Engine Control System &amp; Fuel - 4.8l, 5.3l, 6.0l or 6.2l - DTC p0230 to DTC p0690 Chevrolet Avalanche II

Connector End View Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
«Connector Repairs»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Special Tools

J 43244 Relay Puller Pliers. See Special Tools .

Circuit/System Verification (w/LY6)

IMPORTANT

An open or a short to voltage in the control circuit will cause both the Ckt. Open Test Status and the Ckt. Short Volts Test Status parameters to display Fault.

Ignition ON, command the fuel pump relay ON and OFF with a scan tool while observing the following control circuit status parameters: Fuel Pump Relay Ckt. Short Gnd Test Status Fuel Pump Relay Ckt. Open Test Status Fuel Pump Relay Ckt. Short Volts Test Status
Each parameter should toggle between OK and Not Run or Not Run and OK.

Circuit/System Testing (w/LY6)

Ignition OFF, disconnect the fuel pump relay.
Ignition ON, verify that a test lamp illuminates between the ground circuit terminal and B+. If the test lamp does not illuminate, test the ground circuit for a short to voltage or an open/high resistance.
Verify that a test lamp does not illuminate between the ground circuit terminal and the control circuit terminal. If the test lamp illuminates, test the control circuit for a short to voltage. If the circuit tests normal, replace the ECM.
Remove the test lamp.
Command the fuel pump relay ON with a scan tool. Verify the scan tool fuel pump relay Ckt. Short Grnd Test Status parameter is OK. If not the specified value, test the fuel pump relay control circuit for a short to ground. If the circuit tests normal, replace the ECM.
Install a 3A fused jumper wire between the fuel pump relay control circuit terminal and the ground circuit terminal. Command the fuel pump ON with a scan tool. Verify the scan tool fuel pump relay Ckt. Short Grnd Test Status parameter is Fault. If not the specified value, test the fuel pump relay control circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
If all circuits test normal, test or replace the fuel pump relay.

Repair Procedures (w/LY6)

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

«Relay Replacement (Attached to Wire Harness)»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-introduction) or «Relay Replacement (Within an Electrical Center)»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-introduction)
«Control Module References»(/chevrolet/avalanche/ii-2006-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, setup, and programming

Diagnostic Instructions

Perform the «Diagnostic System Check - Vehicle (with HP2)»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-system-check-vehicle-with) or «Diagnostic System Check - Vehicle (without HP2)»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-system-check-vehicle-without) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Diagnostic Fault Information

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

Circuit/System Description

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

P0231, P023F

The ignition voltage is between 9-18 volts

P0232

The control enable voltage signal supplied for the ECM to FPCM is inactive for 4 seconds after engine has been shut off.

Conditions for Setting the DTC

The FPCM detects a fault on the fuel pump voltage circuit that is above or below a predetermined voltage threshold.

Actions Taken When the DTC Sets

DTCs P0231, P0232, and P023F are Type A DTCs.

Conditions for Clearing the DTC

DTCs P0231, P0232, and P023F are Type A DTCs.

Diagnostic Aids

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

Reference Information

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Description and Operation

Fuel System Description

Electrical Information Reference

«Circuit Testing»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
«Connector Repairs»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

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

Circuit/System Testing

Ignition OFF, disconnect the harness connector at the fuel pump.
Connect a test lamp between the control circuit terminal D and ground.
Ignition ON, command the fuel pump ON and OFF using a scan tool ECM fuel pump output control. The test lamp should turn ON and OFF, as commanded. If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the FPCM. If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the FPCM.
Ignition OFF, connect a test lamp between the control circuit terminal A and the control circuit terminal D.
Ignition ON, command the fuel pump ON using a scan tool. The test lamp should illuminate. If the test lamp does not illuminate, test the control circuit terminal A for a short to voltage or an open/high resistance. If the circuit tests normal, replace the FPCM.
If all circuits test normal, perform the «Fuel System Diagnosis (w/o FPCM)»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-troubleshooting-diagnosis) or «Fuel System Diagnosis (w/FPCM)»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-troubleshooting-diagnosis) to verify proper fuel pressure.

Repair Procedures

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

«Fuel Tank Fuel Pump Module Replacement»(ref-339158-S01457080882009090300000)
«Control Module References»(/chevrolet/avalanche/ii-2006-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for FPCM replacement, setup, and programming

Perform the «Diagnostic System Check - Vehicle (with HP2)»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-system-check-vehicle-with) or «Diagnostic System Check - Vehicle (without HP2)»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-system-check-vehicle-without) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Circuit	Short to Ground	Open or High Resistance	Short to Voltage	Signal Performance
FPCM Control	P025A	P025A

Conditions for Running the DTC

The ignition is ON.

The serial data message from the ECM to the FPCM does not agree with the state of the control enable circuit voltage supplied from the ECM to the FPCM for more than 2 seconds.

Action Taken When the DTC Sets

DTC P025A is a Type A DTC.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Description and Operation

Fuel System Description

Electrical Information Reference

«Circuit Testing»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
«Connector Repairs»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Ignition OFF, disconnect the harness connector at the FPCM.
Ignition OFF, connect a test lamp between the control circuit terminal 13 and ground.
Ignition ON, command the fuel pump ON and OFF using the scan tool ECM fuel pump output control. The test lamp should turn ON and OFF when changing between the commanded states. If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the ECM. If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM.
If all circuits test normal, replace the FPCM.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for ECM or FPCM replacement, setup, and programming

Perform the «Diagnostic System Check - Vehicle (with HP2)»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-system-check-vehicle-with) or «Diagnostic System Check - Vehicle (without HP2)»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-system-check-vehicle-without) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The engine control module (ECM) uses information from the crankshaft position (CKP) sensor in order to determine when an engine misfire is occurring, and uses information from the camshaft position (CMP) sensor in order to determine which cylinder is misfiring. By monitoring variations in the crankshaft rotation speed for each cylinder, the ECM is able to detect individual misfire events. If the ECM detects a misfire rate sufficient to cause emission levels to exceed mandated standards, DTC P0300 sets. Under certain driving conditions, a misfire rate can be high enough to cause the catalytic converter to overheat, possibly damaging the converter. The malfunction indicator lamp (MIL) will flash ON and OFF when catalytic converter overheating conditions are present and DTC P0300 is set. DTCs P0301-P0308 corresponds to cylinders 1-8. If the ECM is able to determine that a specific cylinder is misfiring, the DTC for that cylinder will also set.

DTC P0010, P0011, P0016, P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0122, P0123, P0128, P0220, P0222, P0223, P0335, P0336, P0606, P0641, P0651, P1516, P2101, P2119, P2120, P2122, P2123, P2125, P2127, P2128, P2135, P2138, P2176, P3401, P3425, P3441, and P3449 are not set.
The engine speed is between 375-5,800 RPM and DTC P0315 is not set. OR
The engine speed is greater than 1,000 rpm and DTC P0315 is set.
The ignition voltage is between 9-18 volts.
The engine coolant temperature (ECT) is between -7 and +130°C (+19 and +266°F).
If the ECT is less than -7°C (+19°F) at startup this diagnostic will not run until the ECT is more than +21°C (+69°F).
The fuel level is more than 10 percent.
The antilock brake system (ABS) and the traction control system (TCS) are not active or detecting rough road.
The power management is not active.
The ECM is not in fuel shut-off, or decel fuel cut-off mode.
Excessive drive wheel slip is not detected.
The power take-off (PTO) is disabled.
The cylinder deactivation is not in progress.
A manual transmission with a throttle position less than 95 percent.
DTCs P0300-P0308 run continuously when the above conditions are met.

The ECM is detecting a crankshaft rotation speed variation indicating a misfire sufficient to cause emission levels to exceed mandated standards.

DTCs P0300-P0308 are Type B DTCs.
When the MIL is flashing the fuel injector may be disabled for the misfiring cylinder to protect the catalytic converter.
Depending on the conditions that set the DTC, the engine may go into Open Loop.

Conditions for Clearing the MIL/DTC

DTCs P0300-P0308 are Type B DTCs.
The DTC must run and pass under the same operating conditions that were present when the DTC failed.

Ensure that each fuel injector is connected to the proper fuel injector harness connector.
A misfire may only occur when the engine is operating under a load or when the engine is cold.
A high resistance condition on any ignition control (IC) circuit can cause an engine misfire P0300-P0308 DTC to set without setting an IC circuit P0351-P0358 DTC.
This test procedure requires that the vehicle battery has passed a load test and is completely charged. Refer to «Battery Inspection/Test»(/chevrolet/avalanche/ii-2006-2013/remont/charging-system/#battery-charging-system-and-starting-system) .
A misfire DTC could be caused by an excessive vibration from sources other than the engine. Inspect the following for possible sources of vibration: A tire or wheel that is out of round or balance Variable thickness brake rotors An unbalanced drive shaft Certain rough road conditions A damaged accessory drive component or belt A damaged reluctor wheel The Crankshaft Position System Variation Learn procedure may need to be performed.

Schematic Reference

Connector End View Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
«Connector Repairs»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Special Tools

J 26792 HEI Spark Tester. See Special Tools .

Verify that no other DTCs are set. If a DTC is set, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-trouble-code-dtc-list) .
Engine idling, verify there is no abnormal engine noise. If there is an abnormal engine noise, refer to «Symptoms - Engine Mechanical»(/chevrolet/avalanche/ii-2006-2013/remont/mechanical/#engine-mechanical-48l-53l-60l-or-62l-1-of-5) .
Observe the Misfire Current Counters with a scan tool. The Misfire Current Counters should not be incrementing. A random misfire, across one or more cylinders that are not steadily incrementing may be normal for this engine.
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.

IMPORTANT

You must perform the Circuit/System Verification first.

Verify that the following conditions do not exist: The fuel injector wire harness electrical connectors are connected to the wrong fuel injectors. Refer to «Engine Controls Schematics»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction) . Engine vacuum leaks Fuel pressure that is too low or too high-Refer to «Fuel System Diagnosis (w/o FPCM)»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-troubleshooting-diagnosis) or «Fuel System Diagnosis (w/FPCM)»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-troubleshooting-diagnosis) . Contaminated fuel-Refer to «Alcohol/Contaminants-in-Fuel Diagnosis (without Special Tool)»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-troubleshooting-diagnosis) or «Alcohol/Contaminants-in-Fuel Diagnosis (with Special Tool)»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-troubleshooting-diagnosis) . Restricted exhaust system-Refer to «Restricted Exhaust»(/chevrolet/avalanche/ii-2006-2013/remont/exhaust/#engine-exhaust-system) . The cylinder deactivation system, for misfire on either cylinders 1, 4, 6, or 7-Refer to «Cylinder Deactivation (Active Fuel Management) System Diagnosis»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-troubleshooting-diagnosis) .
Measure the resistance of the spark plug wire, and verify the condition of the spark plug wire. Refer to «Ignition System Specifications»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction__ignition-system-specifications) and «Spark Plug Wire Inspection»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction__spark-plug-wire-inspection) . If the resistance value is not within the specified range, or does not pass the inspection, replace the spark plug wire.
Reinstall the spark plug wire to the ignition module/coil assembly.
Install the J 26792 to the spark plug wire boot. See «Special Tools»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction) .
Attempt to start the engine and observe the J 26792 . See «Special Tools»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction) . The spark plug tester should spark. If there is no spark, refer to «Electronic Ignition System Diagnosis»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-troubleshooting-diagnosis) .
Ignition OFF, remove the spark plug from the misfiring cylinder. Verify that the following conditions do not exist with the spark plug: Gas, coolant, or oil fouled Cracked, worn, or incorrectly gapped-Refer to «Spark Plug Inspection»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction__spark-plug-inspection) . If there is a condition with the spark plug, replace the spark plug.
Exchange the suspected spark plug with another cylinder that is operating correctly.
Operate the engine under the conditions in which the misfire occurred, this may include putting the engine under a load or allowing the engine to return to a cold condition. Observe the Misfire Current Counters with a scan tool. The misfire should not follow the spark plug exchange. If the misfire follows with the spark plug, replace the spark plug.
If all conditions test normal, test or inspect for the following: A lean or rich fuel injector-Refer to «Fuel Injector Diagnosis (w/CH47976)»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-troubleshooting-diagnosis) or «Fuel Injector Diagnosis (w/J39021 or w/Tech 2)»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-troubleshooting-diagnosis) . An engine mechanical condition-Refer to «Symptoms - Engine Mechanical»(/chevrolet/avalanche/ii-2006-2013/remont/mechanical/#engine-mechanical-48l-53l-60l-or-62l-1-of-5) .

«Spark Plug Replacement»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction)
«Spark Plug Wire Replacement»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction)
«Ignition Coil Replacement»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction)

Repair Verification

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

Install any components that have been removed or replaced during diagnosis.
Perform any adjustments, programming or setup procedures that are required when a component is removed or replaced.
Clear the DTCs.
Turn OFF the ignition for 60 seconds.
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»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-trouble-code-dtc-list) and perform the appropriate diagnostic procedure.
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 DTCs P0420 and P0430. Refer to «DTC P0420 or P0430»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-dtc-p0230-to-dtc-p0690) .

Perform the «Diagnostic System Check - Vehicle (with HP2)»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-system-check-vehicle-with) or «Diagnostic System Check - Vehicle (without HP2)»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-system-check-vehicle-without) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The crankshaft position (CKP) system variation learn feature is used to calculate reference period errors caused by slight build tolerance variations in the CKP sensor, crankshaft, and CKP sensor position. The calculated error allows the engine control module (ECM) to accurately compensate for reference period variations. This enhances the ability of the ECM to detect misfire events over a wide range of engine speeds and load conditions. The ECM stores the Crankshaft Position System Variation values after a learn procedure has been performed. If the actual crankshaft position variation is not stored within the CKP compensating value look up table, then DTC P0300 may set. If the CKP system variation values are not stored in the ECM memory, or a proper ECM power down does not occur after completing the CKP Learn Procedure, then DTC P0315 sets.

The diagnostic runs continuously.

The ECM detects that the CKP system variation values are not stored in memory.

DTC P0315 is a Type A code.

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

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

IMPORTANT

The CKP System Variation Learn Procedure may have to be repeated up to 5 times before the procedure is learned.

Perform the CKP System Variation Learn Procedure. Refer to «Crankshaft Position System Variation Learn»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction__crankshaft-position-system-variation-learn) .
If the CKP System Variation Learn Procedure cannot be performed successfully, inspect for the following conditions: Any worn crankshaft main bearings A damaged or misaligned reluctor wheel Excessive crankshaft runout A damaged crankshaft-Refer to «Crankshaft and Bearing Cleaning and Inspection»(/chevrolet/avalanche/ii-2006-2013/remont/mechanical/#engine-mechanical-48l-53l-60l-or-62l-3-of-5) . Interference in the signal circuit of the CKP sensor The ignition switch is left in the ON position, until the battery is discharged An ECM power disconnect, with the ignition ON, that may have erased the CKP system variation values and set DTC P0315 Any debris between the CKP sensor and the reluctor wheel If the ECM is still unable to complete the learn procedure, replace the ECM.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

«Engine Control Module Programming and Setup»(/chevrolet/avalanche/ii-2006-2013/remont/communication-devices/#programming-and-setup-all-systems__engine-control-module-programming-and-setup)
«Engine Control Module Replacement»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction__engine-control-module-replacement)

Perform the «Diagnostic System Check - Vehicle (with HP2)»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-system-check-vehicle-with) or «Diagnostic System Check - Vehicle (without HP2)»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-system-check-vehicle-without) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
Knock Sensor Signal	P0327, P0328, P0332, P0333	P0325, P0330	P0327, P0328, P0332, P0333	P0326

The knock sensor (KS) system enables the engine control module (ECM) to control the ignition timing for the best possible performance while protecting the engine from potentially damaging levels of detonation. The ECM monitors 2 separate KS, one on each side of the engine block. Each KS produces an AC voltage that varies, depending on the vibration levels detected during engine operation. The ECM receives the KS signal through 2 isolated signal circuits for each KS. The ECM adjusts the spark timing based on the amplitude and frequency of each KS signal. The ECM learns a minimum noise level for each sensor at idle speeds, and uses calibrated noise level values for the rest of the RPM range. The ECM should monitor a normal KS signal within the noise channel.

P0324

DTC P0325, P0326, P0327, P0328, P0330, P0332, or P0333 is not set.
The engine speed is greater than 300 RPM.
The engine air flow is greater than 50 mg/cylinder.
DTC P0324 runs continuously when the above conditions are met.

P0325 and P0330

DTC P0324, P0325, P0326, P0327, P0328, P0330, P0332, or P0333 is not set.
The engine speed is greater than 400 RPM.
The engine coolant temperature (ECT) is greater than -40°C (-40°F).
The engine run time is greater than 2 minutes.
DTCs P0325 and P0330 run continuously when the above conditions are met.

P0326

DTC P0068, P0120, P0121, P0122, P0123, P0220, P0222, P0223, P0606, P1516, P2101, P2135, or P2176 is not set.
The engine speed is greater than 400 RPM.
The manifold air pressure (MAP) is greater than 10 kPa.
DTC P0326 runs continuously when the above conditions are met.

P0327, P0328, P0332, and P0333

DTC P0112, P0113, P0116, P0117, P0118, or P0128 is not set.
The engine coolant temperature (ECT) is greater than -40°C (-40°F).
The engine oil temperature is less than 256°C (492.8°F).
The engine run time is greater than 2 minutes.
DTCs P0327, P0328, P0332, and P0333 run continuously when the above conditions are met.

P0324

The ECM has detected an internal circuitry fault.

P0325 or P0330

The KS signal circuits are open or shorted together for 5 seconds.

P0326

The KS signal indicates an engine knock is present.
The ECM has commanded the spark retard to a value which is more than the calibrated valve, for a specific engine load and speed.
The above conditions exist for more than 5 seconds.

P0327, P0328, P0332, and P0333

The KS signal circuits are shorted to voltage or ground.

DTCs P0324, P0325, P0326, P0327, P0328, P0330, P0332, and P0333 are Type B codes.
The ignition timing is retarded to reduce the potential of engine damaging spark knock.

DTCs P0324, P0325, P0326, P0327, P0328, P0330, P0332, and P0333 are Type B codes.

Inspect the KS for physical damage. A KS that is dropped or damaged may cause a DTC to set.
Inspect the KS for proper installation. A KS that is loose or over-torqued may cause a DTC to set.
The KS mounting surface should be free of burs, casting flash, and foreign material.

Schematic Reference

Connector End View Reference

Description and Operation

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Testing for Intermittent Conditions and Poor Connections»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-and-poor)
«Circuit Testing»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
«Wiring Repairs»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)
«Connector Repairs»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Special Tools

J 35616 GM Approved Terminal Test Kit. See Special Tools .

IMPORTANT

If DTC P0325, P0326, P0327, P0328, P0330, P0332, or P0333 are also set, diagnose those DTCs first.

DTC P0324 indicates an internal control module circuitry failure. Replace the ECM.

P0325, P0327, P0328, P0330, P0332, P0333

Ignition ON, engine OFF.
Disconnect the appropriate KS harness connector.
Measure for 2-3 volts between each of the following circuits and ground on the ECM side of the harness connector: The KS signal circuit, terminal A The KS signal circuit, terminal B If less than the specified range, test the circuits for a short to ground or an open/high resistance. If the circuits test normal, replace the ECM. If greater than the specified range, test the circuits for a short to voltage. If the circuits test normal, replace the ECM.
If all circuits test normal, replace the KS.

Inspect for a loose or broken engine mount, engine mounted accessory, or accessory mounting bracket.
Inspect for excessive engine mechanical noise. Refer to «Symptoms - Engine Mechanical»(/chevrolet/avalanche/ii-2006-2013/remont/mechanical/#engine-mechanical-48l-53l-60l-or-62l-1-of-5) .

Component Testing

Connect a DMM to both KS signal circuits, terminals A and B, at the KS.
Set the DMM to the 400 mV AC hertz scale and wait for the DMM display to stabilize at 0 Hz.
Tap on the engine block with a non-metallic object near the KS while observing the signal indicated on the DMM.
The DMM should display a fluctuating frequency while tapping on the engine block.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

«Knock Sensor 1 Replacement»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction)
«Knock Sensor 2 Replacement»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction)
«Engine Control Module Replacement»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction__engine-control-module-replacement)
«Engine Control Module Programming and Setup»(/chevrolet/avalanche/ii-2006-2013/remont/communication-devices/#programming-and-setup-all-systems__engine-control-module-programming-and-setup)

Perform the «Diagnostic System Check - Vehicle (with HP2)»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-system-check-vehicle-with) or «Diagnostic System Check - Vehicle (without HP2)»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-system-check-vehicle-without) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
5-Volt Reference Circuit	P0651	P0335	P0651, P2135
CKP Sensor Signal Circuit	P0335	P0335	P0335	P0336
Low Reference Circuit		P0335	P0335

The crankshaft position (CKP) sensor circuits consist of an engine control module (ECM) supplied 5-volt reference circuit, low reference circuit and an output signal circuit. The CKP sensor is an internally magnetic biased digital output integrated circuit sensing device. The sensor detects magnetic flux changes between the peaks and valleys of a 58-tooth reluctor wheel on the crankshaft. Each tooth on the reluctor wheel is spaced at 60-tooth spacing, with 2 missing teeth for the reference gap. The CKP sensor produces an ON/OFF DC voltage of varying frequency, with 58 output pulses per crankshaft revolution. The frequency of the CKP sensor output depends on the velocity of the crankshaft. The CKP sensor sends a digital signal, which represents an image of the crankshaft reluctor wheel, to the ECM as each tooth on the wheel rotates past the CKP sensor. The ECM uses each CKP signal pulse to determine crankshaft speed and decodes the crankshaft reluctor wheel reference gap to identify crankshaft position. This information is then used to sequence the ignition timing and fuel injection events for the engine. The ECM also uses CKP sensor output information to determine the crankshaft relative position to the camshaft, to detect cylinder misfire, and to control the CMP actuator if equipped.

DTC P0340, P0341, P0641, or P0651 is not set.
The engine is cranking or running.
DTC P0335 runs continuously when the above conditions are met.

Note. The ECM detects engine movement by sensing the airflow through the MAF sensor, when airflow is greater than 3 grams per second, or by sensing camshaft position (CMP) sensor pulses.

The ECM detects that the starter is commanded on and the engine has been cranking for more than 4 seconds without a CKP sensor pulse.
The ECM detects that the engine is running, but has not received a CKP sensor pulse for 2 of 10 engine cycles.

DTC P0335 is a Type A DTC.
The CMP actuator if equipped is commanded to the parked position.
The ignition system defaults to a limp home mode. The CMP sensor is used to determine engine position.

DTC P0335 is a Type A DTC.

With this DTC set, the engine may crank for an extended period of time during start-up.
This test procedure requires that the vehicle battery has passed a load test and is completely charged. Refer to «Battery Inspection/Test»(/chevrolet/avalanche/ii-2006-2013/remont/charging-system/#battery-charging-system-and-starting-system) .

Schematic Reference

Connector End View Reference

Description and Operation

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
«Connector Repairs»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Special Tools

J 35616-A/BT-8637: Connector Test Adapter Kit

Ignition OFF, inspect the engine wiring harness carrying the CKP sensor circuits for the following conditions: Close routing of aftermarket electrical equipment. Close to solenoids, motors, and relays. If any of these are determined to be a possible source of electrical interference, correct any wire harness routing or component placement conditions.
Start the engine. Using the live plot function on the scan tool, select the CMP sensor parameter. Change the minimum spec to 400, and the maximum spec to 4,000 RPM. Select the CKP sensor parameter. Change the minimum spec to 600, and the maximum spec to 3,300 RPM.
Observe the scan tool.
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.
Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Note. You must perform the Circuit/System Verification before proceeding with Circuit/System Testing.

Ignition OFF, disconnect the harness connector at the crankshaft position (CKP) sensor.
Test for less than 1 ohm between the CKP 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.
Ignition ON, test for 4.8-5.2 volts between the CKP 5-volt reference circuit, terminal C 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.
Ignition ON, test for 4.8-5.2 volts between the CKP signal circuit terminal A 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.
Ignition OFF, connect a fused jumper wire to the CKP signal circuit terminal A.
Ignition ON, momentarily touch the other end of the fused jumper wire to the battery negative post. The CKP Active counter, should increment. If the CKP Active counter increments, test or replace the CKP sensor. If the CKP Active counter does not increment, replace the ECM.

Note. You must perform the Circuit/System Testing before proceeding with Component Testing.

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

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

«Crankshaft Position Sensor Replacement»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction)
«Engine Control Module Programming and Setup»(/chevrolet/avalanche/ii-2006-2013/remont/communication-devices/#programming-and-setup-all-systems__engine-control-module-programming-and-setup)
«Engine Control Module Replacement»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction__engine-control-module-replacement)

Perform the «Diagnostic System Check - Vehicle (with HP2)»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-system-check-vehicle-with) or «Diagnostic System Check - Vehicle (without HP2)»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-system-check-vehicle-without) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
5-Volt Reference Circuit	P0651	P0335	P0651, P2135
CKP Sensor Signal Circuit	P0335	P0335	P0335	P0336
Low Reference Circuit		P0335	P0335

DTC P0340, P0341, P0641, or P0651 is not set.
The engine is cranking or running.
DTC P0336 runs continuously when the above conditions are met.

Note. The ECM detects engine movement by sensing the airflow through the MAF sensor, when airflow is greater than 3 grams per second, or by sensing camshaft position (CMP) sensor pulses.

The ECM detects that the engine is running, but receives less than 53 or more than 63 CKP sensor pulses, during each engine revolution, for 8 of 10 engine revolutions.
The ECM detects that the engine is running, but more than 25 crankshaft resyncs have occurred within 20 seconds.
The ECM detects that the engine has been running, but the crankshaft does not sync for 0.4 second.

DTC P0336 is a Type A DTC.
The CMP actuator if equipped is commanded to the parked position.
The ignition system defaults to a limp home mode. The CMP sensor is used to determine engine position.

DTC P0336 is a Type A DTC.

With this DTC set, the engine may crank for an extended period of time during start-up.
This test procedure requires that the vehicle battery has passed a load test and is completely charged. Refer to «Battery Inspection/Test»(/chevrolet/avalanche/ii-2006-2013/remont/charging-system/#battery-charging-system-and-starting-system) .

Schematic Reference

Connector End View Reference

Description and Operation

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
«Connector Repairs»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Special Tools

J 35616-A/BT-8637: Connector Test Adapter Kit

Ignition OFF, inspect the engine wiring harness carrying the CKP sensor circuits for the following conditions: Close routing of aftermarket electrical equipment. Close to solenoids, motors, and relays. If any of these are determined to be a possible source of electrical interference, correct any wire harness routing or component placement conditions.
Start the engine. Using the live plot function on the scan tool, select the CMP sensor parameter. Change the minimum spec to 400, and the maximum spec to 4,000 RPM. Select the CKP sensor parameter. Change the minimum spec to 600, and the maximum spec to 3,300 RPM.
Observe the scan tool.
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.
Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Note. You must perform the Circuit/System Verification before proceeding with Circuit/System Testing.

Ignition OFF, inspect the CKP sensor for looseness and correct installation. If the CKP sensor is loose, inspect the sensor and the O-ring for damage, replace as necessary.
Inspect the engine for the following conditions: Engine oil for debris and contamination Crankshaft reluctor wheel for damage The 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 cause. Repair or replace any worn or damaged components.

Note. You must perform the Circuit/System Testing before proceeding with Component Testing.

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

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

«Crankshaft Position Sensor Replacement»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction)
«Engine Control Module Programming and Setup»(/chevrolet/avalanche/ii-2006-2013/remont/communication-devices/#programming-and-setup-all-systems__engine-control-module-programming-and-setup)
«Engine Control Module Replacement»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction__engine-control-module-replacement)

Perform the «Diagnostic System Check - Vehicle (with HP2)»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-system-check-vehicle-with) or «Diagnostic System Check - Vehicle (without HP2)»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-system-check-vehicle-without) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
5-Volt Reference Circuit	P0107, P0452, P0522, P0532, P0641	P0340	P0641
CMP Sensor Signal Circuit	P0340	P0340	P0340	P0341
Low Reference Circuit		P0340	P0340

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 between the peaks and valleys 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 2 narrow, and 2 wide 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 sequence the ignition timing and fuel injection events for the engine. The ECM also uses CMP sensor output information to determine the camshaft relative position to the crankshaft, to control the CMP actuator if equipped, and for limp-home operation.

DTC P0335, P0336, P0641, or P0651 is not set.
The engine is cranking or running.
DTC P0340 runs continuously when the above conditions are met.

IMPORTANT

The ECM detects engine movement by sensing the airflow through the MAF sensor, when airflow is greater than 3 grams per second, or by sensing crankshaft position (CKP) sensor pulses.

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.
The ECM detects that the engine has started, but did not receive a CMP sensor pulse during the first engine revolution.
The ECM detects that the engine is running, but does not receive a CMP sensor pulse for 800 of 1000 engine cycles.

DTC P0340 is a Type B DTC.
The CMP actuator if equipped is commanded to the parked position.
The ignition system defaults to a failed CMP sensor limp home mode.

DTC P0340 is a Type B DTC.

With a DTC set, the engine may crank for an extended period of time during start-up.
This test procedure requires that the vehicle battery has passed a load test and is completely charged. Refer to «Battery Inspection/Test»(/chevrolet/avalanche/ii-2006-2013/remont/charging-system/#battery-charging-system-and-starting-system) .

Schematic Reference

Connector End View Reference

Description and Operation

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
«Connector Repairs»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Special Tools

J 35616-A/BT-8637 Connector Test Adapter Kit

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. If any of these are determined to be a possible source of electrical interference, correct any wire harness routing or component placement conditions.
Start the engine. Using the live plot function on the scan tool, select the CMP sensor parameter. Change the minimum spec to 400, and the maximum spec to 4,000 RPM. Select the CKP sensor parameter. Change the minimum spec to 600, and the maximum spec to 3,300 RPM.
Observe the scan tool.
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.
Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Ignition OFF, disconnect the harness connector at the camshaft position (CMP) sensor.
Test for less than 1 ohm on 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.
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.
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.
Ignition OFF, connect a fused jumper wire to the CMP signal circuit terminal C.
Ignition ON, momentarily touch the other the other end of the fused jumper wire to the battery negative post. The scan tool should show the CMP Active counter incrementing. If the CMP Active counter increments, test or replace the CMP sensor. If the CMP Active counter does not increment, replace the ECM.

IMPORTANT

You must perform the Circuit/System Testing before proceeding with Component Testing.

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.
Connect the CMP sensor harness connector to the CMP sensor.
Ignition ON, engine OFF. Observe the CMP Active counter parameter on the scan tool.
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.

«Camshaft Position Sensor Replacement (Except RPOs LY2, LC9, Ly5 and LMG)»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction) or «Camshaft Position Sensor Replacement (RPOs LY2, LC9, LY5, LMG)»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction)
«Engine Control Module Programming and Setup»(/chevrolet/avalanche/ii-2006-2013/remont/communication-devices/#programming-and-setup-all-systems__engine-control-module-programming-and-setup)
«Engine Control Module Replacement»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction__engine-control-module-replacement)

Perform the «Diagnostic System Check - Vehicle (with HP2)»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-system-check-vehicle-with) or «Diagnostic System Check - Vehicle (without HP2)»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-system-check-vehicle-without) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
5-Volt Reference Circuit	P0107, P0452, P0522, P0532, P0641	P0340	P0641
CMP Sensor Signal Circuit	P0340	P0340	P0340	P0341
Low Reference Circuit		P0340	P0340

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 between the peaks and valleys 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 two narrow, and two wide 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 sequence the ignition timing and fuel injection events for the engine. The ECM also uses CMP sensor output information to determine the camshaft relative position to the crankshaft, to control the CMP actuator if equipped, and for limp-home operation.

DTC P0335, P0336, P0641, or P0651 is not set.
The engine is cranking or running.
DTC P0341 runs continuously when the above conditions are met.

IMPORTANT

The ECM detects engine movement by sensing the airflow through the MAF sensor, when airflow is greater than 3 grams per second, or by sensing crankshaft position (CKP) sensor pulses.

The ECM detects that the engine was started, but has received less than 2 or more than 8 CMP sensor pulses during the first engine resolution.
The ECM detects that the engine has started and is running, but receives less than 398 or more than 402 CMP pulses per 100 engine cycles in 800 of 1000 engine cycles.

DTC P0341 is a Type B DTC.
The CMP actuator if equipped is commanded to the parked position.
The ignition system defaults to a failed CMP sensor limp home mode.

DTC P0341 is a Type B DTC.

With this DTC set, the engine may crank for an extended period of time during start-up.
This test procedure requires that the vehicle battery has passed a load test and is completely charged. Refer to «Battery Inspection/Test»(/chevrolet/avalanche/ii-2006-2013/remont/charging-system/#battery-charging-system-and-starting-system) .

Schematic Reference

Connector End View Reference

Description and Operation

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
«Connector Repairs»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Special Tools

J 35616-A/BT-8637 Connector Test Adapter Kit

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. If any of these are determined to be a possible source of electrical interference, correct any wire harness routing or component placement conditions.
Start the engine. Using the live plot function on the scan tool, select the CMP sensor parameter. Change the minimum spec to 400, and the maximum spec to 4,000 RPM. Select the CKP sensor parameter. Change the minimum spec to 600, and the maximum spec to 3,300 RPM.
Observe the scan tool.
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.
Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Ignition OFF, inspect the CMP sensor for looseness and correct installation. If the CMP sensor is loose, inspect the sensor and the O-ring for damage, and replace as necessary.
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 cause. Repair or replace any worn or damaged components.

IMPORTANT

You must perform the Circuit/System Testing before proceeding with Component Testing.

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.
Connect the CMP sensor harness connector to the CMP sensor.
Ignition ON, engine OFF, observe the CMP Active Counter parameter on the scan tool.
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.

«Camshaft Position Sensor Replacement (Except RPOs LY2, LC9, Ly5 and LMG)»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction) or «Camshaft Position Sensor Replacement (RPOs LY2, LC9, LY5, LMG)»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction)
«Engine Control Module Programming and Setup»(/chevrolet/avalanche/ii-2006-2013/remont/communication-devices/#programming-and-setup-all-systems__engine-control-module-programming-and-setup)
«Engine Control Module Replacement»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction__engine-control-module-replacement)

Perform the «Diagnostic System Check - Vehicle (with HP2)»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-system-check-vehicle-with) or «Diagnostic System Check - Vehicle (without HP2)»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-system-check-vehicle-without) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Circuit	Short to Ground	Open/High Resistance	Short to Voltage
Ignition Coil 1 Control Circuit	P0300, P0351	P0300, P0351	P0300, P0351
Ignition Coil 2 Control Circuit	P0300, P0352	P0300, P0352	P0300, P0352
Ignition Coil 3 Control Circuit	P0300, P0353	P0300, P0353	P0300, P0353
Ignition Coil 4 Control Circuit	P0300, P0354	P0300, P0354	P0300, P0354
Ignition Coil 5 Control Circuit	P0300, P0355	P0300, P0355	P0300, P0355
Ignition Coil 6 Control Circuit	P0300, P0356	P0300, P0356	P0300, P0356
Ignition Coil 7 Control Circuit	P0300, P0357	P0300, P0357	P0300, P0357
Ignition Coil 8 Control Circuit	P0300, P0358	P0300, P0358	P0300, P0358

The ignition system on this engine uses an individual coil/module for each cylinder. The engine control module (ECM) controls the spark event for each cylinder through the eight 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. Each ignition coil/module assembly has the following circuits

Ignition voltage
Ground
Ignition control (IC)
Low reference

If the ECM detects that the IC circuit has an incorrect voltage level, DTC P0351-P0358 will set.

The ignition is ON.
DTC P0351-P0358 runs continuously when the above condition is met.

The ECM detects one of the following failures on the IC circuit

An open
A short to ground
A short to voltage

DTCs P0351-P0358 are Type B DTCs.

This test procedure requires that the vehicle battery has passed a load test and is completely charged. Refer to «Battery Inspection/Test»(/chevrolet/avalanche/ii-2006-2013/remont/charging-system/#battery-charging-system-and-starting-system) .
A high resistance condition on any IC circuit can cause an engine misfire without setting DTC P0351-P0358.

Schematic Reference

Connector End View Reference

Description and Operation

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
«Connector Repairs»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

With the engine running, monitor the following ignition control (IC) circuit status parameters with a scan tool: Cylinder 1-8 IC Ckt. Short Gnd Test Status Cylinder 1-8 IC Ckt. Open Test Status Cylinder 1-8 IC Ckt. Short to Volts Test Status Each parameter should display OK.
With the engine running, observe the Misfire Current counters with a scan tool. The counters should not be incrementing.
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.

With the engine running, monitor the Cylinder 1-8 IC Circuit Status parameters with a scan tool. If a short to GND or Open status test displays FAULT, test for an open/high resistance or short to ground on the affected IC circuit terminal C. If a short to volts status test displays FAULT, test for a short to voltage on the affected IC circuit terminal C.
Exchange the affected ignition coil/module with the ignition coil/module of a cylinder that is not affected.
Start and run the engine. With a scan tool, monitor the IC circuit parameters and the Misfire Current counters. If the circuit status fault identified or the misfire transfers with the ignition coil/module, replace the ignition coil/module assembly. If the circuit status fault identified or the misfire does not transfer with the ignition coil/module, replace the ECM.

«Ignition Coil Replacement»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction)
«Engine Control Module Replacement»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction__engine-control-module-replacement)
«Engine Control Module Programming and Setup»(/chevrolet/avalanche/ii-2006-2013/remont/communication-devices/#programming-and-setup-all-systems__engine-control-module-programming-and-setup)

IMPORTANT

An IC circuit fault condition will result in an engine misfire, and under certain driving conditions could possibly overheat the 3-way catalytic converter.

Install any components or connectors that have been removed or replaced during diagnosis.
Perform any adjustment, programming, or setup procedures that are required when a component or module is removed or replaced.
Start and run the engine. With a scan tool, monitor the IC circuit status parameters. All IC circuit status parameters should display OK. If another DTC is present, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-trouble-code-dtc-list) and perform the appropriate diagnostic.
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 or P0430. Refer to «DTC P0420 or P0430»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-dtc-p0230-to-dtc-p0690) .

Perform the «Diagnostic System Check - Vehicle (with HP2)»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-system-check-vehicle-with) or «Diagnostic System Check - Vehicle (without HP2)»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-system-check-vehicle-without) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Note. A new converter with less than 100 miles on it may set DTC P0420 or P0430 due to out-gassing of the internal matting. Operating the vehicle at highway speeds for approximately 1 hour may correct the condition.

A 3-way catalytic converter (TWC) controls emissions by converting hydrocarbons (HC) and carbon monoxide (CO) into carbon dioxide (CO2), and oxides of nitrogen (NOx) into nitrogen. 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.

Driving Conditions DTCs P0030, P0031, P0036, P0037, P0038, P0068, P0106, P0107, P0108, P0112, P0113, P0117, P0118, P0120, P0121, P0122, P0123, P0125, P0128, P0130, P0131, P0132, P0133, P0134, P0135, P0136, P0137, P0138, P0140, P0141, P0171, P0172, P0201, P0202, P0203, P0204, P0205, P0206, P0207, P0208, P0220, P0300, P0315, P0326, P0327, P0336, P0340, P0341, P0442, P0446, P0452, P0453, P0455, P0496, P0500 (manual transmission only), P0502, P0506, P0507, P0601, P0602, P0606, P0641, P0722, P0723, P1133, P1134, P1516, P1621, P2135, P2138, P2176 are not set. The engine has been running for greater than 2 minutes. The vehicle has been driven at greater than 1,000 RPM with the mass air flow (MAF) greater than 18 g/s for greater than 30 seconds. The vehicle is in Closed Loop. The vehicle has Fuel Trim Learn enabled. The Engine Coolant Temperature (ECT) parameter is between 45-128°C (113-262°F). The Barometric Pressure (BARO) parameter is greater than 70 kPa. The Catalytic Converter Calculated Temperature parameter is greater than or equal to 420°C (788°F). The Intake Air Temperature (IAT) parameter is between -20 and +85°C (-4 and +185°F). The battery voltage is more than 11 volts.
Idle Conditions The vehicle speed is less than 3.2 km/h (2 mph). For automatic transmissions, the transmission is in Reverse, Drive, or Low. The Throttle Position (TP) parameter is less than 2 percent. The short term fuel trim (FT) is between -10 and +10 percent. This diagnostic attempts one test during each valid idle period until a pass or fail decision has been reached when the above conditions have been met. This diagnostic attempts up to 8 completed tests during each drive cycle.

The ECM has determined the catalyst efficiency has degraded below a calibrated threshold.
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.

DTCs P0420 and P0430 are Type A DTCs.

DTC Type Reference

Electrical Information Reference

Diagnostic Trouble Code (DTC) List - Vehicle

Verify that no other DTCs are set. If any DTCs are set, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-trouble-code-dtc-list) .
Operate the vehicle within the Conditions for Running the DTC while observing the scan tool TWC Mon. OFF Idle Test Conditions Met parameter. The parameter will change to Yes when the OFF Idle Conditions have been met. If not the specified value, operate the vehicle within the OFF Idle Conditions.
When the parameter has changed to Yes and the conditions are safe, stop and idle the vehicle in gear.
Apply the service brake.
Monitor the scan tool TWC Monitor Test State parameter. When the parameter indicates Active, the TWC Mon Test is running.
Continue to monitor the parameter. When the parameter indicates Inactive, the TWC Mon Test has completed.
When the test has completed, the TWC Monitor Test Count parameter will increment by one and the TWC Monitor Test Result parameter will indicate Pass, Fail, or No Decision. If no decision has been made, repeat steps 2-6 until the Test Result parameter indicates a Pass or Fail.

CAUTION

Refer to Heated Oxygen Sensor Resistance Learn Reset Caution .

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 The catalyst test may abort if the vehicle falls outside the conditions for running the DTC. A catalyst 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.
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.
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.
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 all physical conditions test normal, test or replace the catalytic converter.

«Exhaust Manifold Replacement - Left Side»(/chevrolet/avalanche/ii-2006-2013/remont/exhaust/#engine-exhaust-system)
«Exhaust Manifold Replacement - Right Side»(/chevrolet/avalanche/ii-2006-2013/remont/exhaust/#engine-exhaust-system)
«Heated Oxygen Sensor Replacement - Bank 1 Sensor 2 (2500 Series)»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction) or «Heated Oxygen Sensor Replacement - Bank 1 Sensor 2 (1500 Series)»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction)
«Heated Oxygen Sensor Replacement - Bank 2 Sensor 2 (2500 Series)»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction) or «Heated Oxygen Sensor Replacement - Bank 2 Sensor 2 (1500 Series)»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction)
«Exhaust Leakage»(/chevrolet/avalanche/ii-2006-2013/remont/exhaust/#engine-exhaust-system__exhaust-leakage)
«Restricted Exhaust»(/chevrolet/avalanche/ii-2006-2013/remont/exhaust/#engine-exhaust-system)

Verify that no other DTCs are set. If any DTCs are set, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-trouble-code-dtc-list) .
Operate the vehicle within the Conditions for Running the DTC while observing the scan tool TWC Mon. OFF Idle Test Conditions Met parameter. The parameter will change to Yes when the OFF Idle Conditions have been met. If not the specified value, operate the vehicle within the OFF Idle Conditions.
When the parameter has changed to Yes and the conditions are safe, stop and idle the vehicle in gear.
Apply the service brake.
Monitor the scan tool TWC Monitor Test State parameter. When the parameter indicates Active, the TWC Mon Test is running.
Continue to monitor the parameter. When the parameter indicates Inactive, the TWC Mon Test has completed.
When the test has completed, the TWC Monitor Test Count parameter will increment by one and the TWC Monitor Test Result parameter will indicate Pass, Fail, or No Decision. If no decision has been made, repeat steps 2-6 until the Test Result parameter indicates a Pass or Fail.

Perform the «Diagnostic System Check - Vehicle (with HP2)»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-system-check-vehicle-with) or «Diagnostic System Check - Vehicle (without HP2)»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-system-check-vehicle-without) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

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

DTCs P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0222, P0223, P0443, P0446, P0449, P0451, P0452, P0453, P0454, P0455, P0461, P0462, P0463, P0464, P0496, P0502, P0503, P0608, P0641, P0651, P1516, P2101, P2119, P2120, P2122, P2123, P2125, P2127, P2128, P2135, P2138 are not set.
The ignition 1 voltage is between 10-16 volts.
The barometric pressure (BARO) is greater than 74 kPa.
No fuel filling during the EONV test period.
The fuel level is between 15-85 percent.
The start-up engine coolant temperature (ECT) and the start-up intake air temperature (IAT) are between 0-40°C (32-104°F).
The barometric pressure (BARO) is more than 74 kPa.
The engine run time before engine shut-off was greater than 10 minutes.
The drive distance before engine shut-off was more than 5 kilometers (3.1 miles).
The ignition is OFF.
The ambient air temperature at the end of the drive cycle is between 0-32°C (32-93°F).
DTC P0442 runs once per drive cycle during the hot soak period after the ignition is turned OFF and may require up to 45 minutes to complete. The controller will not make more than 2 test attempts per day. The time since the last completed EONV test must be at least 17 hours

The ECM detects a leak in the EVAP system that is greater than a calibrated amount.
The ECM must complete several EONV tests before the diagnostic can turn the MIL on or off.

DTC P0442 is a Type A DTC.

The EVAP system can be filled with smoke more quickly and completely by opening the system opposite the end where the smoke is injected. When injecting smoke at the service port remove the fuel fill cap, or temporarily leave the vent open, until smoke is observed then close the system and continue testing. If using a fuel cap adapter at the filler neck, use the J 41413-VLV at the service port to allow the system to fill faster. See «Special Tools»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction) .
To help locate intermittent leaks using the J 41413-200 , move all EVAP components while observing smoke with the J 41413-SPT . See «Special Tools»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction) .
Individual components can be isolated and tested using adapters in the J 41413-300 .
A condition may exist where a leak in the EVAP system only exists under a vacuum condition. This type of leak may be detected by using the scan tool Purge/Seal function to create a vacuum in the EVAP system and then observe the FTP parameter for vacuum decay.

Schematic Reference

Evaporative Emissions Hose Routing Diagram

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Description and Operation

Evaporative Emission Control System Description

Scan Tool Reference

Control Module References for scan tool information

Special Tools

CH-48096 EVAP Service Access Port Tool. See «Special Tools»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction) .
J 41413-200 Evaporative Emissions System Tester (EEST). See «Special Tools»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction) .
J 41413-300 EVAP Cap and Plug Kit
J 41413-SPT High Intensity White Light. See «Special Tools»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction) .
J 41413-VLV EVAP Service Port Vent Tool. See «Special Tools»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction) .

IMPORTANT

Refer to the J 41413-200 operation manual for detailed instructions in Evaporative Emission System Diagnosis . See Special Tools . Larger volume fuel tanks and/or those with lower fuel levels may require several minutes for the floating indicator to stabilize. Ensure that the underbody temperature of the vehicle and the tester are similar.

Connect the J 41413-200 to the vehicle at the EVAP service port. See «Special Tools»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction) . 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»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction) .
Using a scan tool close the EVAP canister vent valve to seal the EVAP system.
Use the flow meter on the J 41413-200 , calibrated to 0. See «Special Tools»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction) .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 using the J 41413-SPT . See «Special Tools»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction) .

Seal the EVAP system and use the flow meter on the J 41413-200 , calibrated to 0. See «Special Tools»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction) .51 mm (0.020 in) to determine that there is no leak in the EVAP system.
Clear DTCs.

Perform the «Diagnostic System Check - Vehicle (with HP2)»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-system-check-vehicle-with) or «Diagnostic System Check - Vehicle (without HP2)»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-system-check-vehicle-without) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

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

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

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

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

The ECM detects that the commanded state of the driver and the actual state of the control circuit do not match for a minimum of 5 seconds.

DTCs P0443 and P0449 are Type B DTCs.

Schematic Reference

Evaporative Emission Control System Description

Description and Operation

Connector End View Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
«Troubleshooting with a Test Lamp»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis)
«Testing for Intermittent Conditions and Poor Connections»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

P0443

Ignition ON, engine OFF, you should hear a clicking sound when the EVAP 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.
Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

P0449

Ignition ON, engine OFF, command the EVAP vent solenoid ON and OFF with a scan tool.
Listen for a click when the valve operates. Verify that both the ON, and the OFF states are commanded.
Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Ignition OFF, disconnect the harness connector at the EVAP canister purge or vent solenoid valve.
Ignition ON, verify that a test lamp illuminates between the voltage supply circuit terminal A and ground. If the test lamp does not illuminate, test the voltage supply circuit for a short to ground or an open/high resistance. If the circuit tests normal and the voltage supply circuit fuse is open, test or replace the EVAP canister purge solenoid.
Connect a test lamp between the voltage supply circuit terminal A and the control circuit terminal B.
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 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.
If all circuits test normal, replace the appropriate solenoid valve.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

«Evaporative Emission Canister Purge Solenoid Valve Replacement»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction)
«Evaporative Emission Canister Vent Solenoid Valve Replacement (1500 Series)»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction) or «Evaporative Emission Canister Vent Solenoid Valve Replacement (2500 Series)»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction)
«Control Module References»(/chevrolet/avalanche/ii-2006-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, setup, and programming

Perform the «Diagnostic System Check - Vehicle (with HP2)»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-system-check-vehicle-with) or «Diagnostic System Check - Vehicle (without HP2)»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-system-check-vehicle-without) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Typical Scan Tool Data

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

This DTC tests the evaporative emission (EVAP) system for a restricted or blocked EVAP vent path that would cause excess amounts of vacuum to be developed in the EVAP system. With the purge valve open and the canister vent valve open, if the EVAP system vacuum goes above a calibrated threshold, the test will fail.

DTCs P0106, P0107, P0108, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0220, P0222, P0223, P0442, P0443, P0449, P0451, P0452, P0453, P0454, P0464, P0496, P0608, P0609, P0641, P0651, P1516, P2101, P2119, P2120, P2122, P2123, P2125, P2127, P2128, P2135, P2138 are not set.
The ignition voltage is between 11-18 volts.
The barometric pressure (BARO) is more than 74 kPa.
The fuel level is between 15-85 percent.
The engine coolant temperature (ECT) is less than 35°C (95°F).
The intake air temperature (IAT) is between 4-30°C (39-86°F).
DTC P0446 runs once per cold start when the above conditions are met.

The fuel tank vacuum is greater than 12 inches H2O vacuum for 5 seconds. OR
The FTP is less than -2.5 inches H2O or more than +5 inches for 60 seconds after a cold start.

DTC P0446 is a Type B DTC.

An intermittent condition could be caused by a damaged EVAP vent housing, a temporary blockage at the EVAP canister vent solenoid valve inlet, or a pinched vent hose. A blockage in the vent system will also cause a poor fuel fill condition.
An EVAP canister filter that is restricted can cause this DTC to set.

Schematic Reference

«Evaporative Emissions Hose Routing Diagram»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction)
«Engine Controls Schematics»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction)

Connector End View Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
«Testing for Intermittent Conditions and Poor Connections»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Ignition ON and fuel cap removed, verify that the FTP sensor parameter is between 1.3-1.7 volts. If not within the specified range, go to the FTP sensor section in Circuit/System Testing.
Install the fuel cap.
With the engine running, the EVAP 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 11 inches H2O. If the fuel tank vacuum is greater than the specified range, go to the restriction section in Circuit/System Testing.
Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

IMPORTANT

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

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 11 inches H2O.

If the fuel tank vacuum is greater than the specified value, isolate the restriction by disconnecting one component at a time while the EVAP canister purge solenoid valve is commanded to 100 percent and the vent valve is open.

FTP Sensor

Ignition OFF, disconnect the harness connector at the FTP sensor.
Ignition OFF, test for less than 5 ohms between the low reference circuit terminal 2 and ground. If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the FTP sensor.

«Evaporative Emission System Hoses/Pipes Replacement (2500 LWB - Intermediate)»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction) or «Evaporative Emission System Hoses/Pipes Replacement (2500 LWB - 98.4L (26 gal) Tank-Front)»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction)
«Evaporative Emission Canister Vent Solenoid Valve Replacement (1500 Series)»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction) or «Evaporative Emission Canister Vent Solenoid Valve Replacement (2500 Series)»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction)
«Evaporative Emission Canister Replacement (2500 Series)»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction) or «Evaporative Emission Canister Replacement (1500 Series)»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction)
«Evaporative Emission Hoses/Pipes Replacement - Engine»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction)
«Evaporative Emission Hose/Pipe Replacement - Chassis (1500 Series)»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction) or «Evaporative Emission Hose/Pipe Replacement - Chassis (2500 Series)»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction)
«Evaporative Emission System Cleaning»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction)
«Fuel Tank Pressure Sensor Replacement (1500 LWB - 117.3L (31 gal) Tank + E85)»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction) or «Fuel Tank Pressure Sensor Replacement (2500 Series)»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction) or «Fuel Tank Pressure Sensor Replacement (1500 Series)»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction) or «Fuel Tank Pressure Sensor Replacement (1500 SWB - 98.4L (26 gal) Tank + E85)»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction)
«Control Module References»(/chevrolet/avalanche/ii-2006-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references)

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

With the engine running, the EVAP canister vent solenoid valve open and the EVAP canister purge solenoid valve commanded to 100 percent, the fuel tank vacuum should not increase to more than 11 inches H2O.

Perform the «Diagnostic System Check - Vehicle (with HP2)»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-system-check-vehicle-with) or «Diagnostic System Check - Vehicle (without HP2)»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-system-check-vehicle-without) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Circuit	Short to Ground	High Resistance	Open	Short to Voltage	Signal Performance
FTP Sensor 5-Volt Reference	P0452, P0532, P0641	P0451	P0446, P0452	P0453, P0641
FTP Sensor Signal	P0452	P0451	P0452	P0453	P0451, P0454
FTP Sensor Low Reference		P0446, P0451	P0446		P0451

Circuit	Short to Ground	Open	Short to Voltage
Operating Conditions: Ignition ON, Engine OFF Parameter Normal Range: 1.3-1.7 V
FTP Sensor 5-Volt Reference	0 V	0 V	4.2-5 V
FTP Sensor Signal	0 V	0 V	5 V
FTP Sensor Low Reference		4.5 V

FTP Sensor Voltage

The fuel tank pressure (FTP) sensor measures air pressure or vacuum in the evaporative emission (EVAP) system. The engine control module (ECM) supplies a 5-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

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

P0452 and P0453

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

P0454

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

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 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 0.45 inch H2O in the span of 1 second.

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

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

P0451 and P0454

A restriction in the EVAP canister or vent lines could prevent fuel vapor pressure from bleeding off fast enough. If the vent system cannot bleed off pressure fast enough, the re-zero procedure may not complete successfully, which could cause this code to set.
Ensure that the reference port on the FTP sensor is unobstructed.
An FTP sensor that is skewed or does not have a linear transition from low to high may cause this code to set. Scan tool output controls, snapshot, and plot functions can help detect erratic sensor response. To test the sensor signal under vacuum conditions, use the Quick Snapshot and the Purge/Seal functions to capture data while commanding purge to 20 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»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction) .

Schematic Reference

Connector End View Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
«Connector Repairs»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Special Tools

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

Remove the fuel cap.
Ignition ON, engine OFF.
Observe the Fuel Tank Pressure Sensor parameter with a scan tool.
The FTP Sensor parameter should be 1.3-1.7 V.

Ignition OFF, disconnect the harness connector at the FTP sensor.
Ignition OFF, test for less than 5 ohms of resistance between the low reference circuit terminal 2 and ground. If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit terminal 3 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 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.
Verify the scan tool FTP sensor parameter is less than 0.2 volts. If greater than the specified range, test the signal circuit terminal 1 for a short to voltage. If the circuit tests normal, replace the ECM.
Install a 3A fused jumper wire between the signal circuit terminal 1 and the 5-volt reference circuit terminal 3. 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 ECM.
If all circuits test normal, test or replace the FTP sensor.

For DTC P0452 or P0453, always perform the «Diagnostic Repair Verification»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-repair-verification) after completing the diagnostic procedure
For DTC P0451 or P0454, clear DTCs with a scan tool
«Control Module References»(/chevrolet/avalanche/ii-2006-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, setup, and programming

Perform the «Diagnostic System Check - Vehicle (with HP2)»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-system-check-vehicle-with) or «Diagnostic System Check - Vehicle (without HP2)»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-system-check-vehicle-without) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

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

Before the ECM can report DTC P0455 failed, DTC P0496 must run and pass.
DTCs P0106, P0107, P0108, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0220, P0222, P0223, P0442, P0443, P0449, P0451, P0452, P0453, P0454, P0464, P0496, P0608, P0609, P0641, P0651, P1516, P2101, P2119, P2120, P2122, P2123, P2125, P2127, P2128, P2135, P2138 are not set.
The ignition voltage is between 11-18 volts.
The barometric pressure (BARO) is more than 74 kPa.
The fuel level is between 15-85 percent.
The engine coolant temperature (ECT) is less than 35°C (95°F).
The intake air temperature (IAT) is between 4-30°C (39-86°F).
DTC P0455 runs once per cold start when the above conditions are met.

The EVAP system is not able to achieve or maintain a calibrated level of vacuum within a set amount of time.

DTC P0455 is a Type B DTC.

Inspect for a loose, missing, damaged, or incorrect fuel fill cap.
Inspect for a damaged fuel filler neck seal surface.
A blockage or restriction in the EVAP purge solenoid valve, purge pipe, EVAP canister, or vapor pipe, can cause this DTC to set.
The EVAP system can be filled with smoke more quickly and completely by opening the system opposite the end where the smoke is injected. For example, when injecting smoke at the service port remove the fuel fill cap, or temporarily leave the vent open, until smoke is observed, then close the system and continue testing. If using a fuel cap adapter at the filler neck, use the J 41413-VLV at the service port to allow the system to fill faster. See «Special Tools»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction) .
To help locate intermittent leaks using the J 41413-200 , move all EVAP components while observing smoke with the J 41413-SPT . See «Special Tools»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction) .
Individual components can be isolated and tested using adapters in the J 41413-300 .
A condition may exist where a leak in the EVAP system only exists under a vacuum condition. This type of leak may be detected by using the scan tool Purge/Seal function to create a vacuum in the EVAP system and then observe the FTP parameter for vacuum decay.

Schematic Reference

«Evaporative Emissions Hose Routing Diagram»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction)
«Engine Controls Schematics»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction)

Connector End View Reference

Evaporative Emission Control System Description

Description and Operation

Electrical Information Reference

«Circuit Testing»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
«Connector Repairs»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/chevrolet/avalanche/ii-2006-2013/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

CH-48096 EVAP Service Access Port Tool. See «Special Tools»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction) .
GE-41415-50 Fuel Tank Cap Adapter. See «Special Tools»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction) .
J 41413-200 Evaporative Emissions System Tester (EEST). See «Special Tools»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction) .
J 41413-300 EVAP Cap and Plug Kit
J 41413-311 EVAP Plug
J 41413-SPT High Intensity White Light. See «Special Tools»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction) .
J 41413-VLV EVAP Service Port Vent Fitting. See «Special Tools»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction) .

IMPORTANT

Larger volume fuel tanks and/or those with lower fuel levels may require several minutes for the floating indicator to stabilize. Refer to the J 41413-200 operation manual for detailed instructions in Evaporative Emission System Diagnosis . See Special Tools .

Connect the J 41413-200 to the vehicle EVAP service port. See «Special Tools»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction) . 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»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction) .
Use a scan tool to seal the EVAP system.
Use the flow meter on the J 41413-200 , calibrated to 0. See «Special Tools»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction) .51 millimeter (0.020 inch) 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 using the J 41413-SPT . See «Special Tools»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction) .
To test for a restriction in the purge path, connect the J 41413-200 nitrogen/smoke hose to the J 41413-311 brass cone adapter. Disconnect the hose at the fuel cap end of the GE-41415-50 . See «Special Tools»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction) . Connect the J 41413-311 to the disconnected hose on the GE-41415-50 . See «Special Tools»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction) . Install the GE-41415-50 filler neck end only to the vehicle. See «Special Tools»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction) .
Allow the engine to idle.
Use the Purge/Seal function to seal the system with a scan tool.
Command the EVAP canister purge solenoid valve to 30 percent.
The vacuum/pressure gage on the J 41413-200 and the FTP parameter on the scan tool should both show vacuum. See «Special Tools»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction) . 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»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction) .
Verify that the vacuum increases to the abort limit on the scan tool or more than 3.2 volts, and the values are similar between the scan tool and the vacuum/pressure gage on the J 41413-200 . See «Special Tools»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction) . If the values are not similar, or the voltage did not reach 3.2 volts, replace the FTP sensor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Fuel Tank Pressure Sensor Replacement (1500 LWB - 117.3L (31 gal) Tank + E85) or Fuel Tank Pressure Sensor Replacement (2500 Series) or Fuel Tank Pressure Sensor Replacement (1500 Series) or Fuel Tank Pressure Sensor Replacement (1500 SWB - 98.4L (26 gal) Tank + E85)

Perform the «Diagnostic System Check - Vehicle (with HP2)»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-system-check-vehicle-with) or «Diagnostic System Check - Vehicle (without HP2)»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-system-check-vehicle-without) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__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 engine control module (ECM) seals the EVAP system by commanding the EVAP canister purge solenoid valve OFF and the EVAP canister vent solenoid valve ON. The ECM monitors the fuel tank pressure (FTP) sensor to determine if a vacuum is being drawn on the EVAP system. If vacuum in the EVAP system is more than a predetermined value within a predetermined time, this DTC sets.

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

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

DTCs P0106, P0107, P0108, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0220, P0222, P0223, P0442, P0443, P0446, P0449, P0451, P0452, P0453, P0454, P0464, P0608, P0609, P0641, P0651, P1516, P2101, P2119, P2120, P2122, P2123, P2125, P2127, P2128, P2135, P2138 are not set.
The ignition voltage is between 11-18 volts.
The barometric pressure (BARO) is more than 74 kPa.
The fuel level is between 15-85 percent.
The engine coolant temperature (ECT) is less than 35°C (95°F).
The intake air temperature (IAT) is between 4-30°C (39-86°F).
DTC P0496 runs once per cold start when the above conditions are met.

The ECM detects more than 10 inch H2O vacuum for 5 seconds during a non-purge condition.

DTC P0496 is a Type B DTC.

Schematic Reference

«Engine Controls Schematics»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction)
«Evaporative Emissions Hose Routing Diagram»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction)

Connector End View Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
«Testing for Intermittent Conditions and Poor Connections»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-and-poor)
«Troubleshooting with a Test Lamp»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis)
«Wiring Repairs»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Ignition ON, engine OFF, seal the EVAP system using the Purge/Seal function with a scan tool.
Start the engine.
Observe the FTP sensor with a scan tool. The Fuel Tank Pressure Sensor parameter should be less than 1.7 volts after 90 seconds. If the Fuel Tank Pressure Sensor parameter is greater than the specified range, go to Circuit/System Testing.
Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Ignition ON, engine OFF.
Seal the EVAP system using the Purge/Seal function with a scan tool.
Start the engine.
Observe the FTP sensor with a scan tool. The Fuel Tank Pressure Sensor parameter should be less than 1.7 volts after 90 seconds. If the Fuel Tank Pressure Sensor parameter is greater than the 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

Perform the «Diagnostic System Check - Vehicle (with HP2)»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-system-check-vehicle-with) or «Diagnostic System Check - Vehicle (without HP2)»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-system-check-vehicle-without) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__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.

DTCs P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0117, P0118, P0120, P0122, P0123, P0171, P0172, P0201, P0202, P0203, P0204, P0205, P0206, P0207, P0208, P0220, P0221, P0222, P0223, P0230, P0300, P0336, P0442, P0446, P0449, P0452, P0453, P0455, P0462, P0463, P0496, P1516, P2101, P2135, P2176 are not set.
The engine is operating for at least 60 seconds.
The engine is idling for greater than 10 seconds.
The engine coolant temperature (ECT) is more than -60°C (-140°F).
The intake air temperature (IAT) is more than -20°C (-4°F).
The barometric pressure (BARO) is more than 70 kPa.
The system voltage is between 9-18 volts.
The vehicle speed is less than 1.6 km/h (1 mph).
DTC P0506 and P0507 run continuously when the above conditions are met.

P0506

The actual idle speed is approximately 100 RPM lower than the desired idle speed.

P0507

The actual idle speed is approximately 200 RPM greater than the desired idle speed.

DTCs P0506 and P0507 are Type B DTCs.

A stalling condition can cause DTC P0506 to set.
An intermittent vehicle speed sensor (VSS) signal can cause DTC P0507 to set.
An intermittent clutch pedal position sensor signal, if equipped, can cause DTC P0506 to set.

Schematic Reference

Connector End View Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
«Connector Repairs»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

IMPORTANT

The engine must first be running for greater than 60 seconds, then idle at a steady state for an additional 10 seconds before comparing the actual and desired engine idle speed parameters.

Use a scan tool to compare the desired engine idle speed to the actual engine idle speed. Actual engine idle speed should be no greater than 100 RPM below desired. Actual engine idle speed should be no greater than 200 RPM above desired.
If any other DTCs are set, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-trouble-code-dtc-list) .
Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Inspect 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 Restricted exhaust Mechanical conditions that limit engine speed Repair any conditions, if necessary.
Inspect for the following conditions: Vacuum leaks A faulty positive crankcase ventilation (PCV) valve

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Perform the «Diagnostic System Check - Vehicle (with HP2)»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-system-check-vehicle-with) or «Diagnostic System Check - Vehicle (without HP2)»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-system-check-vehicle-without) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-procedure-instructions) provide 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

The ignition switch is in Run or Crank.
DTC P0601 runs continuously when the above condition is met.

P0602

The ignition switch is in Run or Crank.
DTC P0602 runs once per ignition cycle.

P0603

The ignition switch is in Run or Crank.
DTC P0603 runs once per ignition cycle.

P0604

The ignition switch is in Run or Crank.
DTC P0604 runs continuously when the above condition is met.

P0606

The ignition switch is in the Unlock/Accessory, Run, or Crank positions.
The system voltage is more than 5.23 volts.
DTC P0606 runs continuously when the above conditions are met.

P0607

The ignition switch is in Unlock, Accessory, Run or Crank.
The system voltage is more than 5.23 volts.
DTCs P0601, P0602, P0603, P0604, P0606, P062F, P0641, P0651, P2610 are not set
DTC P0607 runs continuously when the above conditions are met.

P060D

DTC P0606 is not set.
The ignition switch is in the Unlock, Accessory, Run, or Crank position.
The system voltage is more than 5.23 volts.
DTC P060D runs continuously when the above conditions are met.

P062F

The ignition is ON.
DTC P062F runs once per ignition cycle.

P2610

The ECM is powered down.
The intake air temperature is between -40 to +125°C (-40 to +257°F).
DTC P2610 runs once per ignition cycle.

The ECM detects an internal failure or incomplete programming for more than 10 seconds.

DTCs P0601, P0602, P0603, P0604, P0606, P060D, and P062F are Type A DTCs.
DTC P0607 is a Type C DTC.
DTC P2610 is a Type B DTC.

DTCs P0601, P0602, P0603, P0604, P0606, P060D, and P062F are Type A DTCs.
DTC P0607 is a Type C DTC.
DTC P2610 is a Type B DTC.

Schematic Reference

Connector End View Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
«Connector Repairs»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

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)»(/chevrolet/avalanche/ii-2006-2013/remont/communication-devices/#programming-and-setup-all-systems__service-programming-system-sps) . If DTC P0602 resets, replace the ECM.
Test the voltage and ground circuits to the ECM for the following: A short An open High resistance

If all circuits test normal, replace the ECM.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for ECM replacement, programming and setup

Perform the «Diagnostic System Check - Vehicle (with HP2)»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-system-check-vehicle-with) or «Diagnostic System Check - Vehicle (without HP2)»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-system-check-vehicle-without) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

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

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

The FPCM has detected an internal malfunction.

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

Description and Operation

Fuel System Description

Electrical Information Reference

«Circuit Testing»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
«Connector Repairs»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

IMPORTANT

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

Verify that DTCs P0602 is not set.

If the DTC is set, program the FPCM.

Verify that DTCs P0601, P0603, P0604, P0606, and P062F are not set.

If the DTCs are set, replace the FPCM.

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for FPCM replacement, setup, and programming

Perform the «Diagnostic System Check - Vehicle (with HP2)»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-system-check-vehicle-with) or «Diagnostic System Check - Vehicle (without HP2)»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-system-check-vehicle-without) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Circuit	Short to Ground	Open or High Resistance	Short to Voltage	Signal Performance
5-Volt Reference	P0641	P0641, P06A6	P0641	P06A6
Fuel Rail Pressure (FRP) Sensor Signal	P0192	P0191, P0192	P0193	P0191
Fuel Line Pressure Sensor Low Reference		P0641, P06A6		P06A6

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

The ignition is on.

The FPCM detects that the fuel pressure 5-volt reference is above or below a predetermined voltage threshold.

DTCs P0641 and P06A6 are Type A DTCs.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Description and Operation

Fuel System Description

Electrical Information Reference

«Circuit Testing»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
«Connector Repairs»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Ignition OFF, open the hood to disable the Auto-Stop function. Refer to «Hybrid Modes of Operation Description»(ref-339151-S24601963602009090300000) .
Ignition ON, verify the scan tool hood position parameter displays Open. If the hood position does not display Open, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-trouble-code-dtc-list) for DTC P254F.
Ignition OFF, disconnect harness connector of the fuel pressure sensor.
Ignition OFF, test for less than 1.0 ohm between the low reference circuit terminal 2 and ground. If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the FPCM.
Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit terminal 3 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 FPCM. If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the FPCM.
If all circuits test normal, replace the fuel pressure sensor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

«Fuel Pressure Sensor Replacement»(ref-339158-S26627361512009090300000)
«Control Module References»(/chevrolet/avalanche/ii-2006-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for FPCM replacement, setup, and programming

Diagnostic Instructions (Set in ECM)

Perform the «Diagnostic System Check - Vehicle (with HP2)»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-system-check-vehicle-with) or «Diagnostic System Check - Vehicle (without HP2)»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-system-check-vehicle-without) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-procedure-instructions) provide an overview of each diagnostic category.

Diagnostic Fault Information (Set in ECM)

Circuit	Short to Ground	Open/High Resistance	Short to Voltage
Accelerator Pedal Position (APP) Sensor 1 5-Volt Reference 2 Circuit	P0651	P2122	P0651
Accelerator Pedal Position (APP) Sensor 2 5-Volt Reference 1 Circuit	P0641	P2127	P0641
Air Conditioning (A/C) Refrigerant Pressure Sensor 5-Volt Reference 1 Circuit	P0641	P0532	P0641
Camshaft Position (CMP) Sensor 5-Volt Reference 1 Circuit	P0641	P0340	P0641
Engine Oil Pressure (EOP) Sensor 5-Volt Reference 1 Circuit	P0641	P0522	P0641
Fuel Tank Pressure (FTP) Sensor 5-Volt Reference 1 Circuit	P0641	P0452	P0641
Manifold Absolute Pressure (MAP) Sensor 5-Volt Reference 1 Circuit	P0641	P0107	P0641
The Crankshaft Position (CKP) Sensor 5-Volt Reference 2 Circuit	P0651	P0335	P0651
Throttle Position (TP) Sensor 1 and 2 5-Volt Reference 2 Circuit	P0651	P0122, P0222	P0651

Circuit/System Description (Set in ECM)

The engine control module (ECM) 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 ECM monitors the voltage on the 5-volt reference busses.

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

The manifold absolute pressure (MAP) sensor
The fuel tank pressure (FTP) sensor
The air conditioning (A/C) refrigerant pressure sensor
The accelerator pedal position (APP) sensor 2
The engine oil pressure (EOP) sensor
The camshaft position (CMP) sensor

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

The APP sensor 1
The throttle position (TP) sensor 1 and 2
The crankshaft position (CKP) sensor

Conditions for Running the DTC (Set in ECM)

The ignition is in Unlock, Accessory, Run, or Crank.
The ignition voltage is more than 5.23 volts.
DTCs P0641 and P0651 run continuously when the above conditions are met.

Conditions for Setting the DTC (Set in ECM)

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

Action Taken When the DTC Sets (Set in ECM)

DTCs P0641 and P0651 are Type A DTCs.

Conditions for Clearing the MIL/DTC (Set in ECM)

DTCs P0641 and P0651 are Type A DTCs.

Reference Information (Set in ECM)

Schematic Reference

Connector End View Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
«Connector Repairs»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification (Set in ECM)

Ignition ON, observe the scan tool 5-volt reference 1 and 2 parameters. The reading should display Circuit OK for a normally operating system.

Circuit/System Testing (Set in ECM)

IMPORTANT

Additional DTCs may set when disconnecting components.

Ignition OFF, disconnect the harness connector of all the sensors connected to the 5-volt reference bus for the applicable DTC. Refer to Circuit/System Description.
Ignition ON, test for 4.8-5.2 volts between one of the 5-volt reference circuits and ground. If less than the specified range, test all of the 5-volt reference circuits for a short to ground. If all circuits test normal, replace the ECM. If greater than the specified range, test for a short to voltage on all of the 5-volt reference circuits, or the signal circuit for each component associated with the appropriate 5-volt reference bus for a short to voltage. If all circuits test normal, replace the ECM.
Connect each component associated with the appropriate 5-volt reference bus, one at a time, while monitoring the voltage. The voltage should not change more than 1 volt. If the voltage display changes more than the specified range when a component is connected, replace the component.

Repair Procedures (Set in ECM)

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

«Accelerator Pedal Position Sensor Replacement»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction)
«Camshaft Position Sensor Replacement (Except RPOs LY2, LC9, Ly5 and LMG)»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction) or «Camshaft Position Sensor Replacement (RPOs LY2, LC9, LY5, LMG)»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction)
«Crankshaft Position Sensor Replacement»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction)
«Engine Oil Pressure Sensor and/or Switch Replacement»(/chevrolet/avalanche/ii-2006-2013/remont/mechanical/#engine-mechanical-48l-53l-60l-or-62l-2-of-5)
«Fuel Tank Pressure Sensor Replacement (1500 LWB - 117.3L (31 gal) Tank + E85)»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction) or «Fuel Tank Pressure Sensor Replacement (2500 Series)»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction) or «Fuel Tank Pressure Sensor Replacement (1500 Series)»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction) or «Fuel Tank Pressure Sensor Replacement (1500 SWB - 98.4L (26 gal) Tank + E85)»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction)
«Manifold Absolute Pressure Sensor Replacement»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction)
«Throttle Body Assembly Replacement»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction)
«Control Module References»(/chevrolet/avalanche/ii-2006-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, setup, and programming

Perform the «Diagnostic System Check - Vehicle (with HP2)»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-system-check-vehicle-with) or «Diagnostic System Check - Vehicle (without HP2)»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-system-check-vehicle-without) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-procedure-instructions) provide an overview of each diagnostic category.

Circuit	Short to Ground	Open	Short to Voltage
MIL Voltage Supply	P0650	P0650
MIL Control	P0650/MIL ON	P0650*	P0650
*The MIL Remains ON

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 engine control module (ECM) monitors the MIL control circuit for conditions that are incorrect for the commanded states of the MIL. For example, a failure condition exists if the ECM detects low voltage when the MIL is commanded OFF, or high voltage when the MIL is commanded ON.

The ignition is in the Run or Crank position.
The ignition voltage is between 9-18 volts.
The ECM has commanded the MIL ON and OFF at least once during the ignition cycle.
DTC P0650 runs continuously when the ignition is ON.

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

DTC P0650 is a Type B DTC.

If the condition is intermittent, move the related harnesses and connectors with the engine operating. Monitor the scan tool Circuit Test Status parameters for the component. The Circuit Test Status parameter will change from OK or Not Run to Fault if there is a condition with the circuit or a connection.

Schematic Reference

«Instrument Cluster Schematics»(/chevrolet/avalanche/ii-2006-2013/remont/gauges-instrument-panels/#instrument-panel-system-displays-gauges)
«Engine Controls Schematics»(/chevrolet/avalanche/ii-2006-2013/remont/testing-diagnostics/#engine-control-system-fuel-48l-53l-60l-or-62l-introduction)

Connector End View Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
«Connector Repairs»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/chevrolet/avalanche/ii-2006-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Ignition ON, command the MIL ON and OFF with a scan tool. The MIL should turn ON and OFF as commanded.
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.

If any other instrument panel cluster (IPC) indicators or gages are inoperative, refer to «Instrument Cluster Gages Inoperative»(/chevrolet/avalanche/ii-2006-2013/remont/gauges-instrument-panels/#instrument-panel-system-displays-gauges) .
Ignition OFF, disconnect ECM X1 harness connector. Ignition ON, the MIL should not illuminate. If the MIL is illuminated, test the MIL control circuit terminal X1-12 for a short to ground. If the circuit tests normal, replace the IPC.
Ignition ON, connect a 3A fused jumper wire between the MIL control circuit terminal X1-12 and ground. The MIL should illuminate. If the MIL does not illuminate, test the MIL control circuit for a short to voltage, or an open/high resistance. If the circuit tests normal, replace the IPC/bulb.
If all circuits/connections test normal, replace the ECM.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

«Instrument Cluster Replacement (Except Cadillac)»(/chevrolet/avalanche/ii-2006-2013/remont/gauges-instrument-panels/#instrument-panel-system-displays-gauges) or «Instrument Cluster Replacement (Cadillac)»(/chevrolet/avalanche/ii-2006-2013/remont/gauges-instrument-panels/#instrument-panel-system-displays-gauges)
«Control Module References»(/chevrolet/avalanche/ii-2006-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, setup, and programming

Perform the «Diagnostic System Check - Vehicle (with HP2)»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-system-check-vehicle-with) or «Diagnostic System Check - Vehicle (without HP2)»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-system-check-vehicle-without) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/avalanche/ii-2006-2013/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Circuit	Short to Ground	Open/High Resistance	Short to Voltage
Relay Coil B+	P0685	P0685
Relay Switch B+	P0689	P0689
Relay Coil Control	P0685	P0685	P0685
Relay Ignition Output Ignition 1 Voltage	P0689	P0689	P0690

Display Parameters	Normal Range	Short to Ground	Open/High Resistance	Short to Voltage
Operating Conditions: Ignition ON, engine OFF, powertrain relay commanded ON.
EC Ignition Powertrain Relay Circuit Status	OK/Incomplete	Short to GRD/Open	Short to GRD/Open	Short to B+
EC Ignition Powertrain Relay Command	ON	ON	ON	ON
EC Ignition Powertrain Relay Feedback Signal	12-12.9 V	0.0 V	0.0 V	12-12.9 V

EC Ignition Relay

The powertrain relay is a normally open relay. The relay armature is held in the open position by spring tension. Battery positive voltage is supplied directly to the relay coil and the armature contact at all times. The engine control module (ECM) supplies the ground path to the relay coil control circuit via an internal integrated circuit called an output driver module (ODM). The ODM output control is configured to operate as a low side driver for the powertrain relay. 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 the ECM, and to several additional circuits.

P0685

The ignition is ON.
The battery voltage is between 9-16 volts.

P0689

The ignition is ON.
The powertrain relay is commanded ON.
DTC P0685 is not set.

P0690

This DTC will run with the ignition ON or OFF.
This DTC will run when the powertrain relay is commanded ON or OFF.
DTC P0685 is not set.

P0685

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

P0689

The ECM detects less than 5 volts on the ignition 1 voltage circuit to the ECM.
The condition is present for more than 5 seconds.

P0690

The ECM detects more than 16 volts on the ignition 1 voltage circuit to the ECM when the relay is commanded ON.
The ECM detects more than 2 volts on the ignition 1 voltage circuit to the ECM when the relay is commanded OFF.
The condition is present for more than 2 seconds.

DTCs P0685, P0689, and P0690 are Type B DTCs.

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

Schematic Reference

Connector End View Reference