 Secondary Air Injection Solenoid Valve.
Connect the Q29 Secondary Air Injection Solenoid Valve harness connector.
Ignition ON, command the Secondary Air Injection Solenoid Valve Open and Closed with a scan tool while observing the check valve assembly. The valve should open and close in response to the scan tool commands. If the valve does not operate as specified, replace the Q29 Secondary Air Injection Solenoid Valve.
Disconnect the Secondary Air Injection Pump hose/pipe from the Q29 Secondary Air Injection Solenoid Valve.
Ignition ON, command the Secondary Air Injection Pump ON with a scan tool. Verify airflow to the Secondary Air Injection Solenoid Valve. If there is limited or no airflow to the Secondary Air Injection Solenoid Valve, inspect for the following: All Secondary Air Injection system Hoses/pipes for a restriction or blockage Secondary Air Injection Pump Hose/pipe for leaks or loose connections If a condition is located, repair or replace the affected component as necessary.
If all circuits and hoses/pipes test normal, test or replace the Q29 Secondary Air Injection Solenoid Valve.

Ignition OFF, disconnect the harness connector at the Q29 Secondary Air Injection Solenoid Valve.
Test for 5-15 ohms between the Q29 Secondary Air Injection Solenoid Valve terminals 4 and 5. If not within the specified range, replace the Q29 Secondary Air Injection Solenoid Valve.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

«Relay Replacement (Within an Electrical Center)»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-repair-instructions) , «Relay Replacement (Attached to Wire Harness)»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-repair-instructions)
«Secondary Air Injection Check Valve Replacement»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions)
«Secondary Air Injection Pipe Replacement»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions)
«Secondary Air Injection Pump Replacement»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions)
«Secondary Air Injection Pump Inlet Hose Replacement»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions)
«Control Module References»(/buick/regal/v-2009-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for Engine Control Module replacement, setup, and programming

Perform the «Diagnostic System Check - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Circuit	Short to Ground	Open/High Resistance	Short to Voltage
Secondary Air Injection Pump Relay Coil Voltage Supply	P0418	P0418	P0690
.Secondary Air Injection Pump Relay Coil Control	P0416	P0418	P0690, P2431
Secondary AIR Injection Pump Voltage Supply		P0411, P2440	P2444
Secondary AIR Injection Pump Ground		P0411, P2440

The secondary air injection system aids in the reduction of hydrocarbon emissions during a cold start. The electric air pump forces fresh air into the exhaust stream in order to accelerate the catalyst operation. A pressure sensor is used to monitor the air flow from the secondary air injection pump. The engine control module (ECM) supplies voltage to the 5-volt reference circuit and supplies a ground to the low reference circuit. The sensor provides a signal voltage to the ECM relative to the pressure changes within the secondary air injection system.

The diagnostic uses 3 phases to test the secondary air injection system as follows

DTCs P0411 and P2430 run during Phase 1
DTCs P2430 and P2440 run during Phase 2
DTC P2444 runs during Phase 3

During phase 3, neither the secondary air injection pump nor the secondary air injection solenoid valve is activated. Secondary air injection pump deactivation is tested. Expected system pressure equals BARO.

DTCs P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0114, P0116, P0117, P0118, P0121, P0122, P0123, P0128, P0201, P0202, P0203, P0204, P0222, P0223, P0261, P0262, P0264, P0265, P0267, P0268, P0270, P0271, P0300, P0301, P0302, P0303, P0304, P0351, P0352, P0353, P0354, P0411, P0412, P0418, P0420, P0606, P0641, P0651, P1248, P1249, P124A, P124B, P2147, P2148, P2150, P2151, P2153, P2154, P2156, P2157, P2430, P2431, P2432 or P2433 are not set.
Greater than 60 min has elapsed since the last cold start.
The ignition voltage is between 10-32 V.
The barometric pressure (BARO) is greater than 60 kPa (8.7 psi).
The engine coolant temperature (ECT) is between -11 to +60°C (12-140°F).
The intake air temperature (IAT) is warmer than -11°C (+12°F).
The manifold absolute pressure (MAP) sensor is greater than 20 kPa (2.9 psi).
The engine speed is less than 5, 000 RPM.
The mass air flow (MAF) is less than 50 g/s.
The AIR system is commanded ON.
The DTC runs continuously once the above conditions are met for greater than 4 s.

The ECM detects that the Secondary Air System pressure is greater than expected for greater than 2 s.

DTC P2444 is a Type B DTC.

Schematic Reference

Engine Controls Schematics (LEA) , Engine Controls Schematics (LUK)

Connector End View Reference

Description and Operation

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Ignition ON, compare the scan tool BARO pressure parameter to the «Altitude Versus Barometric Pressure»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-specifications__altitude-versus-barometric-pressure) table. The BARO pressure should be within the specified range displayed in the table for the specific altitude. If not within the specified range, refer to «DTC P0106»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-dtc-p0010-to-dtc-p0411) for further diagnosis
Ignition ON, compare the scan tool Secondary Air Pressure Sensor pressure parameter to the BARO reading. The readings should be within 3 kPa (0.4 psi). If greater than the specified range, refer to «DTC P2430-P2433 (LEA)»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-dtc-p0411-luk-to-dtc-p2635-and-symptom-troubleshooting-diagnosis) , «DTC P2430-P2433 (LAF, LUK)»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-dtc-p0411-luk-to-dtc-p2635-and-symptom-troubleshooting-diagnosis) .
Command the Secondary Air Injection Pump Relay ON and OFF with a scan tool. You should hear an audible click as the relay is commanded ON and OFF. If the relay does not respond to the scan tool commands, refer to «DTC P0412 or P0418»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-dtc-p0411-luk-to-dtc-p2635-and-symptom-troubleshooting-diagnosis) for further diagnosis.
Ignition ON, command the Secondary Air Injection Pump Relay ON and OFF with a scan tool. The Secondary Air Pump should respond to the scan tool commands.
Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Ignition OFF, disconnect the harness connector at the G21 Secondary Air Injection Pump.
Ignition ON, verify that a test lamp does not illuminate between the G21 Secondary Air Injection Pump ignition voltage circuit terminal A and ground. If the test lamp illuminates, test the ignition circuit for a short to voltage.
If the circuit tests normal replace the Secondary Air Injection Pump Relay.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Relay Replacement (Within an Electrical Center) , Relay Replacement (Attached to Wire Harness)

Perform the «Diagnostic System Check - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Circuit	Short to Ground	Open/High Resistance	Short to Voltage
Secondary Air Injection Pump Relay Coil Voltage Supply	P0418	P0418	P0690
Secondary Air Injection Pump Relay Coil Control	P0416	P0418	P0690, P2431
Secondary AIR Injection Pump Voltage Supply		P0411, P2440	P2444
Secondary AIR Injection Pump Ground		P0411, P2440

The secondary air injection system aids in the reduction of hydrocarbon emissions during a cold start. The electric air pump forces fresh air into the exhaust stream in order to accelerate the catalyst operation. A pressure sensor is used to monitor the air flow from the secondary air injection pump. The engine control module (ECM) supplies voltage to the 5-volt reference circuit and supplies a ground to the low reference circuit. The sensor provides a signal voltage to the ECM relative to the pressure changes within the secondary air injection system.

The diagnostic uses 3 phases to test the secondary air injection system as follows

DTCs P0411 and P2430 run during Phase 1
DTCs P2430 and P2440 run during Phase 2
DTC P2444 runs during Phase 3

DTC P0101, P0102, P0103, P0111, P0112, P0113, P0114, P0116, P0117, P0118, P0128, P0201, P0202, P0203, P0204, P0261, P0262, P0264, P0265, P0267, P0268, P0270, P0271, P0273, P0274, P0276, P0277, P0280, P0282, P0283, P0300, P0301, P0302, P0303, P0304, P0351, P0352, P0353, P0354, P0412, P0418, P0420, P0606, P0641, P0651, P1248, P1249, P124A, P124B, P2147, P2148, P2150, P2151, P2153, P2154, P2156, P2157, P2227, P2228, P2229, P2230, P2430, P2431, P2432, or P2433 is not set.
Greater than 30 min has elapsed since the last cold start.
The ignition voltage is between 10-32 V.
The barometric pressure (BARO) is greater than 60 kPa (8.7 psi).
The engine coolant temperature (ECT) is between -11 to +56°C (12-133°F).
The intake air temperature (IAT) is greater than -11°C (+12°F).
The manifold absolute pressure (MAP) sensor is greater than 20 kPa (2.9 psi).
The engine speed is less than 5, 000 RPM.
The mass air flow (MAF) is less than 50 g/s.
The AIR system is commanded ON.
The DTC runs continuously once the above conditions are met for greater than 4 s.

The ECM detects that the Secondary Air System pressure is greater than expected for greater than 4 s.

DTC P2444 is a Type B DTC.

Schematic Reference

Engine Controls Schematics (LEA) , Engine Controls Schematics (LUK)

Connector End View Reference

Description and Operation

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Ignition ON, compare the scan tool BARO pressure parameter to the «Altitude Versus Barometric Pressure»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-specifications__altitude-versus-barometric-pressure) table. The BARO pressure should be within the specified range displayed in the table for the specific altitude. If not within the specified range, refer to «DTC P2227-P2230»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-dtc-p0411-luk-to-dtc-p2635-and-symptom-troubleshooting-diagnosis) for further diagnosis
Ignition ON, compare the scan tool Secondary Air Pressure Sensor pressure parameter to the BARO reading. The readings should be within 3 kPa (0.4 psi). If greater than the specified range, refer to «DTC P2430-P2433 (LEA)»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-dtc-p0411-luk-to-dtc-p2635-and-symptom-troubleshooting-diagnosis) , «DTC P2430-P2433 (LAF, LUK)»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-dtc-p0411-luk-to-dtc-p2635-and-symptom-troubleshooting-diagnosis) .
Command the Secondary Air Injection Pump Relay ON and OFF with a scan tool. You should hear and feel a click as the relay is commanded ON and OFF. If the relay does not respond to the scan tool commands, refer to «DTC P0412 or P0418»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-dtc-p0411-luk-to-dtc-p2635-and-symptom-troubleshooting-diagnosis) for further diagnosis.
Ignition ON, command the Secondary Air Injection Pump Relay ON and OFF with a scan tool. The Secondary Air Pump should turn ON and OFF in response to the scan tool commands.
Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Ignition OFF, disconnect the harness connector at the G21 Secondary Air Injection Pump.
Ignition ON, verify that a test lamp does not illuminate between the G21 Secondary Air Injection Pump ignition voltage circuit terminal A and ground. If the test lamp illuminates, test the ignition circuit for a short to voltage.
If the circuit tests normal replace the KR25 Secondary Air Injection Pump Relay.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Relay Replacement (Within an Electrical Center) , Relay Replacement (Attached to Wire Harness)

Perform the «Diagnostic System Check - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Circuit	Short to Ground	Open or High Resistance	Short to Voltage	Signal Performance
IGN Voltage	P2534	P2534

The fuel pump control module monitors the ignition voltage circuit in order to determine if the voltage is within the normal operating range.

The engine is running.

The FPCM detects that the IGN voltage is less than 6.0 V.

DTC P2534 is a Type A DTC.

Schematic Reference

Engine Controls Schematics (LEA) , Engine Controls Schematics (LUK)

Connector End View Reference

Description and Operation

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Verify that DTC P0562 is not set. If DTC P0562 is set, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) .
Ignition OFF, disconnect the harness connector of the K27 fuel pump control module.
Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal 15 and ground. If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance.
If all circuits test normal, replace the K27 fuel pump control module.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

«Relay Replacement (Within an Electrical Center)»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-repair-instructions) , «Relay Replacement (Attached to Wire Harness)»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-repair-instructions)
«Control Module References»(/buick/regal/v-2009-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for fuel pump control module replacement, setup, and programming

Perform the «Diagnostic System Check - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for a overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

To improve shift feel, the transmission control module (TCM) is constantly sending the engine control module (ECM) serial data messages with information regarding it's request for modifying engine speed or torque. The serial data messages are sent through two circuits which are part of a communication network called the controller area network (CAN). The ECM sets DTC P2544 when it detects a discrepancy in the structure of the message causing the integrity of the message to be questioned.

An intermittent fault in the CAN circuits will cause the ECM to set DTC P2544.

The engine run time is greater than 0.5 s.
No other CAN errors are present.

The ECM detects that the engine speed and torque modification messages from the TCM are either corrupted or intermittently missing for greater than 4 s.

DTC P2544 is a Type B DTC.
The TCM commands maximum line pressure during shifts, which results in harsh shifts.
The TCM freezes adaptive functions.

DTC P2544 is a Type B DTC.

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

DTC P2544 is an informational DTC. Diagnose all other engine control DTCs prior to DTC P2544. Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) .
If there are no other engine controls DTCs, diagnosis is accomplished by looking for an intermittent CAN circuit fault. Refer to «Scan Tool Does Not Communicate with High Speed GMLAN Device»(/buick/regal/v-2009-2013/remont/communication-devices/#data-communications-system) .

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for TCM replacement, setup, and programming.

Perform the «Diagnostic System Check - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
Fuel Pump High Control	P0231	P023F	P0232	P023F, P2635
Fuel Pump Low Control		P023F		P023F, P2635

The engine control module (ECM) supplies voltage to the fuel pump control module when the ECM detects that the ignition is on. The voltage from the ECM to the fuel pump control module remains active for 2 seconds, unless the engine is in crank or run. While this voltage is being received, the fuel pump control module closes the ground switch of the fuel pump and also supplies a varying voltage to the fuel tank pump module in order to maintain the desired fuel rail pressure.

DTC P018B, P018C, P018D, P0231, P0232, P023F, P064A, P1255 or P06A6 are not active.
DTC P0641 has not failed this ignition cycle.
Fuel pump control is enabled and the fuel pump control state is normal.
The system voltage is greater than 11 V.
The engine has been running for more than 30 seconds.

This DTC sets when the fuel pump control module detects a predetermined fuel pressure performance degradation between the desired fuel rail pressure and the current fuel rail pressure.

DTC P2635 is a Type B DTC.

On vehicles equipped with a high pressure mechanical pump on Direct Fuel Injection engines, the vehicle may continue to run even though the pump in the fuel tank is not operating.

Schematic Reference

Engine Controls Schematics (LEA) , Engine Controls Schematics (LUK)

Connector End View Reference

Description and Operation

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Note. Do not replace the fuel pump control module based on a history DTC P2635. The DTC P2635 may be stored but that does not indicate a failure of the fuel pump control module. Refer to Strategy Based Diagnosis for further history DTC diagnostics.

Verify that DTCs P018C, P018D, P0231, P0232, or P023F are not set. If any of the DTC are set, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) .
Ignition OFF, disconnect the harness connector at the G12 fuel pump.
Ignition OFF, test for less than 5.0 ohms between the G12 fuel pump low reference circuit terminal 2 and ground. If greater than the specified range, test the G12 fuel pump low reference circuit for a high resistance. If the circuit tests normal, replace the K27 fuel pump control module.
Ignition OFF, install a test lamp between the control circuit terminal 1 and the low reference circuit terminal 2.
Ignition ON, command the ECM Fuel Pump Relay ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states. If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the K27 fuel pump control module. If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K27 fuel pump control module.
Perform the «Fuel System Diagnosis»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-dtc-p0411-luk-to-dtc-p2635-and-symptom-troubleshooting-diagnosis) to verify proper fuel pressure. If the fuel pressure is not normal, replace the G12 fuel pump
If all circuits test normal, replace the K27 fuel pump control module.

Perform the Diagnostic Repair Verification after completing the repair.

«Fuel Tank Fuel Pump Module Replacement (NT7)»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions) , «Fuel Tank Fuel Pump Module Replacement (NU6)»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions)
«Control Module References»(/buick/regal/v-2009-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for fuel pump control module replacement, programming and setup

Perform the «Diagnostic System Check - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Symptoms Description

Symptoms covers conditions that are not covered by DTCs. Certain conditions can cause multiple symptoms. These conditions are listed together under Symptoms Testing. Conditions that may only cause specific symptoms are listed separately under Additional Symptoms Testing. Perform the Symptoms Testing before using the Additional Symptoms Testing.

Symptoms Verification

Before using the Symptom tables, perform the following inspections

Verify that the malfunction indicator lamp (MIL) is operating correctly. Use the scan tool to command the lamp ON and OFF.
Verify that there are no DTCs that are stored.
Verify that the scan tool data is within a normal operating range. Refer to «Control Module References»(/buick/regal/v-2009-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for scan tool information.
Verify the customer concern.
Perform the Visual/Physical Inspection in this section. The visual/physical inspection is extremely important, and can lead to correcting a condition without additional testing. It may also help reveal the cause of an intermittent condition.

Identifying Intermittent Conditions

Many intermittent conditions occur with harness or connector movement due to engine torque, rough pavement, vibration or physical movements of a component. Refer to the following for a list of issues that may cause an intermittent condition

Moisture and water intrusion in connectors, terminals, and components
Incomplete connector mating
Poor terminal contact
High circuit or component resistance-High resistance can include any resistance, regardless of the amount, which can interrupt the operation of the component.
Harness that is too short or tight
Wire insulation that is chaffed or cut
High or low ambient temperature
High or low engine coolant temperatures
High underhood temperatures
Heat build up in component or circuit due to circuit resistance, poor terminal contact, or high electrical load
High or low system voltage
High vehicle load conditions
Rough road surfaces
Electro-magnetic interference (EMI)/circuit interference from relays, solenoids or other electrical surge
Incorrect installation of aftermarket, add on accessories

Visual/Physical Check

Verify that the control module grounds are clean, tight, and correctly located.
Verify that the vacuum hoses are not split or kinked, and are properly connected, as shown on the Vehicle Emission Control Information label.
Verify that the air filter is clean and free from restrictions.
Verify that there is no water intrusion in connectors terminals and components.
Inspect the air intake ducts for the following conditions: Collapsed Damaged areas Looseness Incorrect installation Leaking
Inspect for air leaks at the throttle body mounting area, the mass air flow (MAF) sensor and intake manifold sealing surfaces.
Inspect the wiring harness for the following conditions: Poor connections Pinches Cuts
Inspect for loose, damaged, unseated, or missing sensors/components.
Inspect the terminals for corrosion and correct contact.

Symptoms Testing

Backfire, Cuts Out/Misses, Detonation/Spark Knock, Dieseling/Run-On, Engine Control Module (ECM) Commanded Reduced Engine Power, Hard Start, Hesitation/Sag/Stumble, Lack of Power/Sluggishness/Sponginess, Poor Fuel Economy, Rough, Unstable, or Incorrect Idle and Stalling, or Surges/Chuggles

Test the fuel system for the following: Correct operation and pressure-Refer to «Fuel System Diagnosis»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-dtc-p0411-luk-to-dtc-p2635-and-symptom-troubleshooting-diagnosis) . Improperly operating fuel injectors-Refer to «Fuel Injector Solenoid Coil Test»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-dtc-p0411-luk-to-dtc-p2635-and-symptom-troubleshooting-diagnosis) . Improper fuel quality condition-Refer to «Alcohol/Contaminants-in-Fuel Diagnosis»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-dtc-p0411-luk-to-dtc-p2635-and-symptom-troubleshooting-diagnosis) .
Test the ignition system for the following: Spark plugs with incorrect heat range or an abnormal condition-Refer to «Spark Plug Inspection»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions__spark-plug-inspection) , and «Ignition System Specifications»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-specifications__ignition-system-specifications) . Coolant or oil fouled spark plugs-For diagnosis, refer to «Coolant in Combustion Chamber»(/buick/regal/v-2009-2013/remont/mechanical/#engine-mechanical-24l__coolant-in-combustion-chamber) , or «Oil Consumption Diagnosis»(/buick/regal/v-2009-2013/remont/mechanical/#engine-mechanical-24l__oil-consumption-diagnosis) . Secondary ignition system susceptible to moisture. Engine running, wet down the secondary ignition system with water from a spray bottle to help locate damaged or deteriorated components. Look/listen for arcing or misfiring as the water is applied. Weak spark using the «J 26792»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-special-tools-and-equipment__special-tools-diagnostic-tools) Spark Tester-Refer to «Electronic Ignition System Diagnosis»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-dtc-p0411-luk-to-dtc-p2635-and-symptom-troubleshooting-diagnosis) .
Inspect for the following conditions: Improper operation of the transmission torque converter clutch (TCC) - The scan tool should indicate an engine speed drop when the TCC is commanded ON. For Non-Hybrid equipped vehicles, refer to «Torque Converter Diagnosis»(/buick/regal/v-2009-2013/remont/automatic-trans/#automatic-transmission-6t406t456t50-diagnostic-information-and-procedures) . Improper operation of the A/C compressor An engine that runs lean or rich-Observe the Fuel Trim parameters with a scan tool. Refer to «DTC P0171 or P0172»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-dtc-p0010-to-dtc-p0411) . Slow responding heated oxygen sensors (HO2S). The heated oxygen sensors should respond quickly to different throttle positions. Refer to «DTC P0133, P0134, P013A, P013B, P013E, P013F, P0140, P1133, P2270, P2271, or P2A00»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-dtc-p0010-to-dtc-p0411) for additional information. CAUTION: Refer to «Heated Oxygen and Oxygen Sensor Caution»(/buick/regal/v-2009-2013/remont/oem-general-information/#dangers-warnings-and-cautions__heated-oxygen-and-oxygen-sensor-caution) . Water intrusion in the heated oxygen sensors connector NOTE: The embossed arrows on the mass air flow (MAF) sensor indicate the direction of the intake air flow. The arrows must point toward the engine. Improper MAF sensor installation. A mass air flow sensor that is improperly installed may cause a hard start. Install the mass air flow in the proper direction. Refer to «Mass Airflow Sensor with Intake Air Temperature Sensor Replacement»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions) . Improper mass air flow (MAF) sensor connections. Engine oil contaminated by fuel Split or kinked vacuum hoses-Verify that the routing and connections are as shown on the Vehicle Emission Control Information label. Excessive knock sensor system spark retard activity-Observe the Knock Retard parameter on the scan tool for activity more than 0°.
Electromagnetic interference (EMI) on the reference circuit, which can cause a misfire condition. You can usually detect electromagnetic interference with a scan tool by monitoring the engine speed parameter. A sudden increase in the engine speed parameter with little change in actual engine speed indicates that electromagnetic interference is present. Inspect the high voltage components near the ignition control circuit if a condition exists.
A crankshaft position sensor with an intermittent condition-Observe the scan tool Crankshaft Position Resync Counter parameter. The Resync Counter parameter should remain at 0 during all operating conditions, and when moving the related harnesses and connectors between the crankshaft position sensor and the ECM.
A stuck open evaporative emission (EVAP) canister purge solenoid.
Improper operation of the crankcase ventilation valve-Refer to «Crankcase Ventilation System Inspection/Diagnosis (Without Turbocharger)»(/buick/regal/v-2009-2013/remont/mechanical/#engine-mechanical-24l__crankcase-ventilation-system-inspectiondiagnosis-without-tur) .
The exhaust system components for the following: Physical damage or possible internal failure Restricted three-way catalytic converters For more information, refer to «Symptoms - Engine Exhaust»(/buick/regal/v-2009-2013/remont/exhaust/#engine-exhaust-system__symptoms-engine-exhaust) .
The engine cooling system for the following conditions: A thermostat with incorrect heat range. Refer to «Thermostat Diagnosis»(/buick/regal/v-2009-2013/remont/cooling-system-mechanical/#engine-cooling-system__thermostat-diagnosis) . Improper engine coolant level-If the level is low, refer to «Loss of Coolant»(/buick/regal/v-2009-2013/remont/cooling-system-mechanical/#engine-cooling-system__loss-of-coolant) .
Inspect the engine for the following mechanical failures: Refer to «Symptoms - Engine Mechanical»(/buick/regal/v-2009-2013/remont/mechanical/#engine-mechanical-24l) . Excessive oil in the combustion chamber or leaking valve seals Oil Consumption Incorrect cylinder compression Sticking or leaking valves Worn camshaft lobes Incorrect valve timing Worn rocker arms Broken valve springs Excessive carbon buildup in the combustion chambers-Clean the chambers with top engine cleaner. Follow the instructions on the can. Incorrect engine parts
If the above conditions do not address the symptom, refer to the additional symptoms tests.

Additional Symptoms Tests

Detonation/Spark Knock

Verify that the engine coolant temperature (ECT) has not shifted in value. Allow the engine to run and reach operating temperature. Observe the ECT Sensor parameter with a scan tool and compare the reading to that parameter listed on the «Engine Control Module Scan Tool Information (LUK)»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-scan-tool-information-all-systems__engine-control-module-scan-tool-information) , «Engine Control Module Scan Tool Information (LEA)»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-scan-tool-information-all-systems__engine-control-module-scan-tool-information) , list. If the reading is not in the range specified in the list, test the resistance of the engine coolant temperature sensor. Refer to «Temperature Versus Resistance»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-specifications__temperature-versus-resistance) , for resistance specifications. Replace the engine coolant temperature sensor if the resistance is not within specification. Refer to «Engine Coolant Temperature Sensor Replacement»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions) . If the sensor is within the specification, test the engine coolant temperature sensor circuits for high resistance.
Test for an engine overheating condition. Refer to «Engine Overheating»(/buick/regal/v-2009-2013/remont/cooling-system-mechanical/#engine-cooling-system__engine-overheating) .
Inspect for excessive carbon buildup in the combustion chambers. Clean the chambers with Top Engine Cleaner, if necessary. Follow the instructions on the can.
If there are no engine mechanical faults, fill the fuel tank with a known high quality fuel that meets the vehicle minimum octane requirements.

Engine Control Module (ECM) Commanded Reduced Engine Power (LUK)

Under certain conditions the engine control module may limit engine power by reducing engine torque and, for some vehicles, fuel pressure as well. For most, but not all of the conditions, the engine control module will illuminate the reduced engine power lamp on the instrument panel cluster, however a DTC may not be set. Observe the scan tool Reduced Engine Power History parameter, if applicable, or refer to Engine Control Module Scan Tool Information (LUK) , Engine Control Module Scan Tool Information (LEA) to determine the reason for the reduced engine power event.

Verify or inspect for the following

Vehicle being operated at sustained high engine speeds, or, towing heavy loads up an incline for an extended period of time, which may cause the engine oil or coolant to overheat. A repair may not be necessary. Inspect the airflow passageways in front of the engine for obstructions and clear away any debris or foreign material that is found. If no obstructions are found, review approved driving habits with the customer. The customer may need to operate the vehicle at a higher engine speed to improve cooling system performance, or, at a slower engine speed to reduce engine load.
A cooling fan condition which may cause the engine control module to reduce engine power. Refer to «Cooling Fan Description and Operation (LAF, LEA, LUK)»(/buick/regal/v-2009-2013/remont/cooling-system-mechanical/#engine-cooling-system__cooling-fan-description-and-operation-24l) , «Cooling Fan Description and Operation (LDK or LHU)»(/buick/regal/v-2009-2013/remont/cooling-system-mechanical/#engine-cooling-system__cooling-fan-description-and-operation-20l) , and «Cooling System Description and Operation»(/buick/regal/v-2009-2013/remont/cooling-system-mechanical/#engine-cooling-system__cooling-system-description-and-operation) to verify correct operation of the cooling fan.
Temporarily reduced engine power. Under extremely cold ambient temperatures some SIDI equipped vehicles may experience engine control module commanded reduced engine power for a few minutes during engine warm-up. This would be a normal condition, noticeable only at wide open throttle, and the reduced engine power lamp would not be illuminated.
If the vehicle is equipped with the OnStar® feature, reduced engine power may be due to OnStar® remote command. Verify the vehicle is not in the OnStar® initiated Stolen Vehicle Slowdown mode. Refer to «OnStar Stolen Vehicle Slowdown Active»(/buick/regal/v-2009-2013/remont/door-locks-anti-theft-systems/#immobilizer-system) , and «Remote Vehicle Speed Limiting Description and Operation»(/buick/regal/v-2009-2013/remont/door-locks-anti-theft-systems/#immobilizer-system__remote-vehicle-speed-limiting-description-and) for additional information.
Excessively high fuel pressure condition. Refer to «Fuel System Diagnosis»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-dtc-p0411-luk-to-dtc-p2635-and-symptom-troubleshooting-diagnosis) , and «Fuel System Description»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-description-and-operation) to verify fuel system operation.
Maximum recommended engine oil life exceeded. Refer to the Owners Manual for scheduled maintenance recommendations.
Intake air temperature out of range too high. Engine running, observe the scan tool IAT Sensor parameter. The readings should be between -40°C and +149°C (-40°F and +300°F). Refer to «DTC P0112, P0113, or P0114 (With LUK)»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-dtc-p0010-to-dtc-p0411) , «DTC P0112, P0113, or P0114 (With LEA)»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-dtc-p0010-to-dtc-p0411) for additional information.
Fuel temperature out of range too high.

Engine Control Module (ECM) Commanded Reduced Engine Power (LAF or LEA)

Verify or inspect for the following

Vehicle being operated at sustained high engine speeds, or, towing heavy loads up an incline for an extended period of time, which may cause the engine oil or coolant to overheat. A repair may not be necessary. Inspect the airflow passageways in front of the engine for obstructions and clear away any debris or foreign material that is found. If no obstructions are found, review approved driving habits with the customer. The customer may need to operate the vehicle at a higher engine speed to improve cooling system performance, or, at a slower engine speed to reduce engine load.
A cooling fan condition which may cause the engine control module to reduce engine power. Refer to «Cooling Fan Description and Operation (LAF, LEA, LUK)»(/buick/regal/v-2009-2013/remont/cooling-system-mechanical/#engine-cooling-system__cooling-fan-description-and-operation-24l) , «Cooling Fan Description and Operation (LDK or LHU)»(/buick/regal/v-2009-2013/remont/cooling-system-mechanical/#engine-cooling-system__cooling-fan-description-and-operation-20l) , and «Cooling System Description and Operation»(/buick/regal/v-2009-2013/remont/cooling-system-mechanical/#engine-cooling-system__cooling-system-description-and-operation) to verify correct operation of the cooling fan.
Temporarily reduced engine power. Under extremely cold ambient temperatures some SIDI equipped vehicles may experience engine control module commanded reduced engine power for a few minutes during engine warm-up. This would be a normal condition, noticeable only at wide open throttle, and the reduced engine power lamp would not be illuminated.
If the vehicle is equipped with the OnStar® feature, reduced engine power may be due to OnStar® remote command. Verify the vehicle is not in the OnStar® initiated Stolen Vehicle Slowdown mode. Refer to «OnStar Stolen Vehicle Slowdown Active»(/buick/regal/v-2009-2013/remont/door-locks-anti-theft-systems/#immobilizer-system) , and «Remote Vehicle Speed Limiting Description and Operation»(/buick/regal/v-2009-2013/remont/door-locks-anti-theft-systems/#immobilizer-system__remote-vehicle-speed-limiting-description-and) for additional information.
Excessively high fuel pressure condition. Refer to «Fuel System Diagnosis»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-dtc-p0411-luk-to-dtc-p2635-and-symptom-troubleshooting-diagnosis) , and «Fuel System Description»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-description-and-operation) to verify fuel system operation.
Maximum recommended engine oil life exceeded. Refer to the Owners Manual for scheduled maintenance recommendations.
Intake air temperature out of range too high. Observe the scan tool IAT Sensor 1 and IAT Sensor 2 parameters. The readings should be within 30°C (54°F) of a each other. Refer to «DTC P2199»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-dtc-p0411-luk-to-dtc-p2635-and-symptom-troubleshooting-diagnosis) for additional information.
Fuel temperature out of range too high.

Fuel Odor

Inspect for leaking, damaged, or deteriorated fuel lines.
Inspect for a saturated EVAP canister-Refer to «Evaporative Emission Control System Description»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-description-and-operation) .
Inspect for a condition with the internal components of the fuel tank assembly-Refer to «Fuel System Description»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-description-and-operation) .

Hard Start

Observe the scan tool Throttle Body Idle Airflow Compensation parameter. A value greater than 80% may indicate an excessive accumulation of deposits in the throttle bore. Inspect the throttle body and bore and clean, if necessary. Refer to «Throttle Body Cleaning»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions__throttle-body-cleaning) .
Test the engine coolant temperature (ECT) sensor. Compare the scan tool ECT Sensor value to the intake air temperature (IAT) sensor value on a cold engine. The ECT and IAT Sensor values should be within 3°C (5°F). If the engine coolant temperature sensor is out of range with the intake air temperature sensor, test the resistance of the engine coolant temperature sensor. Refer to «Temperature Versus Resistance»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-specifications__temperature-versus-resistance) , for resistance specifications. Replace the engine coolant temperature sensor if the resistance is not within specification. Refer to «Engine Coolant Temperature Sensor Replacement»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions) . If the sensor is within the specifications, test the engine coolant temperature sensor circuits for high resistance.
Verify that the fuel system has adequate pressure for engine start-up. The fuel pump control module should command the fuel pump ON for 2 S when the ignition is turned to ON. Refer to «Fuel System Description»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-description-and-operation) , and «Fuel System Diagnosis»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-dtc-p0411-luk-to-dtc-p2635-and-symptom-troubleshooting-diagnosis) for correct fuel pressure specifications.
Inspect for excessive crankshaft endplay that will cause the crankshaft position sensor reluctor wheel to move out of alignment with the crankshaft position sensor. Refer to «Crankshaft and Bearing Cleaning and Inspection»(/buick/regal/v-2009-2013/remont/mechanical/#engine-mechanical-24l__crankshaft-and-bearing-cleaning-and-inspection) .

Hesitation, Sag, Stumble

Test the fuel pressure. Refer to «Fuel System Diagnosis»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-dtc-p0411-luk-to-dtc-p2635-and-symptom-troubleshooting-diagnosis) .
Inspect the mass air flow (MAF) sensor for obstruction, contamination, and damage. Refer to «Mass Airflow Sensor with Intake Air Temperature Sensor Replacement»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions) .
Test the generator. Refer to «Symptoms - Engine Electrical»(/buick/regal/v-2009-2013/remont/charging-system/#battery-charging-system-and-starting-system-non-hybrid__symptoms-engine-electrical) . Repair the charging system if the generator output voltage is less than 9 V or more than 16 V.
Test the manifold absolute pressure (MAP) sensor. Refer to «DTC P0106»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-dtc-p0010-to-dtc-p0411) .
Inspect for excessive crankshaft endplay that will cause the crankshaft position sensor reluctor wheel to move out of alignment with the crankshaft position sensor. Refer to «Crankshaft and Bearing Cleaning and Inspection»(/buick/regal/v-2009-2013/remont/mechanical/#engine-mechanical-24l__crankshaft-and-bearing-cleaning-and-inspection) .
Engine warm and idling, verify the correct operation of the camshaft actuator system. Command the intake and exhaust camshaft actuators from 0 degrees to 25 degrees and back to zero while observing the scan tool Intake Camshaft Position Variance and Exhaust Camshaft Position Variance parameters. Each parameter should be less than 2 degrees in each of the commanded states. If any of the parameters is greater than 2 degrees, inspect the suspect camshaft actuator and camshaft actuator solenoid valve and valve bore for contamination, obstruction, and damage. Refer to «Camshaft Actuator System Description»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-description-and-operation) ,, «Camshaft Position Exhaust Actuator Replacement»(/buick/regal/v-2009-2013/remont/mechanical/#engine-mechanical-24l) ,, and «Camshaft Position Intake Actuator Replacement»(/buick/regal/v-2009-2013/remont/mechanical/#engine-mechanical-24l) .

Lack of Power, Sluggishness, or Sponginess

Inspect the engine electrical system for correct operation. Refer to «Symptoms - Engine Electrical»(/buick/regal/v-2009-2013/remont/charging-system/#battery-charging-system-and-starting-system-non-hybrid__symptoms-engine-electrical) .
Verify that each injector harness is connected to the correct injector.
Inspect the mass air flow (MAF) sensor for obstruction, contamination, and damage. Refer to «Mass Airflow Sensor with Intake Air Temperature Sensor Replacement»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions) .
Engine warm and idling, verify the correct operation of the camshaft actuator system. Command the intake and exhaust camshaft actuators from 0 degrees to 25 degrees and back to zero while observing the scan tool Intake Camshaft Position Variance and Exhaust Camshaft Position Variance parameters. Each parameter should be less than 2 degrees in each of the commanded states. If any of the parameters is greater than 2 degrees, inspect the suspect camshaft actuator and camshaft actuator solenoid valve and valve bore for contamination, obstruction, and damage. Refer to «Camshaft Actuator System Description»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-description-and-operation) ,, «Camshaft Position Exhaust Actuator Replacement»(/buick/regal/v-2009-2013/remont/mechanical/#engine-mechanical-24l) ,, and «Camshaft Position Intake Actuator Replacement»(/buick/regal/v-2009-2013/remont/mechanical/#engine-mechanical-24l) .

Poor Fuel Economy

Inspect for heavy loads being carried or towed
Inspect for acceleration rate too much or too often
Inspect for incorrect operation of the speedometer.
Observe the scan tool Throttle Body Idle Airflow Compensation parameter. A value greater than 80% may indicate an excessive accumulation of deposits in the throttle bore. Inspect the throttle body and bore and clean, if necessary. Refer to «Throttle Body Cleaning»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions__throttle-body-cleaning) .
Verify that the engine coolant temperature (ECT) has not shifted in value. Allow the engine to run and reach operating temperature. Observe the ECT Sensor parameter with a scan tool and compare the reading to that parameter listed on the «Engine Control Module Scan Tool Information (LUK)»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-scan-tool-information-all-systems__engine-control-module-scan-tool-information) , «Engine Control Module Scan Tool Information (LEA)»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-scan-tool-information-all-systems__engine-control-module-scan-tool-information) , list. If the reading is not in the range specified in the list, test the resistance of the engine coolant temperature sensor. Refer to «Temperature Versus Resistance»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-specifications__temperature-versus-resistance) , for resistance specifications. Replace the engine coolant temperature sensor if the resistance is not within specification. Refer to «Engine Coolant Temperature Sensor Replacement»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions) . If the sensor is within the specification, test the engine coolant temperature sensor circuits for high resistance.
Inspect the mass air flow (MAF) sensor for obstruction, contamination, and damage. Refer to «Mass Airflow Sensor with Intake Air Temperature Sensor Replacement»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions) .
Inspect the brake system for brake drag.

Rough, Unstable, or Incorrect Idle and Stalling

Observe the scan tool Throttle Body Idle Airflow Compensation parameter. A value greater than 80% may indicate an excessive accumulation of deposits in the throttle bore. Inspect the throttle body and bore and clean, if necessary. Refer to «Throttle Body Cleaning»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions__throttle-body-cleaning) .
Inspect the mass air flow (MAF) sensor for obstruction, contamination, and damage. Refer to «Mass Airflow Sensor with Intake Air Temperature Sensor Replacement»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions) .
Inspect the engine mounts. Refer to «Engine Mount Inspection»(/buick/regal/v-2009-2013/remont/mechanical/#engine-mechanical-24l__engine-mount-inspection) .
Inspect the intake and exhaust manifolds for casting flash.

Surges/Chuggles

Verify that each injector harness is connected to the correct injector.
Inspect the mass air flow (MAF) sensor for obstruction, contamination, and damage. Refer to «Mass Airflow Sensor with Intake Air Temperature Sensor Replacement»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions) .
Inspect for slow responding heated oxygen sensors (HO2S). The heated oxygen sensors should respond quickly to a change in throttle position. If the heated oxygen sensors do not respond to different throttle positions, inspect for contamination from fuel, silicon, or the incorrect use of RTV sealant. The sensors may have a white powdery coating and result in a high, but false, signal voltage, which gives a rich exhaust indication. The engine control module reduces the amount of fuel delivered to the engine, causing a driveability condition. Refer to «DTC P0133, P0134, P013A, P013B, P013E, P013F, P0140, P1133, P2270, P2271, or P2A00»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-dtc-p0010-to-dtc-p0411) for additional information.

Perform the «Diagnostic System Check - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Schematic Reference

«Engine Controls Schematics (LEA)»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-wiring-schematic-diagrams) , «Engine Controls Schematics (LUK)»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-wiring-schematic-diagrams)
«Instrument Cluster Schematics»(/buick/regal/v-2009-2013/remont/gauges-instrument-panels/#instrument-panel-system-displays-and-gauges)

Connector End View Reference

Engine Controls Schematics (LEA) , Engine Controls Schematics (LUK)

Electrical Information Reference

«Circuit Testing»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

Note. Any MIL requesting DTCs that may be set should be diagnosed first.

Ignition ON, command the MIL ON and OFF with a scan tool. The MIL should turn ON and OFF as commanded.
Command the MIL ON and OFF with a scan tool while observing the following control circuit status parameters: The MIL Control Circuit Low Voltage Test Status The MIL Control Circuit Open Test Status The MIL Control Circuit High Voltage Test Status Each parameter should display OK or Not Run.
Engine running, command the MIL ON and OFF with a scan tool while observing the following control circuit status parameters: The MIL Control Circuit Low Voltage Test Status The MIL Control Circuit Open Test Status The MIL Control Circuit High Voltage Test Status Each parameter should display OK or Not Run.

Ignition OFF, disconnect the X1 harness connector at the K20 engine control module.
Ignition ON, the malfunction indicator lamp should not illuminate. If the malfunction indicator lamp is illuminated, test the malfunction indicator lamp control circuit terminal 46 X1 for a short to ground. If the circuit tests normal, replace the P16 instrument cluster.
Connect a 3 A fused jumper wire between the malfunction indicator lamp control circuit terminal 46 X1 and ground. The malfunction indicator lamp should illuminate. If the malfunction indicator lamp illuminates, replace the K20 engine control module. If the malfunction indicator lamp does not illuminate, test the malfunction indicator lamp control circuit terminal 46 X1 for a short to voltage or an open/high resistance. If the malfunction indicator lamp control circuit tests normal, test the instrument cluster ignition voltage circuit for a short to ground or open/high resistance. If the circuit tests normal, replace the P16 instrument panel cluster/bulb.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

«Instrument Cluster Replacement»(/buick/regal/v-2009-2013/remont/gauges-instrument-panels/#instrument-panel-system-displays-and-gauges)
«Control Module References»(/buick/regal/v-2009-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for replacement, setup, and programming.

Perform the «Diagnostic System Check - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Description

The purpose of the evaporative emission (EVAP) Service Bay Test is to aid in resetting the EVAP inspection/maintenance system status. For this vehicle that is equipped with the engine off natural vacuum diagnostic, the Service Bay Test uses the scan tool to initiate the engine control module (ECM) regular sequence of EVAP system DTC tests, but with different enable criteria. By using the Service Bay Test the inspection/maintenance indicator can be set without the need for multiple cold soaks.

The scan tool displays for the Service Bay Test are based on the events that occur within the following three categories

The engine running portion of the tests-The vehicle must remain at rest, in Park, or in Neutral, during this portion of the test. This test inspects for large leaks, a leaking purge valve and/or vent system restrictions. The scan tool will display test progress or the reason for an abort or failure.
Drive cycle-The scan tool will display time and distance needed to warm the fuel.
Ignition OFF-During this portion of the test, the engine controller will remain active for up to 45 minutes when the ignition is turned OFF to allow control of the EVAP canister vent valve and run the engine off natural vacuum test. The engine controller inspects for small leaks during this period by monitoring fuel tank pressure or vacuum. If the system is sealed, there will be a pressure or vacuum change. Pressure or vacuum changes that are less than the calibrated values indicate a leak.

When the EVAP diagnostics are initiated by the Service Bay Test, the scan tool will indicate if the enable conditions listed below are not met, or will display a specific reason if the test aborts. When complete, the display will indicate that the tests passed or failed.

Conditions for Running the Test

The following conditions must be met in order to enable the Service Bay Test

The battery voltage is between 11-18V.
The engine coolant temperature (ECT) is less than 35°C (95°F) at start-up.
The EVAP inspection/maintenance system status indicator is set to NO.
The fuel level is 15-85 percent capacity and cannot be refueled during the tests.
There are no DTCs displayed.
The vehicle must be driven for the time and distance specified on the scan tool.
The ambient air temperature is between 0-40°C (32-104°F).
The ignition must remain OFF during the engine OFF portion of the test, and the vehicle must remain at rest.

Test Procedure

Note. If the Service Bay Test aborts or fails, a DTC will NOT be set.

Install a scan tool.
Select the Service Bay Test with the scan tool.
Follow the instructions on the scan tool. If the test aborts, correct the condition for running the test, then retest. If the test fails, repair the vehicle for the condition indicated by the failure message on the scan tool.
Verify that the EVAP inspection/maintenance system status is set to YES.

Perform the «Diagnostic System Check - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

This Engine Cranks but Does Not Run diagnostic is an organized approach to identify a condition which causes the engine to crank but not start. This diagnostic directs the technician to the appropriate system diagnosis.

Inspect for any of the following conditions

When attempting to start the engine, the mechanical portion of the vehicle key must be locked in the fully extended position with the fob parallel to the key. Leaving the key partially retracted or folded over when starting may interrupt transponder authentication and result in an intermittent no-start condition. In such instances, DTC B3055 may also be set. If an intermittent no-start complaint is received, it may be necessary to discuss with the customer their starting habits and verify they are locking the key in the fully extended position, fob parallel to the key, before starting.
The engine control module (ECM) uses the camshaft position sensors to determine engine speed and position when there is a crankshaft position sensor condition.
The engine will operate with a crankshaft position sensor condition only if the ECM has stored the learned reference position of the camshafts in memory. With a crankshaft position sensor condition in the signal circuit, the engine will go into a limp home mode after a hard restart. The ECM then calculates engine speed from one of the camshaft position sensors.
The fuel pump flow control module controls and monitors the operation of the in-tank fuel pump. If the fuel pump flow control module detects a fault, a DTC sets in the fuel pump flow control module. The fuel pump flow control module will then send a serial data message to the engine control module (ECM) requesting the illumination of the malfunction indicator lamp (MIL).
Insufficient fuel can cause a no start condition. Thoroughly inspect the fuel delivery system for sufficient fuel volume to the fuel injectors. Inspect the fuel supply components for partial blockage or restrictions.
The fuel injectors are calibrated to begin operating when the fuel rail pressure reaches 7 MPa (101.5 psi) at 20-32°C (68-90°F). This specification will vary when the temperature is outside of this range.
Fuel injectors with partially blocked and restricted nozzles, or a malfunctioning solenoid, can cause a no start condition. Refer to «Fuel Injector Solenoid Coil Test»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-dtc-p0411-luk-to-dtc-p2635-and-symptom-troubleshooting-diagnosis) .
There may be fuel spray at the fuel injectors and the indicated fuel pressure may be correct, yet there may not be enough fuel to start the engine. If the fuel injectors and the injector circuit are OK, and fuel spray is detected, the fuel injector ON time may be inadequate. If the engine control module (ECM) receives incorrect inputs from the various information sensors, the fuel delivered by the fuel injectors may be inadequate to start the engine. Check all the engine data parameters with a scan tool and compare the values indicated with the expected values or the values from a known good vehicle.
Inspect the engine for good secure electrical grounds.
Water or foreign material in the fuel can cause a no start or engine will not stay running condition. During freezing weather water can freeze inside the fuel system. The engine may start after 30 min in a heated repair shop. The malfunction may not recur until parked overnight in freezing temperatures. Extreme weather conditions can cause contaminated fuel to prevent the vehicle from starting.
A vehicle that starts and runs after being brought to the repair shop for a no start condition, may have an ignition system that is susceptible to moisture. Spray water on the ignition system components and the wiring in order to check for an engine starting or will not stay running concern.

Schematic Reference

Connector End View Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Special Tools

«J 26792»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-special-tools-and-equipment__special-tools-diagnostic-tools) HEI Spark Tester
«CH-48027»(/buick/regal/v-2009-2013/remont/mechanical/#engine-mechanical-24l) Digital Pressure Gauge
For equivalent regional tools, refer to «Special Tools (Diagnostic Tools)»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-special-tools-and-equipment__special-tools-diagnostic-tools) .

Note. This diagnostic assumes the following: The battery is completely charged. The engine cranking speed is acceptable. There is adequate fuel in the fuel tank.

Engine cranking, observe the DTC information with a scan tool. Verify that DTC P0116, P0117, P0335, P0336, P0513, P0601-P0604, P0606, P062B, P0627-P0629, P0633, P069E, P1631, P1649, or U0109 does not set. If any of the listed DTCs are set, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) .
Ignition ON, observe the Security Indicator on the instrument cluster. The security indicator should illuminate momentarily. If the security indicator stays ON or is flashing, review the scan tool DTC information for Immobilizer system DTCs-Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) . For more information concerning the Immobilizer system, refer to «Immobilizer Description and Operation»(/buick/regal/v-2009-2013/remont/door-locks-anti-theft-systems/#immobilizer-system__immobilizer-description-and-operation) .
Engine cranking, observe the scan tool Engine Speed parameter. The parameter value should indicate an engine speed greater than 0 RPM. If the engine speed is 0 RPM, refer to «DTC P0335 or P0336»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-dtc-p0010-to-dtc-p0411) for further diagnosis.
Engine cranking, observe the scan tool Mass Airflow Sensor parameter. The parameter should display greater than 0 Hz. If the parameter is not the specified value, refer to «DTC P0102 or P0103 (With LEA)»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-dtc-p0010-to-dtc-p0411) , «DTC P0102 or P0103 (With LUK)»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-dtc-p0010-to-dtc-p0411) for further diagnosis.
Test the ignition system for spark. Refer to «Electronic Ignition System Diagnosis»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-dtc-p0411-luk-to-dtc-p2635-and-symptom-troubleshooting-diagnosis) .
Ignition OFF, all accessories OFF, install a «CH-48027»(/buick/regal/v-2009-2013/remont/mechanical/#engine-mechanical-24l) Digital Pressure Gauge -Refer to «Fuel Pressure Gauge Installation and Removal»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions) .
Ignition ON, engine OFF, command the Fuel Pump Enable ON with a scan tool. Verify the fuel pressure is between 345-690 kPa (50-100 psi) while the fuel pump is running. If the fuel pump runs but the pressure is not the specified value, refer to «Fuel System Diagnosis»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-dtc-p0411-luk-to-dtc-p2635-and-symptom-troubleshooting-diagnosis) . If the fuel pump does not run, refer to «Fuel Pump Electrical Circuit Diagnosis»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-dtc-p0411-luk-to-dtc-p2635-and-symptom-troubleshooting-diagnosis) .
Verify the fuel pressure after the pump is turned OFF, decreases to 500-599 kPa (72-87 psi) and does not decrease greater than 34 kPa (5 psi) in 1 minute from that point. If not the specified value, refer to «Fuel System Diagnosis»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-dtc-p0411-luk-to-dtc-p2635-and-symptom-troubleshooting-diagnosis) .
Verify that the following conditions do not exist: Collapsed air intake duct to the throttle body Restricted air filter element Gas or coolant fouled spark plugs A skewed engine coolant temperature (ECT) sensor-Refer to «Temperature Versus Resistance»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-specifications__temperature-versus-resistance) . Restricted exhaust system-Refer to «Restricted Exhaust»(/buick/regal/v-2009-2013/remont/exhaust/#engine-exhaust-system) . Contaminated fuel-Refer to «Alcohol/Contaminants-in-Fuel Diagnosis»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-dtc-p0411-luk-to-dtc-p2635-and-symptom-troubleshooting-diagnosis) . An engine mechanical condition, for example, worn timing chain and gears, low compression-Refer to «Symptoms - Engine Mechanical»(/buick/regal/v-2009-2013/remont/mechanical/#engine-mechanical-24l) . If you find any of the above conditions, repair as necessary.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Perform the «Diagnostic System Check - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provide an overview of each diagnostic category.

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
Fuel Pump High Signal	P0231	P023F	P0232	P023F, P2635
Fuel Pump Low Signal		P023F		P023F, P2635

The engine control module (ECM) supplies voltage to the fuel pump control module when the ECM detects that the ignition is on. The voltage from the ECM to the fuel pump control module remains active for two seconds, unless the engine is in crank or run. While this voltage is being received, the fuel pump control module closes the ground switch of the fuel pump and also supplies a varying voltage to the fuel tank pump module in order to maintain the desired fuel rail pressure.

Schematic Reference

Engine Controls Schematics (LEA) , Engine Controls Schematics (LUK)

Connector End View Reference

Description and Operation

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Ignition ON, command the fuel pump ON and OFF using the scan tool ECM output control. The fuel pump should turn on and off.

Ignition OFF, disconnect the harness connector at the G12 fuel pump.
Connect a test lamp between the control circuit terminal 1 and ground.
Ignition ON, command the G12 fuel pump ON and OFF using a scan tool ECM fuel pump output control. The test lamp should turn ON and OFF, as commanded. If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the K27 fuel pump control module. If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K27 fuel pump control module.
Ignition OFF, connect a test lamp between the control circuit terminal 1 and the low reference circuit terminal 2.
Ignition ON, command the G12 fuel pump ON using a scan tool. The test lamp should illuminate. If the test lamp does not illuminate, test the low reference circuit terminal 1 for a short to voltage or an open/high resistance. If the circuit tests normal, replace the K27 fuel pump control module.
If all circuits test normal, replace the G12 fuel pump.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for fuel pump control module replacement, setup, and programming

Perform the «Diagnostic System Check - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The engine control module (ECM) supplies voltage to the fuel pump control module when the ECM detects that the ignition is ON. The voltage from the ECM to the fuel pump control module remains active for 2 s, unless the engine is in Crank or Run. While this voltage is being received, the fuel pump control module closes the ground switch of the fuel tank fuel pump module and also supplies a varying voltage to the fuel tank fuel pump module in order to maintain the desired fuel line pressure.

The fuel system is an electronic returnless on-demand design. A returnless fuel system reduces the internal temperature of the fuel tank by not returning hot fuel from the engine to the fuel tank. Reducing the internal temperature of the fuel tank results in lower evaporative emissions.

An electric turbine style fuel pump attaches to the fuel tank fuel pump module inside the fuel tank. The fuel pump supplies fuel through the fuel feed pipe to the high pressure fuel pump. The high pressure fuel pump supplies fuel to a variable-pressure fuel rail. Fuel enters the combustion chamber through precision multi-hole fuel injectors. The high pressure fuel pump, fuel rail pressure, fuel injection timing, and injection duration are controlled by the engine control module (ECM).

The fuel injectors are calibrated to begin operating at 0.7 Mpa (101.5 psi) at 20-32°C (68-90°F). This specification will vary when the temperature is outside of this range.

Description and Operation

Engine Controls Schematics (LEA) , Engine Controls Schematics (LUK)

Electrical Information Reference

«Circuit Testing»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

Special Tools

CH-48027 Digital Pressure Gauge
J 37287 Fuel Line Shut-Off Adapter

Note. Repair all fuel system related DTCs before performing this diagnostic. Inspect the fuel system for damage or external leaks before proceeding. Verify that adequate fuel is in the fuel tank before proceeding. The Fuel Pump Enable may need to be commanded ON a few times in order to obtain the highest possible fuel pressure. Before proceeding with this test, review the User Manual CH 48027-5 for Safety Information and Instructions.

Ignition OFF, all accessories OFF, install a CH-48027 Gauge.
Ignition ON, engine OFF, command the Fuel Pump Enable ON with a scan tool. Verify the fuel pressure is between 345-690 kPa (50-100 psi) with the fuel pump running.
Engine idling at normal operating temperature, the Fuel Pump Flow Control Module Fuel Pressure Sensor parameter should read between 300-400 kPa (43-58 psi).

Ignition ON, engine OFF, command the Fuel Pump Enable ON with a scan tool and observe the fuel pressure gauge while the fuel pump is operating. Verify the fuel pressure is between 345-690 kPa (50-100 psi). If the fuel pressure is greater than the specified range, replace the fuel tank fuel pump module. If the fuel pressure is less than the specified range, test, inspect, and repair the items listed below. If all items test normal, replace the fuel tank fuel pump module. Restricted fuel feed pipe Inspect the harness connectors and the ground circuits of the fuel tank fuel pump module for poor connections.
Verify that the fuel pressure, after the fuel pump is turned off, decreases to 500-599 kPa (72-87 psi), and does not decrease more than 34 kPa (5 psi) in 1 minute from that point. If the fuel pressure stays above 600 kPa (87 psi), replace the fuel tank fuel pump module. If the fuel pressure decreases more than the specified value, perform the following procedure: Ignition OFF, relieve the fuel pressure. Refer to «Fuel Pressure Relief»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions__fuel-pressure-relief) . Disconnect the chassis fuel feed hose from the engine compartment fuel pipe. Install the J 37287 Adapter between the chassis fuel hose and the engine compartment fuel pipe. Open the valve on the J 37287 Adapter. Ignition ON, command the Fuel Pump Enable ON with a scan tool and bleed the air from the CH-48027 Gauge. Command the Fuel Pump Enable ON and then OFF with a scan tool. Close the valve on the J 37287 Adapter. Monitor the fuel pressure for 1 min. If the fuel pressure decreases more than 34 kPa (5 psi) within the specified time, locate and replace the leaking fuel injector(s). If the fuel pressure does not decrease more than 34 kPa (5 psi) within the specified time, replace the fuel tank fuel pump module.
Relieve the fuel pressure to 69 kPa (10 psi). Verify that the fuel pressure does not decrease greater than 14 kPa (2 psi) in 5 min. If the fuel pressure decreases greater than the specified value, replace the fuel tank fuel pump module.
Operate the vehicle within the conditions of the customer's concern while monitoring the fuel pressure with the CH-48027 Gauge. The fuel pressure should not drop off during acceleration, cruise, or hard cornering. If the fuel pressure drops off, test, inspect, and repair the items listed below. If all items test normal, replace the fuel tank fuel pump module. Restricted fuel feed pipe Inspect the harness connectors and the ground circuits of the fuel tank fuel pump module for poor connections.
If the fuel system tests normal, refer to «Symptoms - Engine Controls»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-dtc-p0411-luk-to-dtc-p2635-and-symptom-troubleshooting-diagnosis) ,, «Fuel Injector Solenoid Coil Test»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-dtc-p0411-luk-to-dtc-p2635-and-symptom-troubleshooting-diagnosis) ,, and «Fuel Injector Balance Test»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-dtc-p0411-luk-to-dtc-p2635-and-symptom-troubleshooting-diagnosis) .

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

«Direct Fuel Injector Replacement»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions)
«Fuel Feed Pipe Replacement»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions)
«Fuel Pump Fuel Feed Hose Replacement»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions)
«Fuel Tank Fuel Pump Module Replacement (NT7)»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions) , «Fuel Tank Fuel Pump Module Replacement (NU6)»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions)

Perform the «Diagnostic System Check - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The engine control module (ECM) supplies a separate high voltage supply circuit and a high voltage control circuit for each fuel injector. The injector high voltage supply circuit and the high voltage control circuit are both controlled by the ECM. The ECM energizes each fuel injector by grounding the control circuit. The ECM controls each fuel injector with 65 V. This is controlled by a boost capacitor in the ECM. During the 65 V boost phase, the capacitor is discharged through the injector high voltage supply circuit, allowing for initial injector opening. The injector is then held open with 12 V. A fuel injector coil winding resistance that is too high or too low will affect the engine driveability. The fuel injector coil windings are affected by temperature. The resistance of the fuel injector coil windings will increase as the temperature of the fuel injector increases.

Schematic Reference

Electrical Information Reference

«Circuit Testing»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Note. The resistance test must be performed at the fuel injector or mis-diagnosis will occur. The DMM and test leads must be calibrated to 0 ohms in order to prevent mis-diagnosis.

Remove the intake manifold and disconnect the appropriate Q17 fuel injector.
Test for 1.9-2.3 ohms at 20°C (68°F) between the high voltage supply circuit terminal 2 and the high voltage control circuit terminal 1 at the fuel injector. If not within the specified range, replace the Q17 fuel injector.
Measure the resistance between each terminal at the Q17 fuel injector and the Q17 fuel injector housing/case. The DMM should display OL ohms. If less than the specified value, replace the Q17 fuel injector.
If the injectors measure OK, perform the Fuel Injector Balance Test. Refer to «Fuel Injector Balance Test»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-dtc-p0411-luk-to-dtc-p2635-and-symptom-troubleshooting-diagnosis) .

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Direct Fuel Injector Replacement

Perform the «Diagnostic System Check - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The fuel injector balance test is performed while the engine is running at idle. The scan tool pressurizes the fuel rail to a predetermined pressure before each injector is pulsed for a precise amount of time allowing a measured amount of the fuel to be injected. This causes a drop in the system fuel pressure that is recorded and used to compare each injector.

Monitoring the Current Misfire Counters may help to isolate the fuel injector that is causing the condition.
Operating the vehicle over a wide temperature range may help isolate the fuel injector that is causing the condition.

Note. DO NOT perform this test if the engine coolant temperature (ECT) is above 60°C (140°F). Irregular fuel pressure readings may result due to hot soak fuel boiling. Verify that adequate fuel is in the fuel tank before proceeding with this diagnostic.

Fuel Injector Balance Test

Verify the correct low side fuel pressure. Refer to «Fuel System Diagnosis»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-dtc-p0411-luk-to-dtc-p2635-and-symptom-troubleshooting-diagnosis) .
Engine idling at normal operating temperature, observe the Fuel Rail Pressure Sensor parameter with a scan tool. The pressure should be approximately 3 MPa (435 psi).
Engine running at normal operating temperature. With a scan tool, select the Fuel Injector Balance function within the Output Controls menu.
Select and test an injector. Repeat for each injector in order to obtain a pressure drop value for each injector.
After all injectors are tested, record the fuel pressure drops.
Add all of the individual pressure drop values except for the injector suspected of being faulty. This is the total pressure drop.
Divide the total pressure drop by the number of fuel injectors that were added together. This is the average pressure drop.
Multiply the average pressure drop by 0.20. This is the acceptable variance from the average pressure drop, 20 percent. If the difference between any individual pressure drop and the average pressure drop is more than the acceptable variance, replace the fuel injector.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Direct Fuel Injector Replacement

Perform the «Diagnostic System Check - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Test Description

Water contamination in the fuel system may cause driveability conditions such as hesitation, stalling, no start, or misfires in one or more cylinders. Water may collect near a single fuel injector at the lowest point in the fuel injection system and cause a misfire in that cylinder. If the fuel system is contaminated with water, inspect the fuel system components for rust or deterioration.

Ethanol concentrations of greater than 10 percent in nonblended gasoline or greater than 85 percent with E85 blended gasoline for flexible fuel applications can cause driveability conditions such as hesitation, lack of power, stalling, or no start. Excessive concentrations of ethanol used in vehicles not designed for it may cause fuel system corrosion, deterioration of rubber components, and fuel filter restriction.

Special Tools

J 44175 Fuel Composition Tester

System Verification

The fuel sample should be drawn from the bottom of the tank so that any water present in the tank will be detected. The sample should be bright and clear.

If the sample appears cloudy, or contaminated with water, as indicated by a water layer at the bottom of the sample, perform the Particulate Contaminants in Fuel Testing Procedure.
If alcohol contamination is suspected, perform the Alcohol in Fuel Testing procedure.

Alcohol in Fuel Testing with Special Tool

Test the fuel composition using J 44175 Tester and Instruction Manual.
If water appears in the fuel sample, clean the fuel system.
Subtract 50 from the reading on the DMM in order to obtain the percentage of alcohol in the fuel sample.
If the nonblended gasoline fuel sample measures more than 15 percent ethanol, or if the E85 blended gasoline fuel sample measures more than 91 percent ethanol, add fresh regular gasoline to the vehicle's fuel tank.
Test the fuel composition.
If additional testing indicates that the ethanol percentage is still above 15 percent for a nonblended gasoline sample, drain and replace the vehicle's fuel. Refer to «Fuel Tank Draining (Non E-85)»(/buick/regal/v-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions__fuel-tank-draining-non-e-85) . If additional testing indicates that the E85 blended gasoline sample still measures above 91 percent, continue adding fresh, regular gasoline until the ethanol content is 85 percent or less.

Alcohol in Fuel Testing without Special Tool

Using a 100 ml (3.38 oz) specified cylinder with 1 ml (0.034 oz) graduation marks, fill the cylinder with fuel to the 90 ml (3.04 oz) mark.
Add 10 ml (0.34 oz) of water in order to bring the total fluid volume to 100 ml (3.38 oz) and install a stopper.
Shake the cylinder vigorously for 10-15 seconds.
Carefully loosen the stopper in order to release the pressure.
Re-install the stopper and shake the cylinder vigorously again for 10-15 seconds.
Put the cylinder on a level surface for approximately 5 minutes in order to allow adequate liquid separation. If alcohol is present in the fuel, the volume of the lower layer, which would now contain both alcohol and water, will be more than 10 ml (0.34 oz). For example, if the volume of the lower layer is increased to 15 ml (0.51 oz), this indicates at least 5 percent alcohol in the fuel. The actual amount of alcohol may be somewhat more because this procedure does not extract all of the alcohol from the fuel.

Particulate Contaminants in Fuel Testing Procedure

Using an approved fuel container, draw approximately 0.5 liter (0.53 qt) of fuel.
Place the container on a level surface for approximately 5 minutes in order to allow settling of the particulate contamination. Particulate contamination will show up in various shapes and colors. Sand will typically be identified by a white or light brown crystals. Rubber will appear as black and irregular particles.
Observe the fuel sample. If any physical contaminants or water are present, clean the fuel system.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Fuel System Cleaning

Perform the «Diagnostic System Check - Vehicle»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/regal/v-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provide an overview of each diagnostic category.

The ignition system uses individual ignition coil/module assemblies for each cylinder. The engine control module (ECM) controls the individual coils by transmitting timing pulses on the ignition control circuit of each ignition coil/module to enable a spark event.

Depending on location in the spliced ignition voltage circuit, a slight resistance can cause a misfire or a crank/no start concern. A voltage drop test will pinpoint this condition.
A slight to moderate resistance on any ignition control circuit can cause a misfire before DTC P0351-P0354 sets.
Extended engine cranking time, may foul the spark plugs with excessive fuel.

Schematic Reference

Engine Controls Schematics (LEA) , Engine Controls Schematics (LUK)

Connector End View Reference