Engine Control System & Fuel System - 4.6l - DTC p0340 to DTC p2138 Cadillac DTS I

Diagnostic Instructions

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provide an overview of each diagnostic category.

Diagnostic Fault Information

Circuit/System Description

The 4X camshaft position (CMP) sensor circuits consist of an engine control module (ECM) supplied 5-volt reference circuit, low reference circuit, and an output signal circuit. The CMP sensor is an internally magnetic biased digital output integrated circuit sensing device. The sensor detects magnetic flux changes of the teeth and slots of a 4-tooth reluctor wheel attached to the camshaft. As each reluctor wheel tooth rotates past the CMP sensor, the resulting change in the magnetic field is used by the sensor electronics to produce a digital output pulse. The sensor returns a digital ON/OFF DC voltage pulse of varying frequency, with 4 varying width output pulses per camshaft revolution that represent an image of the camshaft reluctor wheel. The frequency of the CMP sensor output depends on the velocity of the camshaft. The ECM decodes the narrow and wide tooth pattern to identify camshaft position. This information is then used to determine the optimum ignition and injection points of the engine. The ECM also uses CMP sensor output information to determine the camshaft relative position to the crankshaft, to control camshaft phasing, and for limp-home operation.

Conditions for Running the DTC

1. DTC P0641 or P0651 is not set.
2. The engine is cranking or running.
3. The DTCs run continuously when the above conditions are met.

Conditions for Setting the DTC

P0340

1. The ECM detects that the starter is commanded on and the engine has been cranking for more than 4 seconds without a CMP sensor pulse. OR
2. The ECM detects that the engine has started, but did not received a CMP sensor pulse during the first engine revolution. OR
3. The ECM detects that the engine is running, but does not receive a CMP sensor pulse for 800 of 1000 engine cycles.

Action Taken When the DTC Sets

DTC P0340 is a Type B DTC.

Conditions for Clearing the MIL/DTC

DTC P0340 is a Type B DTC.

Diagnostic Aids

Inspect the 10-way engine harness to fuel injector harness connector, the CMP sensor connector, and the ECM connector for corrosion.

Reference Information

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-poor)
4. «Wiring Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

1. Ignition OFF, inspect the engine wiring harness carrying the CMP sensor circuits for the following conditions: Close routing of aftermarket electrical equipment Close to solenoids, motors, and relays Correct any wire harness routing or component placement conditions, if it is determined to be a possible source of electrical interference.
2. Start the engine. Using the Live Plot function on the scan tool, select the CMP parameter. Change the minimum spec to 400 ROMP and the maximum spec to 4,000 RPM. Select the CKP sensor parameter. Change the minimum spec to 600 RPM, and the maximum spec to 3,300 RPM.
3. Observe the scan tool.
4. Quickly accelerate and release the accelerator pedal several times. Do not accelerate past 3,200 RPM. The graphed lines on the Live Plot display should track together across the screen. If the vehicle passes the Circuit/System Verification test, operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that are captured in the Freeze Frame/Failure Records data list.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the CMP sensor.
2. Test for less than 1 ohm of resistance between the CMP low reference circuit terminal B and ground. If greater than the specified value, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
3. Ignition ON, test for 4.8-5.2 volts between the CMP 5-volt reference circuit terminal A and ground. If less than the specified range, test the 5-volt reference circuit for an open/high resistance or short to ground. If the circuit tests normal, replace the ECM. If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the ECM.
4. Ignition ON, test for 4.8-5.2 volts between the CMP signal circuit terminal C and ground. If less than the specified range, test the signal circuit for an open/high resistance or short to ground. If the circuit tests normal, replace the ECM. If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the ECM.
5. Ignition OFF, connect a fused jumper wire to the CMP signal circuit terminal C.
6. Ignition ON, momentarily touch the other end of the fused jumper wire to the battery negative post. The CMP Active counter parameter should increment. If the CMP active counter increments, replace the CMP sensor. If the CMP active counter does not increment, replace the ECM.

Component Testing

1. Inspect the CMP sensor for correct installation. Remove the CMP sensor from the engine and inspect the sensor O-ring for damage. If the sensor is loose, incorrectly installed, or damaged, replace the CMP sensor.
2. Connect the CMP sensor harness connector to the CMP sensor.
3. Ignition ON, engine OFF, observe the CMP Active counter parameter on the scan tool.
4. Pass a flat steel object across the tip of the sensor repeatedly. The CMP Active counter parameter should increment with each pass of the steel object. If the parameter does not increment, replace the CMP sensor.

Repair Procedures

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Camshaft Position Sensor Replacement»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2)
2. «Control Module References»(/cadillac/dts/i-2005-2011/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provide an overview of each diagnostic category.

The 4X camshaft position (CMP) sensor circuits consist of an engine control module (ECM) supplied 5-volt reference circuit, low reference circuit, and an output signal circuit. The CMP sensor is an internally magnetic biased digital output integrated circuit sensing device. The sensor detects magnetic flux changes of the teeth and slots of a 4-tooth reluctor wheel attached to the camshaft. As each reluctor wheel tooth rotates past the CMP sensor, the resulting change in the magnetic field is used by the sensor electronics to produce a digital output pulse. The sensor returns a digital ON/OFF DC voltage pulse of varying frequency, with 4 varying width output pulses per camshaft revolution that represent an image of the camshaft reluctor wheel. The frequency of the CMP sensor output depends on the velocity of the camshaft. The ECM decodes the narrow and wide tooth pattern to identify camshaft position. This information is then used to determine the optimum ignition and injection points of the engine. The ECM also uses CMP sensor output information to determine the camshaft relative position to the crankshaft, to control camshaft phasing, and for limp-home operation.

1. DTC P0641 or P0651 is not set.
2. The engine is cranking or running.
3. The DTCs run continuously when the above conditions are met.

1. The ECM detects that the engine has started, but has received either of the following during the first engine revolution: Less than or more than 4 CMP sensor pulses, if equipped with an automatic transmission less than 4 or more than 6 CMP sensor pulses, if equipped with a manual transmission OR
2. The ECM detects that the engine is running, but receives less than 397 CMP or more than 403 CMP sensor pulses per 100 engine cycles in 800 of 1000 engine cycles.

DTC P0341 is a Type B DTC.

DTC P0341 is a Type B DTC.

Inspect the 10-way engine harness to fuel injector harness connector, the CMP sensor connector, and the ECM connector for corrosion.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-poor)
4. «Wiring Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

1. Ignition OFF, inspect the engine wiring harness carrying the CMP sensor circuits for the following conditions: Close routing of aftermarket electrical equipment Close to solenoids, motors, and relays Correct any wire harness routing or component placement conditions, if it is determined to be a possible source of electrical interference.
2. Start the engine. Using the Live Plot function on the scan tool, select the CMP parameter. Change the minimum spec to 400 ROMP and the maximum spec to 4,000 RPM. Select the CKP sensor parameter. Change the minimum spec to 600 RPM, and the maximum spec to 3,300 RPM.
3. Observe the scan tool.
4. Quickly accelerate and release the accelerator pedal several times. Do not accelerate past 3,200 RPM. The graphed lines on the Live Plot display should track together across the screen. If the vehicle passes the Circuit/System Verification test, operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that are captured in the Freeze Frame/Failure Records data list.

1. Ignition OFF, inspect the CMP sensor for correct installation. If the CMP sensor is loose, inspect the sensor and the O-ring for damage. Replace as necessary.
2. Inspect the engine for the following conditions: Engine oil for debris Camshaft reluctor wheel for damage The timing chain, timing chain tensioner, and sprockets for wear or damage If debris is found in the engine oil, inspect the internal engine components to determine the root cause. Repair or replace any worn or damaged components.

1. Inspect the CMP sensor for correct installation. Remove the CMP sensor from the engine and inspect the sensor O-ring for damage. If the sensor is loose, incorrectly installed, or damaged, replace the CMP sensor.
2. Connect the CMP sensor harness connector to the CMP sensor.
3. Ignition ON, engine OFF, observe the CMP Active counter parameter on the scan tool.
4. Pass a flat steel object across the tip of the sensor repeatedly. The CMP Active counter parameter should increment with each pass of the steel object. If the parameter does not increment, replace the CMP sensor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Camshaft Position Sensor Replacement»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2)
2. «Control Module References»(/cadillac/dts/i-2005-2011/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The ignition system on this engine uses an individual module/coil for each cylinder. The engine control module (ECM) controls the spark event for each cylinder through the 8 individual ignition control (IC) circuits. When the ECM commands the IC circuit ON, electrical current will flow through the primary winding of the ignition coil, creating a magnetic field. When a spark event is requested, the ECM will command the IC circuit OFF, interrupting current flow through the primary winding. The magnetic field created by the primary winding will collapse across the secondary coil windings, producing a high voltage across the spark plug electrodes. The ECM uses information from the crankshaft position (CKP) sensor, and the camshaft position (CMP) sensor for sequencing and timing of the spark events. The ECM monitors each IC circuit for improper voltage levels. Each ignition module/coil assembly has the following electrical circuits

1. An ignition voltage circuit
2. A ground
3. An IC control circuit
4. A low reference circuit

1. The engine is running.
2. DTCs P0351-P0358 runs continuously when the above condition is met.

The ECM detects one of the following failures on the IC circuit for up to 6 seconds

1. An open
2. A short to ground
3. A short to voltage

DTCs P0351-P0358 are Type B DTCs.

DTCs P0351-P0358 are Type B DTCs.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-poor)
4. «Wiring Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

1. Start and run the engine.
2. With a scan tool, monitor that all eight ignition control (IC) circuit status parameters display OK.
3. Observe the Misfire Current counters using the scan tool. The counters should not be incrementing
4. 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.

1. Turn OFF the ignition.
2. Disconnect the ECM.
3. Test the affected IC circuit for an open, a high resistance, a short to ground, and a short to voltage. If a fault is found, repair the circuit as needed.
4. Connect the ECM.
5. Exchange the affected ignition coil/module with the ignition/coil module of a good cylinder.
6. Start the engine and observe the scan tool. If the DTC or the misfire transfers with the suspect ignition/coil module, replace as needed. If the DTC or the misfire does not transfer with the suspect ignition/coil module, replace the ECM.

1. «Ignition Coil Replacement - Bank 1»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2) , «Ignition Coil Replacement - Bank 2»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2)
2. «Control Module References»(/cadillac/dts/i-2005-2011/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, setup, and programming

Repair Verification

If the customer concern was a flashing MIL, perform the following procedure

1. Install any components or connectors that have been removed or replaced during diagnosis.
2. Perform any adjustment, programming, or setup procedures that are required when a component or module is removed or replaced.
3. Clear the DTCs.
4. Turn OFF the ignition for 60 seconds.
5. 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»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-trouble-code-dtc-list) and perform the appropriate diagnostic procedure.
6. To verify that the performance of the catalytic converter has not been affected by the condition that set this DTC, perform the Repair Verification for DTC P0420. Refer to «DTC P0420»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-dtc-p0340-to-dtc-p2138) .

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provide an overview of each diagnostic category.

The engine control module (ECM) tests the exhaust gas recirculation (EGR) system during deceleration. The ECM does this by momentarily commanding the EGR valve to open while monitoring the signal circuit of the manifold absolute pressure (MAP) sensor. When the EGR valve is opened, the ECM will expect to see a predetermined increase in MAP. If the expected increase in MAP is not detected, the ECM records the amount of MAP difference that was detected and adjusts a calibrated fail counter towards a calibrated fail threshold level. The number of EGR flow test counts required to exceed the fail threshold may vary according to the amount of detected EGR flow error.

The EGR valve position sensor is monitored by the control module. The 5-volt reference circuit, the low reference circuit, and the EGR valve position signal circuit are used by the control module to determine the EGR valve position. The control module compares the EGR Position Sensor parameter with the desired EGR Position parameter when the valve is commanded open or closed.

The control module controls the EGR valve with a solid state device called a driver. The driver supplies the EGR solenoid with 12 volts that is pulse width modulated (PWM) through the EGR solenoid high control circuit. A ground path is provided by the control module through the EGR solenoid low control circuit. The driver has the ability to detect an electrical malfunction on the EGR solenoid control circuits.

When the ignition switch is turned ON, the control module records the EGR Learned Minimum Position. The control module compares the EGR Learned Minimum Position parameter to the EGR Position Sensor parameter.

Normally, the ECM will only allow one EGR flow test during an ignition cycle. To aid in verifying a repair, the ECM will allow up to 27 EGR flow test counts during the first ignition cycle following a code clear event. Between 8-14 EGR flow test counts should be sufficient for the ECM to determine adequate EGR flow and pass the EGR flow test. If the ECM detects an EGR flow error, DTC P0401 sets.

1. DTCs P0016, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0122, P0123, P0128, P0201, P0202, P0203, P0204, P0205, P0206, P0207, P0208, P0220, P0222, P0223, P0300, P0301-P0308, P0315, P0335, P0336, P0340, P0341, P0403, P0404, P0502, P0503, P0601, P0602, P0603, P0604, P0606, P060D, P062F, P0641, P0651, P1404, P2135 are not set.
2. The Ignition 1 signal parameter is between 11-18 volts.
3. The Current Gear parameter does not change.
4. The Intake Air Temperature (IAT) sensor parameter is less than 100°C (212°F).
5. The Engine Coolant Temperature (ECT) sensor parameter is between 5-150°C (41-230°F).
6. The Engine Speed parameter is between 1,000-1,800 RPM.
7. The Manifold Absolute Pressure (MAP) sensor parameter is between 11-50 kPa.
8. The Mass Air Flow (MAF) sensor parameter does not change more than 2 grams per second.
9. The Barometric Pressure (BARO) parameter is more than 74 kPa.
10. The Throttle Position (TP) sensor parameter is less than 1.19 percent.
11. The Vehicle Speed sensor parameter is more than 37 km/h (23 mph) during deceleration.
12. The vehicle will need to be driven more than 80 km/h (50 mph), and then allowed to decelerate. When the vehicle is decelerating, while meeting all of the criteria listed above, the ECM will enable the EGR flow test to run. As the EGR flow test is running, you will see the Desired EGR Position parameter and the EGR Position Sensor parameter on the scan tool momentarily change from 0 to a calibrated value above 0. Additionally, the EGR Flow Test Count parameter on the scan tool will increment when each EGR flow test is completed.
13. DTC P0401 runs once per trip typically, or 7 tests will be run per trip until 42 tests have been completed.

The MAP changes monitored by the ECM during the EGR flow tests indicate an insufficient amount of EGR flow for more than 2.8 seconds.

DTC P0401 is a Type A DTC.

Conditions for Clearing the DTC

DTC P0401 is a Type A DTC.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-poor)
4. «Wiring Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

1. If DTCs P0107, P0108, P0403, P0404, P0405, or P0406 are also set, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-trouble-code-dtc-list) for further diagnosis.
2. 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.

1. Verify the following conditions are not present: Incorrect EGR valve for engine application A vacuum leak between the EGR valve and the intake manifold Signs of external leakage usually indicated by carbon buildup around the mating surfaces of the components or an audible exhaust noise Restrictions in the passages or EGR valve caused by carbon deposits or casting flash MAP sensor for being shifted, stuck, skewed, and for correct vacuum supply IMPORTANT: Restrictions can cause excessive back pressure and low engine vacuum. Leaking, restricted, or modified exhaust system Mechanical failure in the engine such as worn piston rings, camshaft, or incorrect timing components installation-Refer to «Symptoms - Engine Mechanical»(/cadillac/dts/i-2005-2011/remont/mechanical/#engine-mechanical-46l-1-of-5) .
2. If all conditions test normal, replace the EGR valve. Refer to «Exhaust Gas Recirculation Valve Replacement»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2) .

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provide an overview of each diagnostic category.

Circuit Description

The engine control module (ECM) tests the exhaust gas recirculation (EGR) system during deceleration. The control module does this by momentarily commanding the EGR valve to open while monitoring the signal circuit of the manifold absolute pressure (MAP) sensor. When the EGR valve is opened, the control module will expect to see a predetermined increase in MAP. If the expected increase in MAP is not detected, the control module records the amount of MAP difference that was detected and adjusts a calibrated fail counter towards a calibrated fail threshold level. The number of EGR flow test counts required to exceed the fail threshold may vary according to the amount of detected EGR flow error.

The EGR valve position sensor is monitored by the ECM. The 5-volt reference circuit, the low reference circuit, and the EGR valve position signal circuit are used by the ECM to determine the EGR valve position. The ECM compares the EGR Position Sensor parameter with the desired EGR Position parameter when the valve is commanded open or closed.

The ECM controls the EGR valve with a solid state device called a driver. The driver supplies the EGR solenoid with 12 volts that is pulse width modulated (PWM) through the EGR solenoid high control circuit. A ground path is provided by the ECM through the EGR solenoid low control circuit.

When the ignition switch is turned ON, the ECM records the EGR Learned Minimum Position. The ECM compares the EGR Learned Minimum Position parameter to the EGR Position Sensor parameter.

P0403, P0404, P0405, P0406, P042E

1. The Ignition 1 Signal parameter is between 9-18 volts.
2. The engine is cranking or running.
3. The DTC P0401 intrusive test is not active.
4. These DTCs run continuously once the above conditions are met.

P0404

1. The EGR valve is commanded open.
2. DTC P0641 and P0651 are not set.

P0405

DTC P0641 and P0651 are not set.

P0406

1. DTC P0641 and P0651 are not set.
2. The EGR valve is not being commanded with a scan tool.

P042E

DTC P0641 and P0651 are not set.

P0403

The ECM detects an electrical malfunction in the EGR solenoid high control circuit or the EGR solenoid low control circuit for more than 10 seconds.

P0404

The difference between the EGR Position Sensor and the desired EGR Position is more than 15 percent for more than 34 seconds.

P0405

1. The EGR position sensor is less than 0.11 volts for more than 5 seconds.
2. The above condition is met for more than 20 seconds.

P0406

The EGR position sensor voltage is more than 4.77 volts for more than 18 seconds.

P042E

1. The EGR position sensor is 0.4 volt more than the EGR Learned Minimum Position when the Desired EGR Position is commanded to 0 percent for 24 seconds.
2. The EGR position sensor is more than 30 percent and is steady for 5 seconds after a test failure and before the next test will be run.
3. The above conditions are met 4 times.

DTC P0403, P0404, P0405, P0406, and P042E are Type B DTCs.

DTC P0403, P0404, P0405, P0406, and P042E are Type B DTCs.

Inspect for excessive deposits on the EGR valve pintle or seat. Remove the EGR valve and inspect for deposits that may interfere with the EGR valve pintle extending completely or cause the pintle to stick.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Exhaust Gas Recirculation (EGR) System Description

Electrical Information Reference

1. «Circuit Testing»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-poor)
4. «Wiring Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

1. With the ignition ON and the engine OFF, command the EGR from 0-90 percent. The EGR Position Sensor parameter should remain within 3 percent of the Desired EGR Position parameter through the entire range.
2. 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.

1. Ignition OFF, disconnect the EGR valve harness connector.
2. Ignition ON, connect a test lamp between B+ and the EGR low control circuit. The test lamp should illuminate. If the test lamp does not illuminate, test the EGR low control circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
3. Connect a test lamp between the EGR high control circuit and ground. Command the EGR valve from 0-90 percent and exit the EGR Solenoid Output Control. The test lamp should turn ON when commanded between 10 and 90 percent and turn OFF when exiting the EGR Solenoid Output Control. If the test lamp is ON after exiting the EGR Solenoid Output Control, test the EGR high control circuit for a short to voltage. If the circuit tests normal, replace the ECM. If the test lamp is always OFF while commanding the EGR valve from 0-90 percent, test the EGR high control circuit for an open, high resistance, or a short to ground. If the circuit tests normal, replace the ECM.
4. Ignition OFF, test for less than 1 ohm of resistance between the low reference circuit 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 ECM.
5. Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit and ground. If less than the specified range, test the 5-volt reference circuit for a short to ground, short to EGR Control circuits or an open/high resistance. If the circuit tests normal, replace the ECM. If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the ECM.
6. Verify the EGR Position parameter is less than 1 percent. If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the ECM.
7. Install a 3A fused jumper wire between the signal circuit and the 5-volt reference circuit. The EGR Position Sensor parameter should display more than 99 percent. 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 ECM.
8. If all circuits test normal, replace the EGR Valve.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Control Module References»(/cadillac/dts/i-2005-2011/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for control module replacement and programming
2. «Exhaust Gas Recirculation Valve Replacement»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2)

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provide an overview of each diagnostic category.

Typical Scan Tool Data

AIR Pressure Sensor

The secondary air injection (AIR) system aids in the reduction of hydrocarbon emissions during a cold start. The system forces fresh filtered air into the exhaust stream in order to accelerate the catalyst operation. The secondary AIR injection pump, provides filtered air on demand to the AIR check valve assembly. The AIR check valve assembly controls the flow of air from the AIR pump to the exhaust manifold. The AIR CNTRL relay supplies the current needed to operate the AIR solenoid that is integral to the check valve assembly. A pressure sensor, also integral to the check valve assembly, is used to monitor the air flow from the AIR pump. The control module supplies the internal pressure sensor with a 5-volt reference, an electrical ground, and a signal circuit. The signal circuit provides the control module with a voltage relative to internal AIR pressure changes.

The AIR diagnostic uses 3 phases to test the AIR system

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

During phase 1, both the AIR pump and the solenoid valve are activated. Normal secondary air function occurs. Expect system pressure is 8-10 kPa above BARO.

During phase 2, only the AIR pump is activated. The solenoid valve is closed. Pressure sensor performance and solenoid valve deactivation are tested. Expected system pressure is 10-20 kPa above BARO.

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

In all 3 phases, testing is accomplished by comparing the measured pressure against the expected pressure. The control module can detect faults in the AIR pump, AIR solenoid, pressure sensor, and the exhaust check valve. The pressure sensor can also detect leaks and restrictions in the secondary AIR system plumbing.

1. DTCs P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0128, P0201-P0208, P0300, P0301-P0308, P0351-P0358, P0412, P0418, P0420, P0606, P0641, P0651, P2430, P2431, P2432, P2433, P2440, 2444 are not set.
2. The system voltage is between 9-18 volts.
3. The intake air temperature (IAT) is greater than 5°C (41°F).
4. AIR system is commanded ON.
5. Conditions are stable for greater than 5 seconds.
6. DTC P0411 runs once per trip start up when the above conditions are met and AIR pump operation is requested.

1. The difference between the predicted system pressure and the actual system pressure is greater than 5 kPa. OR The difference between the predicted system pressure and the actual system pressure is less than -5 kPa.
2. DTC P0411 sets within 22 seconds when the above conditions are met.

DTC P0411 is a Type B DTC.

DTC P0411 is a Type B DTC.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-poor)
4. «Wiring Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

Description and Operation Reference

Secondary Air Injection System Description

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

1. If any other AIR DTCs are set, perform those diagnostics first.
2. Inspect the AIR solenoid outlet pipe for leaks.
3. Engine running, observe that the AIR Pressure Sensor parameter approximately equals BARO.
4. Engine running, enable the AIR pump relay with a scan tool and observe that the AIR Pressure Sensor parameter equals approximately 10-20 kPa above barometric pressure (BARO).
5. Engine running, enable the AIR system with a scan tool and observe that the AIR Pressure Sensor parameter equals approximately 8-10 kPa above BARO.
6. 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.

1. Ignition ON, observe that the AIR pump is not activated. If the AIR pump is activated, test the AIR pump voltage supply circuit for a short to voltage. If the circuit tests normal, test the AIR pump relay control circuit for a short to ground. If the circuits test normal, test the AIR pump relay. If the relay and circuits test normal, replace the ECM.
2. Ignition ON, enable the AIR pump with a scan tool and observe that the AIR pump is activated. If the AIR pump is not activated, test the AIR pump voltage supply terminal A and ground circuits terminal B for more than 2 ohms. If the circuits test normal, test both AIR pump relay voltage supply circuits for an open/high resistance or a short to ground. If the circuits test normal, test the AIR pump relay control circuit for and open/high resistance or a short to voltage. If the circuits test normal, test the AIR pump relay. If the relay and circuits test normal, test the AIR pump. If the relay, pump, and circuits test normal, replace the ECM.
3. Engine OFF, disconnect the harness connector at the AIR solenoid valve.
4. Connect a test lamp between the AIR solenoid voltage supply terminal 6 and ground circuit terminal 4.
5. Ignition ON, observe that the test lamp is not illuminated. If the test lamp is illuminated, test the AIR solenoid valve voltage supply circuit for a short to voltage. If the circuit tests normal, test the AIR solenoid valve relay control circuit for a short to ground. If the circuits test normal, test the AIR solenoid valve relay. If the relay and all circuits test normal, replace the ECM.
6. Ignition ON, enable the AIR solenoid with a scan tool and observe that the test lamp is illuminated. If the test lamp is not illuminated, test the AIR solenoid voltage supply circuit terminal 6 and both AIR solenoid relay voltage supply circuits for an open/high resistance or a short to ground. If the circuits test normal, test the AIR solenoid ground circuit terminal 4 for an open/high resistance. If the circuits test normal, test both AIR solenoid relay control circuits for and open/high resistance or a short to voltage. If the circuits test normal, test the AIR solenoid relay. If the relay and circuits test normal, replace the ECM.
7. Ignition OFF, connect all wiring harness connectors.
8. Engine RUNNING, enable the AIR system with a scan tool and observe the AIR Pressure Sensor parameter equals approximately 8-10 kPa above BARO. If not within the specified range, continue with this procedure.
9. Remove the AIR inlet hose from the AIR pump.
10. Engine RUNNING, enable the AIR system with a scan tool and observe the AIR Pressure Sensor parameter equals approximately 8-10 kPa above BARO. If within the specified range, the AIR pump inlet hoses/pipes are restricted. Remove the restriction or replace the hose/pipe. If not within the specified range, continue with this procedure.
11. Disconnect the hose from the AIR pump outlet.
12. Disconnect the hose quick-connect from the AIR solenoid valve inlet.
13. Install a length of standard 1-inch I.D., 25 4-mm, hose from the AIR pump outlet to the AIR solenoid valve inlet.
14. Engine RUNNING, enable the AIR system with a scan tool and observe the AIR Pressure Sensor parameter equals approximately 8-10 kPa above BARO. If within the specified range, the AIR pump outlet hoses/pipes are restricted or leaking. Remove the restriction or replace the hose/pipe. If less than the specified range, replace the AIR pump. If greater than the specified range, continue with this procedure.
15. Remove the AIR solenoid valve.
16. Leave the standard hose and harness connector connected.
17. Engine RUNNING, enable the AIR system with a scan tool and observe the AIR Pressure Sensor parameter increases to approximately 7 kPa above BARO. If greater than the specified range, replace the AIR solenoid valve. If within the specified range, test/inspect the exhaust manifold and exhaust system for restriction.

Relay Test

1. Test between the normally closed switch terminals, if any, for 0 ohms.
2. Test between the normally open switch terminals for infinite ohms.
3. Test between each switch terminal and either coil terminal for infinite ohms.
4. Connect the relay coil terminals to ground and fused power to energize the relay.
5. Test between each switch terminal and each coil terminal for 0 volts.
6. Test between the normally closed switch terminals, if any for infinite ohms.
7. Test between the normally open switch terminals for 0 ohms.

AIR Pump Dynamic Test

Connect the AIR pump to appropriately fused battery voltage and ground and observe for a pressurized airflow at the pump outlet.

1. If pressurized airflow is not observed, replace the pump.

AIR Solenoid Valve Dynamic Test

Apply appropriately fused battery voltage and ground to the solenoid terminals and verify that the valve opens and closes completely as voltage is applied to and removed from the solenoid terminals. Observe that the valve is not obstructed or leaking.

1. If the valve operates incorrectly, leaks, or is obstructed, remove the obstruction or replace the valve.

1. «Secondary Air Injection Pump Replacement»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2)
2. «Secondary Air Injection Check Valve Replacement»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2)
3. «Control Module References»(/cadillac/dts/i-2005-2011/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for engine control module (ECM) replacement, setup, and programming

1. Engine running, enable the AIR system with a scan tool and observe that the AIR Pressure Sensor parameter equals approximately 8-15 kPa above BARO.
2. Engine running, enable the AIR pump relay with a scan tool and observe that the AIR Pressure Sensor parameter equals approximately 10-20 kPa above BARO.

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provide an overview of each diagnostic category.

The secondary air injection (AIR) system aids in the reduction of hydrocarbon emissions during a cold start. The system forces fresh filtered air into the exhaust stream in order to accelerate the catalyst operation. The secondary AIR injection pump, provides filtered air on demand to the AIR check valve assembly. The AIR check valve assembly controls the flow of air from the AIR pump to the exhaust manifold. The AIR CNTRL relay supplies the current needed to operate the AIR solenoid that is integral to the check valve assembly. A pressure sensor, also integral to the check valve assembly, is used to monitor the air flow from the AIR pump. The control module supplies the internal pressure sensor with a 5-volt reference, an electrical ground, and a signal circuit. The signal circuit provides the control module with a voltage relative to internal AIR pressure changes.

The AIR diagnostic uses 3 phases to test the AIR system

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

In all 3 phases, testing is accomplished by comparing the measured pressure against the expected pressure. The control module can detect faults in the AIR pump, AIR solenoid, pressure sensor, and the exhaust check valve. The pressure sensor can also detect leaks and restrictions in the secondary AIR system plumbing.

1. The system voltage is between 9-18 volts.
2. This DTC runs on a 250 ms loop.
3. DTC P0412 and DTC P0418 run continuously when the above conditions are met.

1. The actual and expected states of the AIR solenoid and AIR pump relay control circuits do not match.
2. The condition exists for at least 5 seconds.

DTCs P0412 and P0418 are Type B DTCs.

DTCs P0412 and P0418 are Type B DTCs.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-poor)
4. «Wiring Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

Description and Operation Reference

Secondary Air Injection System Description

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

1. Ignition ON, command the affected relay ON and OFF with a scan tool. Feel or listen to verify that the affected relay turns ON and OFF with each command.
2. Engine running, observe the DTC information with a scan tool. DTCs P0412 or P0418 should not set.
3. 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.

1. Ignition OFF, disconnect the affected relay.
2. Ignition ON, connect a test lamp between the positive terminal at the battery and the relay control circuit terminal.
3. Command the 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 relay control circuit for a short to ground. If the circuit tests normal, replace the ECM. If the test lamp is always OFF, test the relay control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the ECM.
4. Connect an appropriately fused jumper wire between the positive voltage terminal at the battery and the load voltage supply circuit terminal and verify load activation. If the load does not activate, test the load voltage supply circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the load.
5. Ignition ON, connect an appropriately fused jumper wire between the relay switch voltage supply circuit terminal and the load voltage supply circuit terminal and verify load activation. If the load does not activate, test the relay switch voltage supply circuit for a short to ground or an open/high resistance. If the circuit tests normal and its fuse is open, test all components connected to the fuse and replace as necessary.
6. Ignition ON, verify that a test lamp illuminates between the relay coil voltage supply circuit terminal and ground. If the test lamp does not illuminate, test the relay coil voltage supply circuit for a short to ground or an open/high resistance.
7. If all circuits and the ECM test normal, test or replace the affected relay.

Relay Test

1. Test between the normally-closed switch terminals, if any, for 0 ohms.
2. Test between the normally-open switch terminals for infinite ohms.
3. Test between each switch terminal and either coil terminal for infinite ohms.
4. Connect the relay coil terminals to ground and fused power to energize the relay.
5. Test between the normally-closed switch terminals, if any, for infinite ohms.
6. Test between the normally-open switch terminals for 0 ohms.
7. Test between each switch terminal and either coil terminal for 0 volts.

Ignition ON, command the relay ON and OFF with a scan tool. Feel or listen to verify that the relay turns ON and OFF with each command.

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provide an overview of each diagnostic category.

A 3-way catalytic (TWC) converter controls emissions of hydrocarbons (HC), carbon monoxide (CO), and oxides of nitrogen (NOx). The TWC also stores oxygen. When the listed idle conditions follow the listed driving conditions the Catalyst System Efficiency test will run. The engine control module (ECM) monitors this oxygen storage capacity by comparing the pre and post-catalyst oxygen sensor signals while adding and subtracting fuel during specific idle conditions.

The ECM compares the pre- and post-catalyst oxygen sensor signals to determine if the oxygen storage capacity of the catalyst is degraded.

1. Driving Conditions DTCs P0030, P0036, P0053, P0054, P0059, P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0128, P0131, P0132, P0133, P0134, P0135, P0137, P0138, P0140, P0141, P0151-P0155, P0171, P0172, P0174, P0175, P0201-P0208, P0220, P0222, P0223, P0315, P0300, P0301-P0308, P0335, P0336, P0340, P0341, P0351-P0358, P0401, P0403, P0404, P0405, P0406, P0411, P0412, P0418, P0442, P0443, P0446, P0449, P0451, P0452, P0453, P0454, P0455, P0496, P0506, P0507, P060D, P1101, P1133, P1153, P1174, P1175, P1258, P1400, P1404, P1516, P2101, P2119, P2120, P2122, P2123, P2125, P2127, P2128, P2135, P2138, P2176, P2430, P2431, P2432, P2433, P2440, P2444, P2A00, P2A01, P2A03, or U0107 are not set. The engine has been running for greater than 6 minutes. The vehicle is in Closed Loop. The vehicle has Fuel Trim enabled. The engine coolant temperature (ECT) is between 70-125°C (158-257°F). The barometric pressure (BARO) is greater than 70 kPa. The intake air temperature (IAT) is greater than -20°C (-4°F). The throttle position (TP) is less than 2 percent. The calculated TWC temperature (Calc. TWC Temp.) is between 385-640°C (725-1,184°F). The battery voltage is greater than 10.7 volts.
2. Idle Conditions The vehicle speed is less than 3.2 km/h (2 mph). The engine speed has been greater than 1,200 RPM for 25 seconds. The automatic transmission is in Reverse, Drive, or Low. The TP is less than 2 percent. The short term fuel trim (FT) is between -10 and +10 percent. The engine speed is less than 1,000 RPM. The engine idle is stable. This diagnostic attempts one test during each valid idle period when the above conditions have been met. These diagnostic attempts up to 6 tests during each drive cycle.

1. The ECM has determined that the catalyst efficiency has degraded below a calibrated threshold.
2. This diagnostic may conclude in one test attempt. However, this diagnostic may require as many as 18 test attempts, which would require at least 3 drive cycles. Each test attempt may conclude within approximately 1 minute.

DTC P0420 is a Type A DTC.

DTC P0420 is a Type A DTC.

Electrical Information Reference

1. «Circuit Testing»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-poor)
4. «Wiring Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Note. Refer to Heated Oxygen Sensor Resistance Learn Reset Notice .

Note. Refer to Three-Way Catalytic Converter Damage Notice .

1. Verify that no other DTCs are set. If any DTCs are set, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-trouble-code-dtc-list) .
2. 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 A catalyst test may abort if the vehicle falls outside the conditions for running the DTC. A catalyst test may be temporarily degraded if a fuel with high sulfur content has been used. Drive the vehicle at highway speeds for 10 minutes and retest the converter.
3. Operate the vehicle within the Conditions for Running the DTC. If the DTC fails this key cycle, continue with this procedure.
4. Inspect the catalytic converter for the following conditions: 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.
5. Inspect the exhaust system for the following conditions: Leaks Physical damage Loose or missing hardware Properly torqued HO2S Restrictions If a condition is found, repair the exhaust system.
6. Inspect the post catalyst HO2S for the following conditions: A grounded wiring harness Damage If a condition is found, replace the post catalyst HO2S. If no physical condition is detected, replace the catalytic converter.
7. 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.

1. «Heated Oxygen Sensor Replacement - Bank 1 Sensor 2»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2)
2. «Exhaust System Replacement»(/cadillac/dts/i-2005-2011/remont/exhaust/#engine-exhaust-system)
3. «Exhaust System Insulator, Hanger, Bracket Replacement»(/cadillac/dts/i-2005-2011/remont/exhaust/#engine-exhaust-system)
4. «Restricted Exhaust»(/cadillac/dts/i-2005-2011/remont/exhaust/#engine-exhaust-system)

1. Clear all DTCs.
2. Allow the engine coolant temperature to reach 70°C (156°F). Place the gear selector in Park, Neutral for manual. Set the parking brake.
3. Press and hold the service brake.
4. Run the engine for 6 minutes at 2,500 RPM.
5. Allow engine speed to return to idle speed, then place gear selector into Drive, or apply clutch pedal for manual.
6. After 2 minutes, verify that DTC P0420 has passed or failed this ignition cycle. If not passed or failed this ignition cycle, the test aborted resulting in an inconclusive test result. The above test may need to be repeated up to 5 more times during this drive cycle. The first test should be run after the initial warm up period of 6 minutes. Between subsequent tests, maintain 2,500 RPM for 2 minutes.
7. If 6 tests have been attempted and the DTC has not run or passed during this key cycle, turn the key to OFF for 30 seconds, then run the procedure a second time.

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

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 a vehicle 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 corresponding pressure changes in the fuel tank vapor space. This change is monitored by the control module using the fuel tank pressure sensor input. The control module then makes a judgment on the integrity of the system. With a 0.51 mm (0.02 in) leak in the system, the amount of pressure change observed is significantly less than that of a sealed system.

1. Before the powertrain control module (PCM) can report DTC P0442 failed, DTCs P0446, P0455, and P0496 must run and pass.
2. DTCs P0112, P0113, P0116, P0117, P0118, P0120, P0128, P0443, P0446, P0449, P0452, P0453, P0463, P1106, P1107, P1111, P1112, P1114, P1115, P1516, P2101, P2108, P2120, P2125, P2129, P2138, P2610 are not set.
3. The diagnostic runs once after a cold start drive cycle.
4. The start-up intake air temperature (IAT) is less than 30°C (86°F).
5. The start-up engine coolant temperature (ECT) is less than 30°C (86°F).
6. The start-up IAT and ECT are within 8°C (15°F).
7. The barometric pressure (BARO) is more than 74 kPa.
8. The ambient air temperature is between 2-32°C (36-90°F).
9. The engine run time minimum is 10 minutes.
10. The vehicle has traveled more than 8 kilometers (5 miles) this trip.
11. The ECT is more than 70°C (158°F).
12. The fuel level is between 15-85 percent.
13. The ignition is OFF.
14. A refueling event is not detected.
15. DTC P0442 runs once per drive cycle when the above conditions are met.
16. One test occurs at ignition OFF after a drive cycle, and may require up to 45 minutes to complete. No more than 2 tests per day are allowed.

1. The control module detects a pressure change that is less than a calibrated amount.
2. Several tests must be completed to report a Fail with up to 17 hours between tests.

DTC P0442 is a Type A DTC.

DTC P0442 is a Type A DTC.

1. To help locate intermittent leaks, use the J 41413-200 to introduce smoke into the EVAP system. See «Special Tools»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2) . Move all EVAP components while observing smoke with the J 41413-SPT . See «Special Tools»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2) .
2. To improve the visibility of the smoke exiting the EVAP system, observe the suspected leak area from different angles with the J 41413-SPT . See «Special Tools»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2) .
3. A condition may exist where a leak in the EVAP system only exists under a vacuum condition. By using the scan tool Purge/Seal function to create a vacuum, seal the system and observe the FTP parameter for vacuum decay, this type of leak may be detected.

Schematic Reference

Evaporative Emissions Hose Routing Diagram

Electrical Information Reference

1. «Circuit Testing»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-poor)
4. «Wiring Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Special Tools

1. J 41413-200 Evaporative Emission System Tester (EEST). See «Special Tools»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2) .
2. GE-41415-50 Fuel Tank Cap Adapter. See «Special Tools»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2) .
3. J 41413-SPT High Intensity White Light. See «Special Tools»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2) .
4. CH-48096 EVAP Service Access Port Tool. See «Special Tools»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2) .

1. Connect the J 41413-200 to the vehicle at the EVAP service port. See «Special Tools»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2) . For vehicles without a service port, disconnect the purge tube at the quick connector on the EVAP canister side of the purge solenoid valve and install the CH-48096 . See «Special Tools»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2) .
2. Seal the EVAP system and use the flow meter on the J 41413-200 , calibrated to 0. See «Special Tools»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2) .51 mm (0.020 in) to determine that there is no leak in the EVAP system. If a leak is detected use the J 41413-200 to apply smoke to the EVAP system at the service port or the purge tube until the leak is located. See «Special Tools»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2) .

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provide an overview of each diagnostic category.

An ignition voltage is supplied directly to the evaporative emission (EVAP) canister purge solenoid valve. The control module controls the EVAP canister purge solenoid valve ON by grounding the control circuit by means of an internal switch called a driver. The control module monitors the status of the driver. The EVAP canister purge solenoid valve is pulse width modulated (PWM). The scan tool displays the amount of ON time as a percentage.

Battery voltage is supplied to the EVAP canister vent solenoid valve. The control module grounds the EVAP canister vent solenoid valve control circuit to close the valve by means of an internal switch called a driver. The control module monitors the status of the driver. The scan tool displays the commanded state of the EVAP canister vent solenoid valve as ON or OFF.

1. The ignition is ON.
2. The system voltage is between 9-18 volts.
3. DTCs P0443 and P0449 run continuously when the above conditions are met.

The control module detects that the commanded state of the driver and the actual state of the control circuit do not match, for a minimum of 12 seconds.

DTCs P0443 and P0449 are Type B DTCs.

DTCs P0443 and P0449 are Type B DTCs.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Troubleshooting with a Test Lamp»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-poor)
4. «Wiring Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

P0443

1. With the ignition ON, engine OFF, you should hear a clicking sound when the EVAP canister purge solenoid valve is commanded to 50 percent with a scan tool. The clicking sound should stop when the EVAP canister purge solenoid valve is commanded to 0 percent. The rate at which the valve cycles should increase when the commanded state is increased, and decrease when the commanded state is decreased.
2. 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 Records data.

P0449

1. With the ignition ON and the engine OFF, command the EVAP vent solenoid ON and OFF with a scan tool.
2. Listen for a click when the valve operates. Verify that both the ON, and the OFF states are commanded.
3. 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 Records data.

1. Ignition OFF, disconnect the harness connector at the EVAP canister vent solenoid valve.
2. Ignition ON, verify that a test lamp illuminates between the voltage supply circuit terminal A and ground. If a 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 canister purge solenoid.
3. Connect a test lamp between the voltage supply circuit terminal A and the control circuit terminal B.
4. Energize the solenoid with a scan tool. Command the EVAP canister purge solenoid valve to 50 percent with a scan tool, or the EVAP canister vent solenoid valve ON and OFF. 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 control module. 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 control module.
5. If all circuits test normal, replace the appropriate solenoid valve.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Evaporative Emission Canister Purge Solenoid Valve Replacement»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2)
2. «Evaporative Emission Canister Vent Solenoid Valve Replacement»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2)
3. «Control Module References»(/cadillac/dts/i-2005-2011/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for engine control module (ECM) replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__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 canister purge solenoid valve Open while the EVAP canister vent solenoid valve remains Open. The test will fail if the vacuum level increases above a calibrated level.

1. Before the engine control module (ECM) can report DTC P0446 failed, DTCs P0442 and P0496 must run and pass.
2. DTCs P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0125, P0128, P0443, P0449, P0451, P0453, P0454, P1106, P1107, P1111, P1112, P1114, P1115, P1125, P1516, P2101, P2108, P2119, P2120, P2125, P2138 are not set.
3. The ignition voltage is between 10-18 volts.
4. The barometric pressure (BARO) is more than 74 kPa.
5. The fuel level is between 15-85 percent.
6. The start-up engine coolant temperature (ECT) is less than 30°C (86°F).
7. The start-up intake air temperature (IAT) is less than 30°C (86°F).
8. The start-up ECT and IAT are within 9°C (16°F) of each other.
9. DTC P0446 runs once per trip when the above conditions have been met.

1. The fuel tank pressure (FTP) sensor is more than 8 inches H2O vacuum for 2 seconds during the 13 minute test. OR The FTP is less than -2.5 inches H2O or more than +5 inches H2O for 3 seconds after a cold start ignition ON.
2. The fuel tank vacuum is greater than a calibrated amount for a calibrated period of time.

DTC P0446 is a Type B DTC.

DTC P0446 is a Type B DTC.

1. An intermittent condition could be caused by a damaged EVAP vent housing, a temporary blockage at the EVAP canister vent solenoid valve inlet, or a pinched vent hose. A blockage in the vent system will also cause a poor fuel fill problem.
2. An EVAP canister filter that is restricted can cause this DTC to set. Refer to «Evaporative Emission Canister Replacement»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2) .

Schematic Reference

1. «Evaporative Emissions Hose Routing Diagram»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2)
2. «Engine Controls Schematics»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2)

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-poor)
3. «Wiring Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Special Tools

1. GE-41415-50 Fuel Tank Cap Adapter. See «Special Tools»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2) .
2. J 41413-200 Evaporative Emissions System Tester (EEST). See «Special Tools»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2) .

1. Ignition ON and fuel cap removed, verify that the FTP sensor parameter is between 1.3-1.7 volts. If not within the specified range, go to the FTP sensor section in Circuit/System Testing.
2. Install the fuel cap.
3. 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 12 inches H2O. If the fuel tank vacuum is greater than the specified range, go to the restriction section in Circuit/System Testing.
4. 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 Records data.

Restriction

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 12 inches H2O.

1. 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 percent and the vent valve is open.

FTP Sensor

1. Ignition ON and fuel cap removed, verify that the FTP sensor parameter is between 1.3-1.7 volts. If the FTP sensor parameter is not within the specified range, test the FTP low reference circuit for an open or high resistance. If the circuit tests normal, replace the FTP sensor.
2. With the GE-41415-50 , connect the J 41413-200 to the fuel filler neck. See «Special Tools»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2) .
3. Start the engine.
4. Allow the engine to idle.
5. Use the Purge/Seal function to seal the system with a scan tool.
6. Command the EVAP canister purge solenoid valve to 20 percent.
7. Observe the vacuum/pressure gage on the J 41413-200 and the FTP parameter on the scan tool. See «Special Tools»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2) .
8. Verify that the vacuum increases to the abort limit on the scan tool or more than 3.2 volts, and the value is closely similar between the scan tool and the vacuum/pressure gage on the J 41413-200 . See «Special Tools»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2) . If the values are not similar or the voltage is not within the specified range, replace the FTP sensor.

1. «Fuel Tank Pressure Sensor Replacement»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2)
2. «Control Module References»(/cadillac/dts/i-2005-2011/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for engine control module (ECM) replacement, setup, and programming
3. «Evaporative Emission System Cleaning»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2)

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 12 inches H2O.

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

FTP Sensor Voltage

The fuel tank pressure (FTP) sensor measures air pressure or vacuum in the evaporative emission (EVAP) system. The control module supplies a 5-volt reference and a low reference circuit to the FTP sensor. The FTP sensor signal voltage varies depending on EVAP system pressure or vacuum. The controller 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

1. DTC P0451 runs only when the engine-off natural vacuum small leak test, P0442, executes.
2. 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 minutes.

P0452 and P0453

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

P0454

1. DTC P0454 runs only when the engine-off natural vacuum small leak test, P0442, executes.
2. This test can run once per engine-off period. The length of the test can be up to 10 minutes.
3. 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 volt for more than 5 seconds.

P0453

The FTP sensor voltage is more than 4.9 volts for more than 5 seconds.

P0454

If, during the engine-off natural vacuum small leak test, P0442, the engine control module (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 inch H2O in the span of 1 second.

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

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

P0451 and P0454

1. 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.
2. Ensure that the reference port on the FTP sensor is unobstructed.
3. 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 percent, 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 J 41413-200 while taking a snapshot. See «Special Tools»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2) .

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-poor)
4. «Wiring Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Special Tools

J 41413-200 Evaporative Emission System Tester (EEST). See Special Tools .

1. Ignition ON, observe the scan tool fuel tank pressure (FTP) sensor parameter. The reading should be between 1.3-1.7 volts with the fuel cap removed, and change with fuel tank pressure.
2. Engine running, observe the DTC information with a scan tool. DTCs P0451, P0452, P0453 or P0454 should not set.
3. 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 Records data.

1. Ignition OFF, disconnect the harness connector at the FTP sensor.
2. Ignition OFF, test for less than 5 ohms between the low reference circuit terminal A 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 control module.
3. Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit terminal C and ground. If less than the specified range, test the 5-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the control module. If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the control module.
4. Verify the scan tool FTP sensor parameter is less than 0.1 volts. If greater than the specified range, test the signal circuit terminal B for a short to voltage. If the circuit tests normal, replace the control module.
5. Install a 3A fused jumper wire between the signal circuit terminal B and the 5-volt reference circuit terminal C. Verify the scan tool FTP sensor parameter is greater than 4.7 volts. 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 control module.
6. If all circuits test normal, test or replace the FTP sensor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Fuel Tank Pressure Sensor Replacement»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2)
2. «Control Module References»(/cadillac/dts/i-2005-2011/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for engine control module (ECM) replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The control module tests the evaporative emission (EVAP) system for a large leak. The control module monitors the fuel tank pressure (FTP) sensor signal to determine the EVAP system vacuum level. When the conditions for running are met, the control module commands the EVAP canister purge solenoid valve OPEN and the EVAP vent solenoid valve CLOSED. This allows engine vacuum to enter the EVAP system. At a calibrated time, or vacuum level, the control module commands the EVAP canister purge solenoid valve closed, sealing the system, and monitors the FTP sensor input in order to determine the EVAP system vacuum level. The following table illustrates the relationship between the ON and OFF states, and the OPEN or CLOSED states of the EVAP canister purge and vent solenoid valves.

1. DTCs P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0125, P0442, P0443, P0446, P0449, P0452, P0453, P1111, P1112, P1114, P1115, P1516, P2101, P2119, P2120, P2125, P2135, P2138 are not set.
2. The engine is running.
3. The ignition voltage is between 10-18 volts.
4. The barometric pressure (BARO) is more than 74 kPa.
5. The fuel level is between 15-85 percent.
6. The start-up engine coolant temperature (ECT) is less than 30°C (86°F).
7. The start-up intake air temperature (IAT) is less than 30°C (86°F).
8. The start-up ECT and IAT are within 8°C (14°F) of each other.
9. DTC P0455 runs once per cold start within 16 minutes of start-up.

The EVAP system is not able to achieve or maintain vacuum for up to 4 times during the diagnostic test.

DTC P0455 is a Type B DTC.

DTC P0455 is a Type B DTC.

1. A loose, missing, incorrect, or damaged fuel fill cap may cause this DTC to set.
2. To help locate intermittent leaks, use the J 41413-200 to introduce smoke into the EVAP system. See «Special Tools»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2) . Move all EVAP components while observing smoke with the J 41413-SPT . See «Special Tools»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2) . Introducing smoke in 15-seconds intervals will allow less pressure into the EVAP system. When the system is less pressurized, the smoke will sometimes escape in a more condensed manner.
3. To improve the visibility of the smoke exiting the EVAP system, observe the suspected leak area from different angles with the J 41413-SPT . See «Special Tools»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2) .

Schematic Reference

1. «Evaporative Emissions Hose Routing Diagram»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2)
2. «Engine Controls Schematics»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2)

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-poor)
3. «Wiring Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Special Tools

1. J 41413-200 Evaporative Emission System Tester (EEST). See «Special Tools»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2) .
2. GE-41415-50 Fuel Tank Cap Adapter. See «Special Tools»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2) .
3. J 41413-SPT High Intensity White Light. See «Special Tools»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2) .
4. J 41413-300 EVAP Cap and Plug Kit
5. J 41413-311 EVAP Plug

1. Connect the J 41413-200 to the vehicle EVAP service port. See «Special Tools»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2) . For vehicles without a service port, disconnect the purge tube at the quick connector on the EVAP canister side of the purge solenoid valve and install the CH-48096 . See «Special Tools»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2) .
2. Seal the EVAP system and use the flow meter on the J 41413-200 calibrated to 0. See «Special Tools»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2) .51 mm (0.02 in) to determine that there is no leak in the EVAP system. If a leak is detected, use the J 41413-200 to apply smoke to the EVAP system at the service port until the leak is located. See «Special Tools»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2) .
3. To test for a restriction, connect the J 41413-200 nitrogen/smoke hose to the J 41413-311 brass cone adapter. See «Special Tools»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2) . Disconnect the hose at the fuel cap end of the GE-41415-50 . See «Special Tools»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2) . Connect the J 41413-311 to the disconnected hose on the GE-41415-50 . See «Special Tools»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2) . Install the GE-41415-50 filler neck end only to the vehicle. See «Special Tools»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2) .
4. Allow the engine to idle.
5. Use the Purge/Seal function to seal the system with a scan tool.
6. Command the EVAP canister purge solenoid valve to 30 percent.
7. The vacuum/pressure gage on the J 41413-200 and the FTP parameter on the scan tool should both show vacuum. See «Special Tools»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2) . If the vacuum/pressure gage shows vacuum, but the FTP parameter does not show vacuum, replace the FTP sensor. If neither the FTP parameter nor the vacuum/pressure gage shows vacuum, repair the restriction in the purge path. Refer to «Evaporative Emissions Hose Routing Diagram»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2) .
8. Verify that the vacuum increases to the abort limit on the scan tool or more than 3.2 volts, and the value is closely similar between the scan tool and the vacuum/pressure gage on the J 41413-200 . See «Special Tools»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2) . If the values are not similar or the voltage did not reach 3.2 volts, replace the FTP sensor.

1. «Fuel Tank Pressure Sensor Replacement»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2)
2. «Control Module References»(/cadillac/dts/i-2005-2011/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for engine control module (ECM) replacement, setup, and programming
3. «Evaporative Emission System Cleaning»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2)

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__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 canister purge solenoid valve OFF and the EVAP canister vent solenoid valve ON. The control module 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 canister purge and vent solenoid valves.

1. DTCs P0107, P0108, P0112, P0113, P0117, P0118, P0125, P0128, P0442, P0443, P0446, P0449, P0452, P0453, P1516 are not set.
2. The ignition voltage is between 10-18 volts.
3. The barometric pressure (BARO) is more than 74 kPa.
4. The fuel level is between 15-85 percent.
5. The engine coolant temperature (ECT) is less than 30°C (86°F).
6. The start-up IAT is less than 30°C (86°F).
7. The intake air temperature (IAT) is between 4-30°C (39-86°F).
8. The start-up ECT and IAT are within 8°C (14°F) of each other.
9. The FTP sensor is less than -2.5 inches H2O at ignition ON.
10. DTC P0496 runs once per cold start for 96 seconds.

1. The control module detects vacuum during a non-purge condition.
2. The FTP sensor is more than -10 inches H2O for 60 seconds.

DTC P0496 is a Type B code.

DTC P0496 is a Type B code.

Schematic Reference

1. «Engine Controls Schematics»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2)
2. «Evaporative Emissions Hose Routing Diagram»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2)

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Troubleshooting with a Test Lamp»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-poor)
4. «Wiring Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

1. Start the engine.
2. Seal the EVAP system using the Purge/Seal function with a scan tool.
3. Observe the FTP sensor with a scan tool. The Fuel Tank Pressure Sensor parameter should be less than 1.7 volts after 90 seconds. If the Fuel Tank Pressure Sensor parameter is greater than specified range, replace the EVAP canister purge solenoid valve.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Evaporative Emission Canister Purge Solenoid Valve Replacement

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provide an overview of each diagnostic category.

The throttle actuator control (TAC) motor is controlled by the engine control module (ECM). The DC motor located in the throttle body drives the throttle blade. In order to decrease idle speed, along with spark and fuel delivery changes the ECM commands the throttle closed reducing air flow into the engine and the idle speed decreases. In order to increase idle speed, the ECM commands the throttle plate open allowing more air to pass the throttle plate. If the difference between the desired and actual engine speed is greater than a specified range, these DTCs will set.

1. DTCs P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0122, P0123, P0128, P0171, P0172, P0174, P0175, P0201-P0208, P0220, P0222, P0223, P0300, P0301-P0308, P0351-P0358, P0336, P0401, P0403, P0404, P0405, P0496, P0440, P0442, P0443, P0446, P0452, P0453, P0496, P0502, P0503, P0601, P0604, P0606, P0641, P0651, P0722, P0723, P1514, P1516, P1680, P2101, P2120, P2122, P2123, P2127, P2128, P2135, P2138, P2176 are not set.
2. The engine is operating for at least 60 seconds.
3. The engine coolant temperature (ECT) is greater than -15°C (+5°F).
4. The intake air temperature (IAT) is greater than -18°C (0°F).
5. The barometric pressure (BARO) is greater than 65 kPa.
6. The system voltage is between 10.5-18 volts.
7. The engine is at a stable idle for greater than 2 seconds.
8. DTC P0506 and P0507 run continuously when the above conditions are met.

P0506

1. The actual idle speed is approximately 90 RPM lower than the desired idle speed continuously
2. The above condition is present for 3 tests consisting of 8 seconds for each test.

P0507

1. The actual idle speed is approximately 90 RPM greater than the desired idle speed.
2. The above condition is present for 3 tests consisting of 8 seconds for each test..

DTCs P0506 and P0507 are Type B DTCs.

DTCs P0506 and P0507 are Type B DTCs.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Throttle Actuator Control (TAC) System Description

Electrical Information Reference

1. «Circuit Testing»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-poor)
4. «Wiring Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

1. Verify that no other DTCs set. If any other DTCs are set, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-trouble-code-dtc-list) .
2. Compare the desired engine idle speed to the actual engine idle speed with a scan tool. Actual engine idle speed should be no greater than or less than 100 RPM of desired.
3. Command the engine speed up and down with a scan tool. Increase the engine speed in 25 RPM increments while comparing the desired engine speed to the actual engine speed, the actual engine speed should stay within 25 RPM of the desired engine speed.
4. Engine running, observe the DTC information with a scan tool. DTCs P0506 or P0507 should not set.
5. 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.

Circuit System Testing

1. Inspect for any condition that can reduce idle speed by increasing engine load. Incorrect torque converter clutch (TCC) operation Accessories that require additional torque to operate Excessive deposits in the throttle body-Refer to «Throttle Body Inspection and Cleaning»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2__throttle-body-inspection-cleaning) . Restricted exhaust-Refer to «Restricted Exhaust»(/cadillac/dts/i-2005-2011/remont/exhaust/#engine-exhaust-system) . Mechanical conditions that limit engine speed
2. Inspect for any condition that can increase idle speed. Vacuum leaks Unmetered air entering the engine, after the mass air flow A faulty positive crankcase ventilation (PCV) valve

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

This diagnostic applies to internal microprocessor integrity conditions within the engine control module (ECM) and the throttle actuator control (TAC) system. This diagnostic also addresses if the ECM is not programmed.

The ECM monitors its ability to read and write to the memory. It also monitors a timing function. The ECM and the TAC processors are used to monitor the TAC system data. Both processors monitor the other processors data to verify that the indicated APP calculation is correct. The ECM performs an intrusive test in order to confirm that the APP signals are not shorted together. The ECM accomplishes this by pulling the APP sensor 2 low momentarily and looking for sensor 1 to also be pulled low.

P0601, P0603

1. The ignition switch is in Run or Crank.
2. The system voltage is more than 5 volts.

P0602

1. The ignition switch is in Run or Crank.
2. The controller is identified as a service replacement ECM.

P0604, P062F

The ignition switch is in Run or Crank.

P0606

1. The ignition switch is in Run or Crank.
2. During test function after key off before the control module powers down.

P0607

1. The ignition switch is in Unlock, Accessory, Run or Crank.
2. The system voltage is more than 5.23 volts.
3. DTCs P0601, P0602, P0603, P0604, P0606, P0607, P062F, P0641, P0651, P2610 are not set

P060D

1. The ignition switch is in Run or Crank.
2. The system voltage is more than 5 volts.

P2610

1. The ignition switch is in the OFF position for at least 1.6 seconds.
2. A low battery voltage or a battery disconnect condition has not taken place. Ignition OFF timer from the previous ignition cycle is stored.

P0601

The ECM checksum value is incorrect for at least one sample. Each sample is 50 milliseconds. The ECM detects that the check sum value is incorrect for 0.05 second. This diagnostic runs continuous.

P0602

The ECM has not been programmed with Key On and Engine Off for one sample. Each sample is 100 milliseconds. The ECM has not been programmed at Key On and Engine Off for 0.1 second. This diagnostic runs continuous.

P0603

The ECM check sum value at the last power down does not match the ECM check sum value during the current power up for one sample. Each sample is 10 milliseconds. The ECM detects that the check sum value at the last power down does not match the ECM check sum value during the current power up is incorrect for 0.01 second. This diagnostic runs once per ignition cycle at power up.

P0604

The ECM is unable to correctly write and read to and from random access memory (RAM) during the following conditions

1. Key up initialization for one count. Each count is a read and write sample. Each sample is 100 milliseconds. This portion runs once per ignition cycle.
2. Counter increments by 10 for each sample that does not correctly read and write to the RAM, and decrements by one for each correct sample. No more than 20 counts which do not read and or write correctly. Each read and write sample is 100 milliseconds. This portion runs continuously.
3. Counter increments by 10 for each sample that does not correctly read and write to the Desired Throttle Position RAM and decrements by one for each correct sample. No more than 20 counts which do not read and or write correctly. Each read and write sample is 12.5 milliseconds. This portion runs continuously.

P0606

The ECM detects that the TAC system has a process sequence error, clock error, and 2 motor processor errors, or ETC Internal Processor is not operating correctly. Each test runs in 12.5, 25, 50, 100 and 250 milliseconds. This DTC runs continuously.

P0607

The state of health discrete line between the ETC internal processor and the ECM is not toggling for more than 0.5 seconds. This DTC runs continuously.

P060D

The difference between the main processor (ECM) indicated accelerator pedal position and the MHC processor indicated accelerator pedal position is more than 2.5 percent.

P062F

The ECM did not complete the last electrically erasable programmable read only memory (EEPROM) write event during the last ECM power down. This diagnostic runs once per ignition cycle at power up.

P2610

This diagnostic has 2 tests that may set this DTC

Phase 1

1. The ECM detects the ignition off timer is less than 1 second at any time. OR
2. The ECM detects the ignition off timer is 15 seconds or more if the actual elapsed time is less than 15 seconds.
3. This diagnostic runs continuous.

Phase 2

1. The last ignition off time event increments more than 1.375 seconds or less than 0.8 second for each second.
2. This diagnostic runs continuous.

Actions Taken When the DTC Sets

P0601, P0602, P0603, P0604, P0606, P0607, P060D, or P062F

1. The control module illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame/Failure Records.

P2610

1. The control module illuminates the MIL on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.
3. If the diagnostic reports a failure, the control module uses a cold start model based on the engine coolant temperature and intake air temperature at engine start-up. Using the cold start model ensures that the control module is able to determine how much time has elapsed between ignition cycles.

1. The control module turns OFF the MIL after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

1. Observe the DTCs with the scan tool. If DTC P0602 is set, attempt to program the ECM before replacing the ECM. Refer to «Service Programming System (SPS)»(/cadillac/dts/i-2005-2011/remont/communication-devices/#programming-and-setup-all-systems__service-programming-system-sps) . If DTC P0602 resets, replace the ECM.
2. Test the voltage and ground circuits to the control module for the following: A short An open High resistance

1. If all circuits test OK, replace the ECM.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for ECM replacement, programming and setup

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The control module has 2 internal 5-volt reference busses called 5-volt reference 1 and 5-volt reference 2. Each reference bus provides 5-volt reference circuits for more than one sensor. Therefore, a fault condition on one 5-volt reference circuit will affect the other 5-volt reference circuits connected to that reference bus. The control module monitors the voltage on the 5-volt reference busses.

The 5-volt reference 1 bus provides 5 volts to the following sensors

1. The air conditioning (A/C) refrigerant pressure sensor
2. The manifold absolute pressure (MAP) sensor
3. The fuel tank pressure (FTP) sensor
4. The accelerator pedal position (APP) sensor 2
5. The exhaust gas recirculation (EGR) position sensor
6. The camshaft position (CMP) sensor

The 5-volt reference 2 bus provides 5 volts to the following sensors

1. The APP sensor 1
2. The throttle position (TP) sensor 1 and 2
3. The secondary air injection (AIR) Solenoid
4. The crankshaft position (CKP) sensor

1. DTCs P0601, P0602, P0603, P0604, P0606, P0607, P060D, P062F, P1680 and P2610 are not set.
2. The ignition is ON.
3. The ignition voltage is more than 5.23 volts.
4. DTCs P0641 and P0651 run continuously when the above conditions are met.

The control module detects a voltage out of tolerance condition on the 5-volt reference 1 or 2 bus for more than 0.5 second.

DTC P0641 or P0651 are Type A DTCs.

DTC P0641 or P0651 are Type A DTCs.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-poor)
4. «Wiring Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

P0641

1. Observe the 5-volt reference 1 circuit status parameter with a scan tool. The scan tool should display OK.
2. Engine running, observe the DTC information with a scan tool. DTC P0641 should not set.
3. 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 Records data.

P0651

1. Observe the 5-volt reference 2 circuit status parameter with a scan tool. The scan tool should display OK.
2. Engine running, observe the DTC information with a scan tool. DTC P0651 should not set.
3. 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 Records data.

P0641

1. Disconnect the MAP sensor electrical connector.
2. With the ignition ON and the engine OFF, measure for 4.8-5.2 volts between the 5-volt reference circuit terminal C of the MAP sensor and ground. If the voltage is more than 5.2 volts, test for a short to voltage on the 5-volt reference circuits of all the sensors connected to the 5-volt reference 1 bus or a short to voltage on the FTP sensor signal circuit. If the voltage is less than 4.8 volts, test for a short to ground on the 5-volt reference circuits of all the sensors connected to the 5-volt reference 1 bus.
3. Continue to measure the voltage between the 5-volt reference circuit terminal C of the MAP sensor and ground. Monitor the DMM while disconnecting all other sensors connected to the 5-volt reference 1 bus, one at a time. If the voltage returns to 4.8-5.2 volts when a sensor is disconnected, replace the applicable sensor.
4. Reconnect all sensors.
5. Measure for 4.8-5.2 volts between the 5-volt reference circuit terminal B of the A/C refrigerant pressure sensor and ground. If the voltage is not between 4.8-5.2 volts, test for a short to voltage on the MAP sensor signal circuit or a faulty MAP sensor.
6. If all circuits test normal, replace the ECM.

P0651

1. Disconnect the throttle body electrical connector.
2. With the ignition ON and the engine OFF, measure for 4.8-5.2 volts between the 5-volt reference circuit terminal C and ground. If the voltage is more than 5.2 volts, test for a short to voltage on the 5-volt reference circuits on the 5-volt reference 2 bus. If the voltage is less than 4.8 volts, test for a short to ground on the 5-volt reference circuits on the 5-volt reference 2 bus.
3. Continue to measure the voltage between the 5-volt reference circuit terminal C of the throttle body electrical connector and ground. Monitor the DMM while disconnecting APP sensor 1. If the voltage returns to 4.8-5.2 volts when APP sensor 1 is disconnected, replace the APP sensor. If the voltage is not within 4.8-5.2 volts, replace the throttle body assembly.
4. If all circuits test normal, replace the ECM.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Accelerator Pedal Position Sensor Replacement»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2)
2. «Air Conditioning (A/C) Refrigerant Pressure Sensor Replacement»(/cadillac/dts/i-2005-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning)
3. «Control Module References»(/cadillac/dts/i-2005-2011/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, setup, and programming
4. «Exhaust Gas Recirculation Valve Replacement»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2)
5. «Fuel Tank Pressure Sensor Replacement»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2)
6. «Manifold Absolute Pressure Sensor Replacement»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2)
7. «Throttle Body Assembly Replacement»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2)

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provide an overview of each diagnostic category.

The malfunction indicator lamp (MIL) is located on the instrument panel cluster (IPC).

The MIL informs the driver that an emission system fault has occurred and that the engine control system requires service. The control module monitors the MIL control circuit for conditions that are incorrect for the commanded states of the MIL.

1. The system voltage is 9-18 volts.
2. The MIL lamp must be commanded ON for short to battery voltage.
3. The MIL lamp must be commanded OFF for an open or short to ground.
4. DTC P0650 runs continuously when the ignition is ON.

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

DTC P0650 is a Type B DTC.

DTC P0650 is a Type B DTC.

Schematic Reference

1. «Instrument Cluster Schematics»(/cadillac/dts/i-2005-2011/remont/gauges-instrument-panels/#instrument-panel-system-displays-gages)
2. «Engine Controls Schematics»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2)

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-poor)
4. «Wiring Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

1. Ignition ON, command the MIL ON and OFF with a scan tool. The MIL should turn ON and OFF when changing between the commanded states.
2. Ignition ON, observe the scan tool MIL Ckt Status parameters. The reading should indicate OK and continue to indicate OK when commanding the MIL ON and OFF.
3. 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.

1. Ignition OFF, disconnect the harness connector at the instrument panel cluster (IPC).
2. Ignition ON, verify that a test lamp illuminates between the ignition circuit 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, replace the IPC.
3. Connect a test lamp between the control circuit and the ignition circuit.
4. Command the MIL 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 ground. If the circuit tests normal, replace the 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 ECM.
5. If all circuits test normal, replace the IPC.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for control module or IPC replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

EC Ignition Relay Feedback Signal

The Powertrain relay is a normally open relay. The relay switch is held in the open position by spring tension. Battery positive voltage is supplied directly to the relay coil and the relay switch contact at all times. The engine control module (ECM) supplies the ground path to the relay coil control circuit through an output driver module (ODM). The ODM for the powertrain relay also incorporates a fault detection circuit, which is continuously monitored by the ECM. When the ECM commands the powertrain relay ON, ignition 1 voltage is supplied to fuses in the underhood fuse block.

The ignition 1 voltage that is supplied to the ECM, provides power to the internal ECM circuits associated with the throttle actuator control (TAC) operation. The ECM also monitors the voltage level on the ignition 1 voltage circuit to confirm that the powertrain relay contacts have closed.

P0685

1. The battery voltage is between 9-18 volts.
2. The ignition is ON.
3. The powertrain relay has been commanded ON.

P0690

1. The battery voltage is between 9-16 volts.
2. The ignition is OFF.
3. The powertrain relay has been commanded OFF.

P0685

1. The commanded state of the ODM does not match and the actual state of the control circuit.
2. The condition is present for more than 5 seconds.

P0690

1. The ECM detects more than 2 volts on the ignition 1 voltage circuit to the ECM.
2. The condition is present for more than 2 seconds.

1. The control module stores the DTC information into memory when the diagnostic runs and fails.
2. The malfunction indicator lamp (MIL) will illuminate.
3. The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in failure records.
4. The driver information center (DIC), if equipped, may display a message.

1. A current DTC, last test failed clears when the diagnostic runs and passes.
2. A history DTC clears after 40 consecutive warm up cycles, if this or any other related diagnostic reports no other failures.
3. Clear the DTC with a scan tool.

1. This test procedure assumes that the vehicle battery has passed a load test and is completely charged. Refer to «Battery Inspection/Test»(/cadillac/dts/i-2005-2011/remont/charging-system/#battery-charging-system-and-starting-system) .
2. When disconnecting electrical connectors or removing fuses and relays from a fuse block, always inspect the component electrical terminals for corrosion and the mating electrical terminals for correct tension.

Schematic Reference

1. «Engine Controls Schematics»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2)
2. «Power Distribution Schematics»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-introduction)

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-poor)
4. «Wiring Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Special Tools

J 43244 Relay Puller Pliers. See Special Tools .

1. With the ignition ON, engine OFF, command the powertrain relay ON and OFF several times using the scan tool output control function, engine controls ignition relay selection. You should either hear or feel the relay click with each command.
2. With the ignition ON, engine OFF, probe both test points of each of the fuses supplied with voltage by the powertrain relay. The test lamp should illuminate on at least one test point of each fuse. If the test lamp does not illuminate continue with Circuit/System Testing.
3. Engine running, observe the DTC information with a scan tool. DTCs P0685 or P0690 should not set.
4. 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.

1. With the ignition OFF, remove the powertrain relay from the underhood fuse block using the J 43244 . See «Special Tools»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2) .
2. With the ignition ON, measure for battery positive voltage, B+, between the battery supply voltage coil circuit and ground. If the voltage measures less than B+, repair the open or high resistance in the circuit to the relay coil. All wire circuit resistance should measure less than 2 ohms.
3. Measure for voltage between the powertrain relay control circuit and ground. If voltage is measured on the control circuit of the relay, test for a short to voltage.
4. Connect a test lamp between the battery supply voltage coil and the powertrain relay control circuit. Use a scan tool to command the powertrain relay ON and OFF using engine controls ignition relay selection. The test lamp should turn ON and OFF when toggling between the commanded states. If the test lamp stays ON all the time, test for a short to ground on the powertrain relay control circuit. If the circuit tests normal, replace the control module. If the test lamp stays OFF all the time, test for an open or high resistance on the powertrain relay control circuit. If the circuit tests normal, replace the control module. All wire circuit resistance should measure less than 2 ohms.
5. Measure for B+ between the relay battery supply voltage armature circuit, and ground. If the voltage measures less than B+, repair the open or high resistance in the circuit to the relay armature. All wire circuit resistance should measure less than 2 ohms.
6. With the ignition ON, test for voltage on each test point of the CRNK fuse. If voltage is present, test the ignition 1 voltage circuit between the ECM/CRNK, the powertrain relay, and the ECM/CRNK fuse for a short to voltage. If both circuits test normal, replace the ECM.
7. Connect a 20A fused jumper wire between the B+ terminal and the ignition 1 voltage terminal of the powertrain relay at the underhood fuse block. With a test lamp, probe both test points of the ECM/CRNK fuse. If the test lamp illuminates at both test points of the ECM/CRNK fuse, repair the ignition 1 voltage circuit between the powertrain relay and the ECM/CRNK for an open or high resistance. If the circuit tests normal, replace the control module. All wire circuit resistance should measure less than 2 ohms. If the test lamp only illuminates at one test point of the ECM/CRNK fuse, repair the short to ground in the ignition 1 voltage circuit between the fuse and the applicable component. Replace the fuse, as necessary. If the test lamp does not illuminate on either test point of the ECM/CRNK fuse, repair the open or high resistance between the powertrain relay and the ECM/CRNK fuse. All wire circuit resistance should measure 2 ohms or less.

1. Measure for 70-110 ohms between terminals 85 and 86 of the relay. If the resistance is not within the specified range, replace the relay.
2. Measure for infinite resistance between terminals 30 and 86 of the relay. If continuity is detected, replace the relay.
3. Measure for infinite resistance between terminals 30 and 87 of the relay. If continuity is detected, replace the relay.
4. Measure for infinite resistance between terminals 30 and 85 of the relay. If continuity is detected, replace the relay.
5. Measure for infinite resistance between terminals 85 and 87 of the relay. If continuity is detected, replace the relay.
6. Connect a 20A fused jumper wire from the battery positive cable at the battery, to relay terminal 85. Connect a jumper wire from the negative battery cable at the battery, to relay terminal 86. Measure for less than 2 ohms between terminals 30 and 87 of the relay, with a DMM. If the resistance measures more than 2 ohms, replace the relay.

Perform the Diagnostic Repair Verification after completing the repair.

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

This diagnostic trouble code (DTC) 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.

1. The ignition is ON.
2. DTC P0700 runs continuously.

Serial Data communication from the TCM indicates a fault exists with the transmission.

1. The control module illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame/Failure Records.

1. The ECM turns OFF the malfunction indicator lamp (MIL) when it no longer receives a MIL request from the TCM.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

1. DTC P0700 is an informational DTC. If there are engine controls DTCs, diagnose those first. Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-trouble-code-dtc-list) . For diagnosis of TCM DTCs, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-trouble-code-dtc-list) .
2. Engine running, observe the DTC information with a scan tool. DTC P0700 should not set.
3. 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 Records data.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provide an overview of each diagnostic category.

The engine control module (ECM) detects engine misfire by detecting variations in crankshaft deceleration between firing strokes. For accurate detection of engine misfire, the ECM must distinguish between crankshaft deceleration caused by actual misfire and deceleration caused by rough road conditions. The antilock brake system (ABS) can detect if the vehicle is on a rough road based on wheel acceleration/deceleration data supplied by the wheel speed sensor. If the ABS detects rough road above a predetermined threshold, this information is sent to the ECM. The ECM uses the rough road information when calculating engine misfire. If the ABS is malfunctioning and cannot detect rough roads, the misfire diagnostic will continue to run. However, if an engine misfire DTC sets, this DTC also sets indicating that rough road data was not available or there was no communication with the brake control module during the misfire calculation due to an ABS malfunction.

P1380

1. The vehicle speed is more than 0 km/h.
2. DTC P1380 runs continuously once the above condition has been met.

P1381

DTC P1381 runs continuously

P1380

1. The ABS controller sends a message to the ECM indicating that a failure has occurred in the ABS module.
2. DTC P0300 is set.

P1381

1. An ABS malfunction exists, preventing the ECM from receiving rough road detection data.
2. DTC P0300 is set.

DTCs P1380 and P1381 are Type C DTCs.

DTCs P1380 and P1381 are Type C DTCs.

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

1. Monitor the ABS DTCs on the scan tool. If any ABS DTCs are set, diagnose those first. Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-trouble-code-dtc-list) . If there are no ABS DTCs set, refer to «Symptoms - Antilock Brake System»(/cadillac/dts/i-2005-2011/remont/anti-locktraction-control/#anti-lock-brake-system-traction-control-system-stability-control-system__symptoms-antilock-brake-system) .
2. 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.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provide 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

1. Engine speed
2. Spark advance
3. Throttle position
4. Engine airflow
5. Engine coolant temperature
6. Engine run time
7. Park/Neutral position
8. Vehicle speed

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

1. The engine is running, and a cold start has been detected.
2. The vehicle speed is less than 2 km/h (1 mph).
3. The throttle position sensor is less than 2 percent.
4. The airflow per cylinder is greater than 40 mg.
5. DTCs P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0220, P0222, P0223, P0201-P0208, P0300, P0301-P0308, P0335, P0336, P0351-P0358, P0506, P0507, P0601, P0602, P0604, P0606, P0607, P060D, P062F, P0641, P0651, P1516, P1682, P2101, P2119, P2120, P2122, P2123, P2125, P2127, P2128, P2135, P2138, P2176, or P2610 are not set.

1. The average accumulated exhaust energy model is not within a calibrated range to the estimated average exhaust energy model. The average accumulated exhaust energy is less than -11 kj/s or greater than 0.25 kj/s of the estimated average accumulated exhaust energy.
2. This DTC runs within 10 seconds of start-up. This diagnostic runs once per trip when a cold start has been determined.

DTC P1400 is a Type A DTC.

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.

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

1. Allow the engine to cool.
2. Start and idle the engine for at least 2 minutes.
3. DTC P1400 should run and pass.
4. Engine running, observe the DTC information with a scan tool. DTC P1400 should not set.
5. 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.

1. Inspect the air intake system for the following: Damage, restriction, or modification 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
2. Inspect the exhaust system for the following: Water intrusion Exhaust leak Damaged, restricted, modified or enhanced exhaust system.
3. Inspect the engine mechanical for items that could alter the air flow into the combustion chamber.

Perform the Diagnostic Repair Verification after completing the repair.

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The engine control module (ECM) is the control center for the throttle actuator control (TAC) system. The ECM determines the drivers intent and then calculates the appropriate throttle response. The ECM achieves throttle positioning by providing a pulse width modulated voltage to the TAC motor. The TAC system uses the following circuits

1. Motor control 1
2. Motor control 2

Two processors are also used to monitor the TAC system data. Both processors are located within the ECM. Both processors monitor each other's data to verify that the indicated throttle position is correct.

P1516 and P2101

1. DTC P0068 or P0121 are not set.
2. The ignition is ON.
3. The ignition voltage is greater than 11 volts.
4. The system is not in the Battery Save mode.
5. The engine is running.
6. DTC P1516 and P2101 run continuously when the above conditions are met.

P2119

1. The ignition is ON.
2. The ignition voltage is greater than 8 volts.
3. The system is in the Battery Save mode.
4. DTC P2119 runs continuously when the above conditions are met.

P2176

1. DTC P0068, P0120, P0122, P0123, P0220, P0222, or P0223 are not set.
2. The ignition is ON.
3. The ignition voltage is greater than 8 volts.
4. The system is not in the Battery Save mode.
5. The engine is running.
6. DTC P2176 run continuously when the above conditions are met.

P1516

The indicated throttle position does not match the predicted throttle position for greater than 0.2 second.

P2101

The indicated throttle position does not match the predicted throttle position for greater than 0.1 second.

P2119

The ECM determines that the throttle blade did not return to the rest position within 720 milliseconds.

P2176

The difference between the predicted and the actual throttle position is greater than a calibrated amount for greater than 1.8 seconds.

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

1. DTCs P1516, P2101, and P2176 are Type A DTCs.
2. DTC P2119 is a Type C DTC.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Throttle Actuator Control (TAC) System Description

Electrical Information Reference

1. «Circuit Testing»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-poor)
4. «Wiring Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

1. Ignition ON, use a scan tool to observe the throttle position (TP) sensor 1 indicated position. The throttle position should increase as the pedal is applied, and decrease as the pedal is released. When no accelerator pedal activity is detected, the throttle position will return to the spring loaded default position.
2. Engine running, observe the DTC information with a scan tool. DTCs P1516, P2101, P2119 or P2176 should not set.
3. 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.

1. Inspect the throttle body for the following conditions: A throttle blade that is NOT in the rest position A throttle blade that is binding when open or closed A throttle blade that is free to move open or closed WITHOUT spring pressure If a condition is found replace the throttle body assembly.
2. Ignition OFF, disconnect the harness connector at the throttle body.
3. Ignition ON, verify that a test lamp does not illuminate between motor control 1 circuit terminal B and ground. If a test lamp illuminates, test the motor control circuit for a short to voltage. If the circuit tests normal, replace the ECM.
4. Ignition ON, verify that a test lamp does not illuminate between motor control 2 circuit terminal A and ground. If a test lamp illuminates, test the motor control circuit for a short to voltage. If the circuit tests normal, replace the ECM.
5. Ignition ON, verify that a test lamp does not illuminate between motor control 1 circuit terminal B and B+. If a test lamp illuminates, test the motor control circuit for a short to ground. If the circuit tests normal, replace the ECM.
6. Ignition ON, verify that a test lamp does not illuminate between motor control 2 circuit terminal A and B+. If the test lamp illuminates, test the motor control circuit for a short to ground. If the circuit tests normal, replace the ECM.
7. Ignition OFF, allow sufficient time for the ECM to completely power down. Connect a DMM between the motor control 1 circuit terminal B and ground.
8. Measure for ignition voltage on the motor control 1 terminal B circuit as the ignition is turned ON. If voltage is not within 1 volt of B+, test the circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
9. Ignition OFF, allow sufficient time for the ECM to completely power down. Connect a DMM between the motor control 2 terminal A circuit and ground.
10. Measure the voltage on the motor control 2 terminal A circuit as the ignition is turned ON. Voltage should be within 1 volt of ignition voltage. If the peak voltage is not within 1 volt of B+, test the circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
11. If all circuits test normal, replace the throttle body.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Control Module References»(/cadillac/dts/i-2005-2011/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, setup, and programming
2. «Throttle Body Assembly Replacement»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2)

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

EC Ignition Relay Feedback

Ignition 1 Signal

There are 2 ignition 1 voltage circuits supplied to the engine control module (ECM). The first ignition 1 voltage circuit is provided by the powertrain relay, through a fuse. This ignition 1 voltage circuit supplies power to all the internal ECM circuits associated with the throttle actuator control (TAC) operation. The run/crank relay provides the second ignition 1 voltage circuit to the ECM, through a fuse. This ignition 1 voltage provides power to other internal ECM circuits, except those associated with TAC operation. The ECM continuously monitors the voltage level difference between the 2 circuits.

1. The ignition is in the Unlock/Accessory, Run, or Crank position.
2. System voltage is more than 5.23 volts.
3. The powertrain relay is commanded ON.
4. DTC P1682 runs continuously when the above conditions are met.

The ignition 1 voltage of the Run/Crank relay is more than 3 volts different than the ignition 1 voltage of the powertrain relay for more than 1 second.

1. DTC P1682 is a Type A DTC.
2. Engine may operate in a reduced engine power mode.

DTC P1682 is a Type A DTC.

This test procedure requires that the vehicle battery has passed a load test and is completely charged. Refer to Battery Inspection/Test .

Schematic Reference

1. «Engine Controls Schematics»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2)
2. «Power Distribution Schematics»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-introduction)

Connector End View Reference

Component Connector End Views

Description and Operation

Engine Control Module Description

Electrical Information Reference

1. «Circuit Testing»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-poor)
4. «Wiring Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)
5. «Probing Electrical Connectors»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__probing-electrical-connectors)
6. «Electrical Center Identification Views»(/cadillac/dts/i-2005-2011/remont/electrical-component-locations/#wiring-systems-and-power-management-component-locator-component-connector-end-views)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

1. If DTCs P0685, P0689, or P0690 are set, diagnose those DTCs first.
2. Ignition ON, engine OFF, observe the Ignition 1 voltage signal, and the EC Ignition Relay Feedback signal parameters, on the scan tool. Both parameter values should display no more than 3 volts difference, between the 2 parameters.
3. Ignition OFF, observe the ignition 1 voltage signal parameter, on the scan tool. The parameter value should be 0 volts, before the ECM powers down.
4. Engine running, observe the DTC information with a scan tool. DTC P1682 should not set.
5. 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.

1. Ignition ON, observe the Ignition 1 Signal and EC Ignition Relay Feedback scan tool parameters to determine which is less than B+.
2. Ignition OFF, remove the relay that corresponds to the scan tool parameter that is less than B+.
3. Ignition ON, connect a 3A fused jumper wire between B+ and the applicable ignition 1 circuit terminal. Verify that the applicable scan tool parameter displays B+. If the applicable scan tool parameter is less than the specified value, test the ignition 1 circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
4. If all circuits test normal, test or replace the applicable relay.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for ECM replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provide an overview of each diagnostic category.

APP Sensor 1

APP Sensor 2

The accelerator pedal position (APP) sensor is mounted on the accelerator pedal control assembly. Two APP sensors, APP sensors 1 and 2, are used to monitor the accelerator pedal position. Each sensor has a 5-volt reference circuit, low reference circuit, and a signal circuit.

Two processors are also used to monitor the TAC system data. Both processors are located within the engine control module (ECM). Each signal circuit provides both processors with a signal voltage proportional to pedal movement. The processors share and monitor data to verify that the indicated APP calculation is correct.

Conditions for Running DTC

P2120, P2122, P2123, P2125, P2127, P2128

1. DTC P0601, P0602, P0603, P0604, P0606, P060D, P062F, P0641, or P0651 are not set.
2. The ignition is ON.
3. The battery voltage is greater than 5.23 volts.
4. DTC P2122, P2123, P2127, P2128 run continuously when the above conditions are met.

P2138

1. DTC P0601, P0602, P0603, P0604, P0606, P060D, P062F, P0641, P0651, P2120, P2122, P2123, P2125, P2127 or P2128 are not set.
2. The ignition is ON.
3. The battery voltage is greater than 5.23 volts.
4. DTC P2138 runs continuously when the above conditions are met.

P2120

The ECM detects that the APP sensor 1 voltage is less than 0.33 volt or greater than 4.5 volts for less than 1 second.

P2122

The ECM detects that the APP sensor 1 voltage is less than 0.33 volt for less than 1 second.

P2123

The ECM detects that the APP sensor 1 voltage is greater than 4.5 volts for less than 1 second.

P2125

The ECM detects that the APP sensor 2 voltage is less than 0.33 volt or greater than 4.5 volts for less than 1 second.

P2127

The ECM detects that the APP sensor 2 voltage is less than or equal to 0.33 volt for less than 1 second.

P2128

The ECM detects that the APP sensor 2 voltage is greater than 4.5 volts for less than 1 second.

The voltage difference between APP sensor 1 and APP sensor 2 exceeds a value of 5 percent with the pedal in the released position, or 10 percent with the pedal at wide open throttle (WOT) for less than 1 second.

1. DTCs P2120, P2122, P2123, P2125, P2127, P2128, and P2138 are Type A DTCs.
2. The control module commands the TAC system to operate in the Reduced Engine Power mode.
3. A message center or an indicator displays Reduced Engine Power.
4. Under certain conditions the control module commands the engine OFF.

DTCs P2120, P2122, P2123, P2125, P2127, P2128, and P2138 are Type A DTCs.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-poor)
4. «Wiring Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

Description and Operation

Throttle Actuator Control (TAC) System Description

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

1. Ignition ON, observe the scan tool APP sensor 1 voltage parameter. The reading should be between 0.13-4.87 volts, and change with accelerator pedal input.
2. Ignition ON, observe the scan tool APP sensors 2 voltage parameter. The reading should be between 0.13-4.87 volts and change with accelerator pedal input.
3. Ignition ON, observe the scan tool APP sensors 1 and 2 parameter. The scan tool should indicate agree.
4. Clear the DTCs with the scan tool. Operate the vehicle within the Conditions for Running the DTC, or within the conditions that you observed from the Freeze Frame/Failure Records.
5. Verify that DTCs P2120 or P2125 are not the only throttle position DTCs set. If DTCs P2120 or P2125 are the only DTCs set, replace the ECM.
6. Verify that DTCs P0641 or P0651 are not set. If DTCs P0641 or P0651 are set, refer to «DTC P0641 or P0651»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-dtc-p0340-to-dtc-p2138) .

1. Ignition OFF, disconnect the harness connector at the accelerator pedal. Allow at least 90 seconds for the ECM to power down. This can be verified by a loss of communication message on the scan tool.
2. Test for less than 5 ohms of resistance between each low reference circuit terminals A and D and ground. If greater than 5 ohms, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
3. Ignition ON, test for 4.8-5.8 volts between each 5-volt reference circuit terminals C and F and ground. If less than 4.8 volts, test the affected 5-volt reference circuit for an open/high resistance or short to ground. If the circuit tests normal, replace the ECM. If greater than 5.2 volts, test the affected 5-volt reference circuit for short to voltage. If the circuit test normal, replace the ECM.
4. Ignition ON, verify the scan tool APP sensor 1 and 2 voltages are less than 0.1 volt. If greater than 0.1 volt, test the APP sensor 1 and 2 signal circuits terminals B and E for a short to voltage. If the circuit tests normal, replace the ECM.
5. Install a 3A fused jumper wire between the signal circuit terminal E and the 5-volt reference circuit terminal F of the APP sensor 1. Verify the scan tool parameter APP sensor 1 voltage is greater than 4.8 volts. If less than 4.8 volts, test the APP sensor 1 signal circuit for an open or short to ground. If the circuit tests normal, replace the ECM.
6. Install a 3A fused jumper wire between the signal circuit terminal B and the 5-volt reference circuit terminal C of the APP sensor 2. Verify that the scan tool parameter APP sensor 2 voltage is greater than 4.8 volts. If less than 4.8 volts, test the APP sensor 2 signal circuit for an open/high resistance or short to ground. If the circuit tests normal, replace the ECM.
7. Ignition OFF, disconnect the X1 harness connector at the ECM.
8. Test for less than 5 ohms of resistance on all APP sensor circuits between the following terminals: ECM X1 signal circuit terminal 47 to APP terminal E ECM X1 signal circuit terminal 49 to APP terminal B ECM X1 5-volt reference circuit terminal 35 to APP terminal C ECM X1 5-volt reference circuit terminal 33 to APP terminal F If greater than 5 ohms, repair the affected circuit for an open/high resistance.
9. Test for infinite resistance between APP sensor 1 signal circuit terminal E and APP sensor 2 signal circuit terminal B. If less than infinite resistance, repair the short between APP sensor 1 signal circuit and APP sensor 2 signal circuits.
10. If all circuits test normal, test or replace the APP sensor. If the APP sensor tests normal, replace the ECM.

Component Test

Dynamic Test

1. Install a 3A fused jumper wire between the 5-volt reference terminal of the applicable APP sensor and 5 volts. Install a jumper wire between the low reference terminal and a ground.
2. Sweep the sensor through the entire range while monitoring the voltage between the signal terminal and the low reference terminal with a DMM. The voltage should vary between 0.30-4.98 volts without any spikes or dropouts. If the voltage is not within the specified range or is erratic, replace the accelerator pedal assembly.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Accelerator Pedal Position Sensor Replacement»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2)
2. «Control Module References»(/cadillac/dts/i-2005-2011/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, setup, and programming

See also:
• Diagnostic System Check - Vehicle
• Strategy Based Diagnosis
• Diagnostic Procedure Instructions
• Engine Controls Schematics
• Component Connector End Views
• Circuit Testing
• Connector Repairs
• Testing for Intermittent Conditions and Poor Connections
• Wiring Repairs
• Powertrain Diagnostic Trouble Code (DTC) Type Definitions
• Control Module References
• Diagnostic Repair Verification
• Diagnostic Trouble Code (DTC) List - Vehicle
• Symptoms - Engine Mechanical
• Altitude Versus Barometric Pressure
• Heated Oxygen Sensor Resistance Learn Reset Notice
• Three-Way Catalytic Converter Damage Notice
• Exhaust System Replacement
• Troubleshooting with a Test Lamp
• Throttle Body Inspection and Cleaning
• Service Programming System (SPS)
• Air Conditioning (A/C) Refrigerant Pressure Sensor Replacement
• Instrument Cluster Schematics
• Battery Inspection/Test
• Power Distribution Schematics
• Symptoms - Antilock Brake System
• Engine Control Module Description
• Probing Electrical Connectors
• DTC P0420