Engine Control System & Fuel System - 3.7l - DTC p0366 to DTC p2440 Chevrolet Colorado I

Diagnostic Instructions

1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Diagnostic Fault Information

DTC P0366

Circuit/System Description

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

Conditions for Running the DTC

P0366 - Near Engine Start, CMP Fast Event Based Test

1. The engine is cranking.
2. The medium resolution is less than or equal to 10 counts.

P0366 - After Engine Start, CMP Slow Event Based Test

1. The engine is running.
2. DTCs P0335, P0336, and P0365 are not set.
3. DTC P0366 runs continuously when the above conditions are met.

P0366 - Near Engine Start, CMP Fast Event Based Test

The ECM detects the incorrect number of CMP sensor pulses in 2 revolutions of the crankshaft, which is usually within 1 second.

P0366 - After Engine Start, CMP Slow Event Based Test

The ECM detects the incorrect number of CMP sensor pulses in 2,000 revolutions of the crankshaft, which is usually within 4 minutes.

Action Taken When the DTC Sets

DTC P0366 is a Type B DTC.

Conditions for Clearing the MIL/DTC

DTC P0366 is a Type B DTC.

Reference Information

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

1. With the ignition OFF, inspect the engine wiring harnesses carrying the CMP sensor circuits for the following conditions: Close routing of aftermarket electrical equipment Close to solenoids, motors, and relays Correct any wire harness routing or component placement conditions, if it is determined to be a possible source of electrical interference.
2. With the ignition ON, engine OFF, use the live plot function on the scan tool. Select the engine speed parameter and the CMP sensor parameter. Change the minimum spec to 400 RPM for both parameters. Change the maximum spec to 4,000 RPM for both parameters.
3. Start the engine and observe the scan tool.
4. Quickly accelerate and release the accelerator pedal several times. Do not accelerate past 4,000 RPM. The 2 graphed lines on the live plot display should track together across the screen.
5. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Circuit/System Testing

1. Ignition OFF, inspect the CMP sensor for correct installation. If the sensor is loose, inspect the sensor and the O-ring for damage, replace as necessary.
2. Inspect the engine for the following conditions: The engine oil for debris The camshaft 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. Refer to «Camshaft Timing Chain and Sprocket Cleaning and Inspection»(/chevrolet/colorado/i-2004-2012/remont/mechanical/#engine-mechanical-29l__camshaft-timing-chain-and-sprocket-cleaning) and «Camshafts Cleaning and Inspection»(/chevrolet/colorado/i-2004-2012/remont/mechanical/#engine-mechanical-37l) .

Component Testing

1. Inspect the CMP sensor for correct installation. Remove the CMP sensor from the engine and inspect the sensor and the O-ring for damage. If the sensor is loose, incorrectly installed, or damaged, repair or replace the CMP sensor.
2. Connect the CMP sensor connector to the CMP sensor. Turn ON the ignition, with the engine OFF.
3. Ignition ON, and engine OFF. Observe the CMP Active Counter parameter on the scan tool. Pass a steel object by the tip of the sensor repeatedly. The CMP Active Counter parameter should increment. If the parameter does not increment, replace the CMP sensor.

Repair Procedures

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Camshaft Position Sensor Replacement - Exhaust»(/chevrolet/colorado/i-2004-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-37l-introduction-2-of-2)
2. «Control Module References»(/chevrolet/colorado/i-2004-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

DTC P0411

Typical Scan Tool Data

AIR Pressure Sensor

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

The AIR diagnostic uses 3 phases to test the AIR system

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

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

During phase 2, only the AIR pump is activated. The solenoid valve is closed. Pressure sensor performance and solenoid valve deactivation are tested. Expected system pressure is 20-25 kPa above BARO.

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

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

1. DTCs P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0125, P0128, P0201, P0202, P0203, P0204, P0205, P0300, P0412, P0418, P0420, P0606, P1106, P1107, P1111, P1112, P1114, P1115, P1635, P1639, P2430, P2431, P2432, P2433 are not set.
2. More than 60 minutes has elapsed since the last cold start.
3. The system voltage is 9-18 volts.
4. The BARO parameter is more than 70 kPa.
5. The MAF sensor parameter is less than 33 g/s.
6. The AIR system is commanded ON.
7. The conditions are stable for more than 5 seconds.
8. DTC P0411 runs once per trip start up when the above conditions are met and AIR pump operation is requested.

Conditions for Setting the DTC

1. The difference between the predicted system pressure and the actual system pressure is more than 6 kPa.
2. DTC P0411 sets within 22 seconds when the above condition is met.

DTC P0411 is a Type B DTC.

DTC P0411 is a Type B DTC.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

1. If any other AIR DTCs are set, perform those diagnostics first.
2. Inspect the AIR solenoid outlet pipe for leaks.
3. Engine running, observe that the AIR Pressure Sensor parameter approximately equals BARO.
4. Engine running, enable the AIR pump with a scan tool and observe that the AIR Pressure Sensor parameter equals approximately 20-25 kPa above barometric pressure (BARO).
5. Engine running, enable the AIR system with a scan tool and observe that the AIR Pressure Sensor parameter equals approximately 8-10 kPa above BARO.
6. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

1. Inspect the AIR solenoid outlet pipe for leaks.
2. Ignition ON, observe that the AIR pump is not activated. If the AIR pump is activated, test the AIR pump voltage supply circuit for a short to voltage. If the circuit tests normal, test the AIR pump relay control circuit for a short to ground. If the circuits test normal, test the AIR pump relay. If the relay and circuits test normal, replace the ECM.
3. Ignition ON, enable the AIR pump with a scan tool and observe that the AIR pump is activated. If the AIR pump is not activated, test the AIR pump voltage supply and ground circuits for more than 2 ohms. If the circuits test normal, test both AIR pump relay voltage supply circuits for an open/high resistance or a short to ground. If the circuits test normal, test the AIR pump relay control circuit for an open/high resistance or a short to voltage. If the circuits test normal, test the AIR pump relay. If the relay and circuits test normal, test the AIR pump. If the relay, pump, and circuits test normal, replace the ECM.
4. Disconnect the AIR solenoid.
5. Connect a test lamp between the AIR solenoid voltage supply circuit terminal 6 and ground circuit terminal 4.
6. Ignition ON, observe that the test lamp is not illuminated. If the test lamp is illuminated, test the AIR solenoid valve voltage supply circuit for a short to voltage. If the circuit tests normal, test the AIR solenoid valve relay control circuit for a short to ground. If the circuits test normal, test the AIR solenoid valve relay. If the relay and circuits test normal, replace the ECM.
7. Enable the AIR solenoid with a scan tool and observe that the test lamp is illuminated. If the test lamp is not illuminated, test the AIR solenoid voltage supply circuit and both AIR solenoid relay voltage supply circuits for an open/high resistance or a short to ground. If the circuits test normal, test the AIR solenoid ground circuit for an open/high resistance. If the circuits test normal, test both AIR solenoid relay control circuits for and open/high resistance or a short to voltage. If the circuits test normal, test the AIR solenoid relay. If the relay and circuits test normal, replace the ECM.
8. Connect all electrical connectors.
9. Engine running, enable the AIR system with a scan tool and observe that the AIR Pressure Sensor parameter equals approximately 8-10 kPa above BARO. If not within the specified range, continue with this procedure.
10. Remove the AIR inlet hose from the AIR pump.
11. Engine running, enable the AIR system with a scan tool and observe that the AIR Pressure Sensor parameter increases to 8-10 kPa above BARO. If within the specified range, the AIR pump inlet hoses/pipes are restricted. Remove the restriction or replace the hose/pipe. If not within the specified range, continue with this procedure.
12. Disconnect the hose from the AIR pump outlet.
13. Disconnect the hose quick-connect from the AIR solenoid valve inlet.
14. Install a length of standard 1 inch I.D. (25.4 mm) hose from the AIR pump outlet to the AIR solenoid valve inlet.
15. Engine running, enable the AIR system with a scan tool and observe that the AIR Pressure Sensor parameter increases to 8-10 kPa above BARO. If within the specified range, the AIR pump outlet hoses/pipes are restricted or leaking. Remove the restriction or replace the hose/pipe. If less than the specified range, replace the AIR pump. If more than the specified range, continue with this procedure.
16. Remove the AIR solenoid valve.
17. Leave the standard hose and harness connector connected.
18. Engine running, enable the AIR system with a scan tool and observe that the AIR Pressure Sensor parameter increases to approximately 7 kPa above BARO. If more than the specified range, replace the AIR solenoid valve. If within the specified range, test/inspect the cylinder head for restriction.

Relay Test

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

Pump

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

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

Solenoid Valve

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

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

1. «Secondary Air Injection Check Valve Replacement»(/chevrolet/colorado/i-2004-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-37l-introduction-2-of-2)
2. «Secondary Air Injection Pump Inlet Hose Replacement»(/chevrolet/colorado/i-2004-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-37l-introduction-2-of-2)
3. «Secondary Air Injection Pump Outlet Hose Replacement»(/chevrolet/colorado/i-2004-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-37l-introduction-2-of-2)
4. «Secondary Air Injection Pump Replacement»(/chevrolet/colorado/i-2004-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-37l-introduction-2-of-2)
5. «Control Module References»(/chevrolet/colorado/i-2004-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, setup, and programming

Repair Verification

1. With the ignition ON and the engine OFF, observe that the AIR pump is not operating.
2. With the engine running, enable the AIR solenoid with a scan tool and observe that the AIR Pressure Sensor parameter equals approximately 8-10 kPa above BARO.
3. With the engine running, enable the AIR pump with a scan tool and observe that the AIR Pressure Sensor parameter equals approximately 20-25 kPa above BARO.

1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

DTC P0412 or P0418

AIR Pressure Sensor

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

The AIR diagnostic uses 3 phases to test the AIR system

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

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

During phase 2, only the AIR pump is activated. The solenoid valve is closed. Pressure sensor performance and solenoid valve deactivation are tested. Expected system pressure is 20-25 kPa above BARO.

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

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

1. The system voltage is between 9-18 volts.
2. This DTC runs on a 100 ms loop.
3. DTC P0412 and P0418 run continuously when the above conditions are met.

1. The actual and expected states of the AIR solenoid relay control circuit, DTC P0412, or the AIR pump relay control circuit, DTC P0418, do not match.
2. The condition exists for at least 2 seconds.

DTCs P0412 and P0418 are Type B DTCs.

DTCs P0412 and P0418 are Type B DTCs.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

1. Ignition ON, command the affected relay ON and OFF with a scan tool. Feel or listen to verify that the affected relay turns ON and OFF with each command.
2. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

1. Ignition OFF, disconnect the affected relay.
2. Ignition ON, connect a test lamp between the positive terminal at the battery and the relay control circuit terminal 85.
3. Command the relay ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states. If the test lamp is always ON, test the relay control circuit for a short to ground. If the circuit tests normal, replace the ECM. If the test lamp is always OFF, test the relay control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the ECM.
4. Connect an appropriately fused jumper wire between the positive voltage terminal at the battery and the load voltage supply circuit terminal 87 and verify load activation. If the load does not activate, test the load voltage supply circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the load.
5. Ignition ON, connect an appropriately fused jumper wire between the relay switch voltage supply circuit terminal 30 and the load voltage supply circuit terminal 87 and verify load activation. If the load does not activate, test the relay switch voltage supply circuit for a short to ground or an open/high resistance. If the circuit tests normal and its fuse is open, test all components connected to the fuse and replace as necessary.
6. Ignition ON, verify that a test lamp illuminates between the relay coil voltage supply circuit terminal 86 and ground. If the test lamp does not illuminate, test the relay coil voltage supply circuit for a short to ground or an open/high resistance.
7. If all circuits and the ECM test normal, test or replace the affected relay.

Relay Test

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

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

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

1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

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.

1. Driving Conditions DTCs P0030, P0036, P0107, P0108, P0112, P0113, P0117, P0118, P0122, P0123, P0125, P0128, P0130, P0131, P0132, P0133, P0134, P0135, P0136, P0137, P0138, P0140, P0141, P0171, P0172, P0201, P0202, P0203, P0204, P0205, P0220, P0300, P0315, P0326, P0327, P0336, P0340, P0341, P0442, P0443, P0446, P0449, P0452, P0453, P0455, P0496, P0506, P0507, P0601, P0602, P1133, P1516, P1621 are not set. The engine has been running for more than 10 minutes. The vehicle has been driven at more than 1,000 RPM for more than 1 minute. The vehicle is in Closed Loop. The vehicle has Fuel Trim Learn enabled. The engine coolant temperature (ECT) is between 70-125°C (156-257°F). The barometric pressure (BARO) is more than 70 kPa. The catalytic converter calculated temperature is greater than or equal to 450°C (842°F). The intake air temperature (IAT) is between -20 and +85°C (-4 and +185°F). The battery voltage is more than 11 volts.
2. 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) is 2 percent or less. The short term fuel trim (FT) is between -10 and +10 percent. This diagnostic attempts one test during each valid idle period when the above conditions have been met. This diagnostic attempts up to 6 tests during each drive cycle.

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

DTC P0420 is a Type A DTC.

DTC P0420 is a Type A DTC.

Electrical Information Reference

1. «Circuit Testing»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)
5. «Heated Oxygen Sensor Wiring Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis)

DTC Types Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

1. «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-trouble-code-dtc-list)
2. «Control Module References»(/chevrolet/colorado/i-2004-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for scan tool information.

Note. Refer to Three-Way Catalytic Converter Damage Notice

Note. Refer to Heated Oxygen Sensor Resistance Learn Reset Notice

1. If any other DTCs are set, perform those diagnostics first.
2. Inspect for the following conditions, which may cause a catalytic converter to degrade: An engine misfire High engine oil or high coolant consumption Retarded spark timing A weak or poor spark A lean fuel mixture A rich fuel mixture A damaged oxygen sensor or wiring harness 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.
3. Operate the vehicle within the Conditions for Running the DTC. If the DTC fails this key cycle, continue with this procedure.
4. Inspect the catalytic converter for the following conditions: Dents A severe discoloration caused by excessive temperatures Road damage An internal rattle caused by damaged catalyst substrate Restrictions If a condition is found, replace the catalytic converter.
5. Inspect the exhaust system for the following conditions: Leaks Physical damage Loose or missing hardware Properly torqued HO2S Restrictions If a condition is found, repair the exhaust system.
6. Inspect the post catalyst HO2S for the following conditions: A grounded wiring harness Damage If a condition is found, replace the post catalyst HO2S. If no physical condition is detected, replace the catalytic converter.

1. «Catalytic Converter Replacement (LLV/LLR - w/2WD)»(/chevrolet/colorado/i-2004-2012/remont/exhaust/#engine-exhaust-system) or «Catalytic Converter Replacement (LLV/LLR - w/4WD)»(/chevrolet/colorado/i-2004-2012/remont/exhaust/#engine-exhaust-system)
2. «Heated Oxygen Sensor 2 Replacement»(/chevrolet/colorado/i-2004-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-29l-introduction-2-of-2)
3. «Exhaust Leakage»(/chevrolet/colorado/i-2004-2012/remont/exhaust/#engine-exhaust-system__exhaust-leakage)
4. «Restricted Exhaust»(/chevrolet/colorado/i-2004-2012/remont/exhaust/#engine-exhaust-system)

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

1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provide an overview of each diagnostic category.

This diagnostic tests the evaporative emission (EVAP) system for a small leak when the key is turned OFF and the correct conditions are met. Heat from the exhaust system is transferred into a vehicle fuel tank while the vehicle is operating. When the vehicle is turned OFF and the EVAP system is sealed, a change in the fuel tank vapor temperature occurs, which results in corresponding pressure changes in the fuel tank vapor space. This change is monitored by the engine control module (ECM) using the fuel tank pressure sensor input. The ECM then makes a judgment on the integrity of the system. With a leak in the system, the amount of pressure change observed is significantly less than that of a sealed system.

1. DTCs P0106, P0107, P0108, P0112, P0113, P0117, P0118, P0121, P0122, P0128, P0443, P0446, P0449, P0452, P0453, P0455, P0462, P0463, P0496, P0502, P0601, P0602, P0606, P0641, P2610 are not set.
2. The diagnostic runs once after a cold start drive cycle.
3. The start-up intake air temperature (IAT) is between 4-30°C (39-86°F).
4. The start-up engine coolant temperature (ECT) is less than 30°C (86°F).
5. The start-up IAT and ECT are within 8°C (15°F).
6. The barometric pressure (BARO) is more than 74 kPa.
7. The ambient air temperature is between 2-32°C (36-90°F).
8. The engine run time minimum is 10 minutes.
9. The vehicle has traveled more than 5 kilometers (3 miles) this trip.
10. The ECT is more than 70°C (158°F).
11. The fuel level is between 15-85 percent.
12. The ignition is OFF.
13. A refueling event is not detected.
14. DTC P0442 runs once per drive cycle when the above conditions are met.
15. One test occurs at ignition OFF after a drive cycle, and may require up to 45 minutes to complete. No more than 2 tests per day are allowed.

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

DTC P0442 is a Type A DTC.

DTC P0442 is a Type A DTC.

Diagnostic Aids

1. 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 filler cap or temporarily leave the vent open until smoke is observed. 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.
2. To help locate intermittent leaks, use the J 41413-200 to introduce smoke into the EVAP system. Move all EVAP components while observing smoke with the J 41413-SPT .
3. To improve the visibility of the smoke exiting the EVAP system, observe the suspected leak area from different angles with the J 41413-SPT
4. A condition may exist where a leak in the EVAP system only exists under a vacuum condition. By using the scan tool Purge/Seal function to create a vacuum, seal the system and observe the FTP parameter for vacuum decay, this type of leak may be detected.
5. If a small leak is difficult to find, it may be necessary to remove the EVAP components and test them one at a time using the adapters in the J 41413-300 .

Schematic Reference

Evaporative Emissions Hose Routing Diagram

Description and Operation Reference

Evaporative Emission Control System Description

Electrical Information Reference

1. «Circuit Testing»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Special Tools

1. CH-48096 EVAP Service Access Port Tool
2. GE-41415-50 Fuel Tank Cap Adapter
3. J 41413-200 Evaporative Emission System Tester (EEST)
4. J 41413-300 EVAP Cap and Plug Kit
5. J 41413-SPT High Intensity White Light
6. J 41413-VLV EVAP Port Vent Fitting Tool

1. Connect the J 41413-200 to the vehicle service port. For vehicles without a service port, disconnect the purge tube at the quick connector on the EVAP canister side of the EVAP canister purge solenoid valve and install the CH-48096 .
2. Use a scan tool to seal the system.
3. Use the flow meter on the J 41413-200 calibrated to 0.51 mm (0.020 in) to determine that there is no leak in the EVAP system. If a leak is detected, use the J 41413-200 to apply smoke to the EVAP system at the service port or the filler neck until the leak is located.

Clear the DTCs with a scan tool.

1. Seal the system and use the flow meter on the J 41413-200 calibrated to 0.51 mm (0.020 in) to determine that there are no leaks in the EVAP system.
2. Perform the «Diagnostic Repair Verification»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-repair-verification) after completing the diagnostic procedure.

1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

DTC P0443 or 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 vent 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.

1. The ignition is ON.
2. The system voltage is between 11-18 volts.
3. 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 6 seconds.

1. DTC P0443 is a Type B DTC.
2. DTC P0449 is a Type A DTC.

1. DTC P0443 is a Type B DTC.
2. DTC P0449 is a Type A DTC.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Troubleshooting with a Test Lamp»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis)
3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

P0443

1. With the ignition ON, engine OFF, you should hear a clicking sound when the EVAP canister purge solenoid valve is commanded to 50 percent with a scan tool. The clicking sound should stop when the EVAP canister purge solenoid valve is commanded to 0 percent. The rate at which the valve cycles should increase when the commanded state is increased, and decrease when the commanded state is decreased.
2. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

P0449

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

1. Ignition OFF, disconnect the harness connector at the EVAP canister purge or vent solenoid valve.
2. 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.
3. Connect a test lamp between the voltage supply circuit terminal A and the control circuit terminal B.
4. Energize the solenoid with a scan tool. Command the EVAP canister purge solenoid valve to 50 percent with a scan tool, or the EVAP canister vent solenoid valve ON and OFF. The test lamp should respond to the command. If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the ECM. If the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the ECM.
5. If all circuits test normal, replace the appropriate solenoid valve.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Evaporative Emission Canister Purge Solenoid Valve Replacement»(/chevrolet/colorado/i-2004-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-37l-introduction-2-of-2)
2. «Evaporative Emission Canister Vent Solenoid Valve Replacement»(/chevrolet/colorado/i-2004-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-37l-introduction-2-of-2)
3. «Control Module References»(/chevrolet/colorado/i-2004-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for engine control module (ECM) replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each of the diagnostic category.

DTC P0446

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 EVAP system vacuum goes above a calibrated threshold, the test will fail.

1. DTCs P0106, P0107, P0108, P0112, P0113, P0117, P0118, P0120, P0121, P0122, P0123, P0128, P0220, P0222, P0223, P0443, P0449, P0452, P0453, P0502, P0503 are not set.
2. The ignition voltage is between 11-18 volts.
3. The barometric pressure (BARO) is more than 74 kPa.
4. The fuel level is between 15-85 percent.
5. The start-up engine coolant temperature (ECT) is less than 35°C (95°F).
6. The start-up intake air temperature (IAT) is between 4-30°C (39-86°F).
7. The start-up ECT and IAT are within 8°C (14.4°F) of each other.
8. The purge solenoid valve is enabled.
9. DTC P0446 runs once per trip when the above conditions have been met.

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

DTC P0446 is a Type B DTC.

DTC P0446 is a Type B DTC.

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

Schematic Reference

1. «Evaporative Emissions Hose Routing Diagram»(/chevrolet/colorado/i-2004-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-29l-introduction-2-of-2)
2. «Engine Controls Schematics»(/chevrolet/colorado/i-2004-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-37l-introduction-2-of-2)

Connector End View Reference

Component Connector End Views

Description and Operation

Evaporative Emission Control System Description

Electrical Information Reference

1. «Circuit Testing»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-and-poor)
3. «Wiring Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Special Tools

1. GE-41415-50 Interrupted Thread Fuel Tank Cap Adapter
2. J 41413-200 Evaporative Emissions System Tester (EEST)

1. Ignition ON and fuel cap removed, verify that the FTP sensor parameter is between 1.3-1.7 volts. If not within the specified range, go to the FTP sensor below under Circuit/System Testing.
2. Install the fuel cap.
3. With the engine running, the EVAP canister vent solenoid valve open and the EVAP canister purge solenoid valve commanded to 100 percent, the fuel tank vacuum should not increase to more than 12 inches H2O. If the fuel tank vacuum is greater than the specified range, go to the restriction below under Circuit/System Testing.
4. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Restriction

With the engine running, the EVAP canister vent solenoid valve open, and the EVAP canister purge solenoid valve commanded to 100 percent, the fuel tank vacuum should not increase to more than 12 inches H2O.

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

FTP Sensor

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

1. «Fuel Tank Pressure Sensor Replacement»(/chevrolet/colorado/i-2004-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-37l-introduction-2-of-2)
2. «Control Module References»(/chevrolet/colorado/i-2004-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for engine control module (ECM) replacement, setup, and programming

With the engine running, the EVAP canister vent solenoid valve open and the EVAP canister purge solenoid valve commanded to 100 percent, the fuel tank vacuum should not increase to more than 12 inches H2O.

1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each of the diagnostic category.

DTC P0451, P0452, P0453, or P0454

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

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

P0452 and P0453

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

P0454

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

P0451

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

P0452

The FTP sensor voltage is less than 0.1 volt for more than 10 seconds.

P0453

The FTP sensor voltage is more than 4.9 volts for more than 10 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 1 inch H2O in the span of 1 second.

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

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

P0451 and P0454

1. A restriction in the EVAP canister or vent lines could prevent fuel vapor pressure from bleeding off fast enough. If the vent system cannot bleed off pressure fast enough, the re-zero procedure may not complete successfully, which could cause this code to set.
2. Ensure that the reference port on the FTP sensor is unobstructed.
3. An FTP sensor that is skewed or does not have a linear transition from low to high may cause this code to set. Scan tool output controls, snapshot, and plot functions can help detect erratic sensor response. To test the sensor signal under vacuum conditions, use the Quick Snapshot and the Purge/Seal functions to capture data while commanding purge to 20 percent, then plot the data to look for erratic sensor operation. A similar test can be done for the pressure side of the sensor operation by applying pressure with the J 41413-200 while taking a snapshot.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Special Tools

J 41413-200 Evaporative Emission System Tester (EEST)

1. Ignition ON, observe the scan tool fuel tank pressure (FTP) sensor parameter. The reading should be between 1.3-1.7 volts with the fuel cap removed, and change with fuel tank pressure.
2. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

1. Ignition OFF, disconnect the harness connector at the FTP sensor.
2. 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.
3. 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.
4. Verify the scan tool FTP sensor parameter is less than 0.1 volt. 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.
5. 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.
6. If all circuits test normal, test or replace the FTP sensor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Fuel Tank Pressure Sensor Replacement»(/chevrolet/colorado/i-2004-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-37l-introduction-2-of-2)
2. «Control Module References»(/chevrolet/colorado/i-2004-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each of the diagnostic category.

The engine control module (ECM) tests the evaporative emission (EVAP) system for a large leak or restriction in the purge path. When the conditions for running are met, the ECM commands the EVAP canister purge solenoid valve OPEN and the EVAP vent solenoid valve CLOSED allowing engine vacuum to enter the EVAP system. The ECM monitors the fuel tank pressure (FTP) sensor signal to verify that the EVAP system is able to reach a predetermined vacuum level within a set amount of time.

1. DTCs P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0121, P0122, P0123, P0222, P0223, P0128, P0443, P0449, P0452, P0453, P0454, P0502, P0503, P0601, P0602, P0606, P0641 are not set.
2. The engine is running.
3. The ignition voltage is between 10-18 volts.
4. The barometric pressure (BARO) is more than 74 kPa.
5. The fuel level is between 15-85 percent.
6. The start-up engine coolant temperature (ECT) is between 4-30°C (39-86°F).
7. The start-up intake air temperature (IAT) is less than 30°C (86°F).
8. The start-up ECT and IAT are within 8°C (14.4°F) of each other.
9. DTC P0455 runs once per cold start within 17 minutes of start-up.

The EVAP system is not able to achieve or maintain vacuum before purge has reached a calibrated volume.

DTC P0455 is a Type B DTC.

DTC P0455 is a Type B DTC.

1. Inspect for a loose, missing, incorrect, or damaged fuel fill cap.
2. Verify that the fuel filler neck sealing surface is not distorted or damaged.
3. To help locate intermittent leaks, use the J 41413-200 to introduce smoke into the EVAP system. Move all EVAP components while observing smoke with the J 41413-SPT .
4. Reviewing the Failure Records vehicle mileage since the diagnostic test last failed may help determine how often the condition that caused the DTC to be set occurs. This may assist in diagnosing the condition.
5. A condition may exist where a leak in the EVAP system only exists under a vacuum condition. By using the scan tool Purge/Seal function to create a vacuum, seal the system and observe the FTP parameter for the vacuum decay, this type of leak may be detected.
6. If a small leak is difficult to find, it may be necessary to remove the EVAP components and leak test them one at a time using the adapters in the J 41413-300 .

Schematic Reference

1. «Evaporative Emissions Hose Routing Diagram»(/chevrolet/colorado/i-2004-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-29l-introduction-2-of-2)
2. «Engine Controls Schematics»(/chevrolet/colorado/i-2004-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-37l-introduction-2-of-2)

Connector End View Reference

Component Connector End Views

Description and Operation Reference

Evaporative Emission Control System Description

Electrical Information Reference

1. «Circuit Testing»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-and-poor)
3. «Wiring Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Special Tools

1. CH-48096 EVAP Service Access Port Tool
2. GE-41415-50 Fuel Tank Cap Adapter
3. J 41413-200 Evaporative Emission System Tester (EEST)
4. J 41413-300 EVAP Cap and Plug Kit
5. J 41413-SPT High Intensity White Light
6. J 41413-VLV EVAP Port Vent Fitting Tool

1. Connect the J 41413-200 to the vehicle service port. For vehicles without a service port, disconnect the purge tube at the quick connector on the EVAP canister side of the EVAP canister purge solenoid valve and install the CH-48096 .
2. Use a scan tool to seal the system and use the flow meter on the J 41413-200 , calibrated to 0.51 mm (0.020 in) to determine that there is no leak in the EVAP system. If a leak is detected use the J 41413-200 to apply smoke to the EVAP system at the service port or the filler neck until the leak is located.
3. Using the GE-41415-50 , connect the J 41413-200 to the fuel filler neck.
4. Start the engine.
5. Allow the engine to idle.
6. Use the Purge/Seal function to seal the system with a scan tool.
7. Command the EVAP canister purge solenoid valve to 20 percent.
8. The vacuum/pressure gage on the J 41413-200 and the FTP parameter on the scan tool should both show vacuum. 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.
9. Verify that the vacuum increases to the abort limit on the scan tool or more than 3.2 volts, and the value is similar between the scan tool and the vacuum/pressure gage on the J 41413-200 . 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.

1. «Fuel Tank Pressure Sensor Replacement»(/chevrolet/colorado/i-2004-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-37l-introduction-2-of-2)
2. «Control Module References»(/chevrolet/colorado/i-2004-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for engine ECM replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each of the diagnostic category.

DTC P0496

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.

1. DTCs P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0121, P0122, P0123, P0128, P0442, P0443, P0446, P0449, P0452, P0453, P0502, P0503, P0601, P0602, P0606, P0641 are not set.
2. The ignition voltage is between 11-18 volts.
3. The barometric pressure (BARO) is more than 74 kPa.
4. The fuel level is between 15-85 percent.
5. The start-up engine coolant temperature (ECT) is less than 35°C (95°F).
6. The start-up intake air temperature (IAT) is between 4-30°C (39-86°F).
7. The start-up ECT and IAT are within 8°C (14.4°F) of each other.
8. The vehicle speed sensor (VSS) is less than 121 km/h (75 mph).
9. DTC P0496 runs once per cold start within 17 minutes.

1. The ECM detects vacuum during a non-purge condition.
2. The fuel tank vacuum is greater than 10 inches H2O for 5 seconds within 60 seconds of cold start.

DTC P0496 is a Type B DTC.

DTC P0496 is a Type B DTC.

Schematic Reference

1. «Engine Controls Schematics»(/chevrolet/colorado/i-2004-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-37l-introduction-2-of-2)
2. «Evaporative Emissions Hose Routing Diagram»(/chevrolet/colorado/i-2004-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-29l-introduction-2-of-2)

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Troubleshooting with a Test Lamp»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis)
3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

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

1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides 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.

1. DTCs P0068, P0107, P0108, P0112, P0113, P0117, P0118, P0120, P0122, P0123, P0171, P0172, P0201, P0202, P0203, P0204, P0220, P0300, P0336, P0442, P0446, P0452, P0453, P0641, P0651, P1516, P2101, P2135, P2176 are not set.
2. The engine is operating for at least 60 seconds.
3. The engine coolant temperature (ECT) is more than 60°C (140°F).
4. The intake air temperature (IAT) is more than -20°C (-4°F).
5. The barometric pressure (BARO) is more than 70 kPa.
6. The system voltage is between 11-18 volts.
7. The vehicle speed is less than 2 km/h (1 mph).
8. The engine has been idling for greater than 10 seconds.
9. The AC mode state has not changed.
10. The power steering load state has WOT changed.
11. The transmission gear selector state has not changed.
12. DTC P0506 and P0507 run continuously when the above conditions are met.

P0506

1. The actual idle speed is approximately 100 RPM lower than the desired idle speed.
2. The above condition is present for 15 seconds.

P0507

1. The actual idle speed is approximately 200 RPM greater than the desired idle speed.
2. The above condition is present for 15 seconds.

DTCs P0506 and P0507 are Type B DTCs.

DTCs P0506 and P0507 are Type B DTCs.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

1. If there are any other DTCs set, diagnose those first.
2. Using a scan tool 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.
3. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

1. Inspect 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
2. Inspect for the following conditions: Vacuum leaks A faulty positive crankcase ventilation (PCV) valve

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each of the 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.

Conditions for Running the DTCs

P0601

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

P0602

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

P0603

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

P0604

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

P0606

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

P0607

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

P060D

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

P062F

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

P2610

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

Conditions for Setting the DTCs

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

Actions Taken When the DTC Sets

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

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

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Testing for the DTC

1. Observe the DTCs with the scan tool. If DTC P0602 is set, attempt to program the ECM before replacing the ECM. Refer to «Control Module References»(/chevrolet/colorado/i-2004-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, setup, and programming. If DTC P0602 resets, replace the ECM.
2. Test the voltage and ground inputs to the ECM for the following: A short An open High resistance

1. 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

1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each of the diagnostic category.

DTC P0641 or P0651

The engine control module (ECM) has 2 internal 5-volt reference busses called 5-volt reference 1 and 5-volt reference 2. Each reference buss provides 5-volt reference circuits for more than one sensor. A fault condition on one 5-volt reference circuit will affect the other 5-volt reference circuits connected to that reference buss. The ECM monitors the voltage on the 5-volt reference buss.

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

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

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

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

1. DTCs P0601, P0602, P0603, P0604, P0605, P0606, P0607, and P2610 are not set.
2. The ignition is in Unlock, Accessory, Run, or Crank.
3. The ignition voltage is more than 5.23 volts.
4. DTCs P0641 and P0651 run continuously when the above conditions are met.

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

DTC P0641 and P0651 are type A DTCs.

DTC P0641 and P0651 are type A DTCs.

It may be possible to locate the fault by disconnecting one component at a time from the 5-volt reference circuit while viewing the 5-Volt Reference circuit parameter on the scan tool. The scan tool parameter would change from Fault to OK when the source of the fault is disconnected.

If all 5-volt reference components have been disconnected and a Fault is still indicated, the fault may exist in the wiring harness.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

1. With the ignition ON and the engine OFF, observe the 5-volt Reference 1 and 2 parameters. The scan tool should display 4.8-5.2 volts for a normally operating system.
2. Ignition ON, observe the DTC information with a scan tool. DTCs P0641 and P0651 should not set on this ignition cycle.
3. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

1. Ignition OFF, disconnect the harness connector of all appropriate sensors for the applicable DTC.
2. Ignition ON, measure for 4.8-5.2 volts between one of the 5-volt reference circuits and ground. If the voltage is less than the specified value, test for a short to ground on all the 5-volt reference circuits. If all circuits test normal, replace the ECM. If the voltage is greater than the specified value, test for a short to voltage on all the 5-volt reference circuits. If all circuits test normal, replace the ECM.
3. Connect each component associated with the 5-volt reference circuit, one at a time, while monitoring the voltage. Verify the voltage remains between 4.8-5.2 volts. If the voltage display is not within the specified range when a component is connected, test the signal circuit for a short to voltage. If all circuits test normal, replace the component.

1. «Accelerator Pedal Position Sensor Replacement»(/chevrolet/colorado/i-2004-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-29l-introduction-2-of-2)
2. «Air Conditioning (A/C) Refrigerant Pressure Sensor Replacement (LLV, LLR)»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning)
3. «Camshaft Position Sensor Replacement - Exhaust»(/chevrolet/colorado/i-2004-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-37l-introduction-2-of-2)
4. «Evaporative Emission Canister Replacement»(/chevrolet/colorado/i-2004-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-37l-introduction-2-of-2)
5. «Fuel Tank Pressure Sensor Replacement»(/chevrolet/colorado/i-2004-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-37l-introduction-2-of-2)
6. «Manifold Absolute Pressure Sensor Replacement»(/chevrolet/colorado/i-2004-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-29l-introduction-2-of-2)
7. «Throttle Body Assembly Replacement»(/chevrolet/colorado/i-2004-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-37l-introduction-2-of-2)
8. «Secondary Air Injection Check Valve Replacement»(/chevrolet/colorado/i-2004-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-37l-introduction-2-of-2)
9. «Control Module References»(/chevrolet/colorado/i-2004-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, setup, and programming

With the ignition ON and the engine OFF, observe the 5-Volt Reference 1 and 2 parameters. The scan tool should display 4.8-5.2 volts for a normally operating system.

1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provide an overview of each diagnostic category.

DTC P0650

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.

DTC P0650 runs continuously when the ignition is ON and the ignition voltage is between 11-18 volts.

The ECM detects that the commanded state of the MIL driver and the actual state of the control circuit do not match for 6 seconds.

DTC P0650 is a type B DTC, with no MIL request.

DTC P0650 is a type B DTC, with no MIL request.

Schematic Reference

1. «Instrument Cluster Schematics»(/chevrolet/colorado/i-2004-2012/remont/gauges-instrument-panels/#instrument-panel-system-displays-gages)
2. «Engine Controls Schematics»(/chevrolet/colorado/i-2004-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-37l-introduction-2-of-2)

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

1. Ignition ON, the MIL should turn ON and OFF when commanded with a scan tool.
2. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

1. Ignition ON, verify that the IPC warning indicators are illuminated. If the IPC warning indicators are not illuminated, test the ignition circuit for a short to ground or an open/high resistance. If the circuit tests normal and the ignition circuit fuse is open, replace the IPC.
2. Ignition OFF, disconnect connector X1 at the electronic ECM.
3. Ignition ON, verify that the MIL is not illuminated. If the MIL is illuminated inspect the MIL control circuit for a short to ground. If the circuit tests normal, replace the IPC.
4. Ignition ON, verify that the MIL illuminates with a 3A fused jumper between the MIL control circuit X1-40 and ground. 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 ECM.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Instrument Cluster Replacement»(/chevrolet/colorado/i-2004-2012/remont/gauges-instrument-panels/#instrument-panel-system-displays-gages)
2. «Control Module References»(/chevrolet/colorado/i-2004-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each of the diagnostic category.

DTC P0685, P0689, or P0690

EC Ignition Relay Feedback Signal

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

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

P0685 and P0689

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

P0690

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

P0685

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

P0689

1. The ECM detects less than 10 volts on the ignition 1 voltage circuit from to the ECM.
2. The condition is present for more than 5 seconds.

P0690

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

1. DTCs P0685 and P0690 are Type B DTCs.
2. DTC P0689 is a Type C DTC.

Conditions for Clearing the DTC

1. DTCs P0685 and P0690 are Type B DTCs.
2. DTC P0689 is a Type C DTC.

1. This test procedure assumes that the vehicle battery has passed a load test and is completely charged. Refer to «Battery Inspection/Test»(/chevrolet/colorado/i-2004-2012/remont/charging-system/#battery-charging-system-and-starting-system) .
2. When disconnecting electrical connectors or removing fuses and relays from a fuse block, always inspect the component electrical terminals for corrosion and the mating electrical terminals for correct tension.

Schematic Reference

1. «Engine Controls Schematics»(/chevrolet/colorado/i-2004-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-37l-introduction-2-of-2)
2. «Power Distribution Schematics»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-introduction)

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Special Tools

J 43244 Relay Puller Pliers

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

1. With the ignition OFF, remove the powertrain relay from the underhood fuse block.
2. With the ignition ON, measure for battery positive voltage, B+, between the relay coil voltage supply circuit and ground. If the voltage measures less than B+, repair the open or high resistance in the circuit to the relay coil. All wire circuit resistance should measure less than 2 ohms.
3. Measure for voltage between the relay coil control circuit and ground. If voltage is measured on the control circuit of the relay, test for a short to voltage.
4. Connect a test lamp between the battery positive voltage supply circuit of the relay coil and the relay coil control circuit. Use a scan tool to command the powertrain relay ON and OFF. The test lamp should turn ON and OFF when toggling between the commanded states. If the test lamp stays ON all the time, test for a short to ground on the relay coil control circuit or a faulty ECM. If the test lamp stays OFF all the time, test for an open or high resistance on the relay coil control circuit or a faulty ECM. All wire circuit resistance should measure less than 2 ohms.
5. Measure for B+ between the relay armature supply circuit, and ground. If the voltage measures less than B+, repair the open or high resistance in the circuit to the relay armature. All wire circuit resistance should measure less than 2 ohms.
6. With the ignition ON, test for voltage on each test point of the ETC fuse. If voltage is present, test the ignition 1 voltage circuit between the ECM, the powertrain relay, and the ETC fuse for a short to voltage. If both circuits test normal, replace the ECM.
7. Connect a 20A fused jumper wire between the B+ terminal and the ignition 1 voltage terminal of the powertrain relay at the underhood fuse block. With a test lamp, probe both test points of the ETC fuse. If the test lamp illuminates at both test points of the ETC fuse, repair the ignition 1 voltage circuit between the powertrain relay and the ECM for an open, high resistance, or a faulty ECM. All wire circuit resistance should measure less than 2 ohms. If the test lamp only illuminates at one test point of the ETC fuse, repair the short to ground in the ignition 1 voltage circuit between the fuse and the applicable component. Replace the fuse, as necessary. If the test lamp does not illuminate on either test point of the ETC fuse, repair the open or high resistance between the powertrain relay and the ETC fuse. All wire circuit resistance should measure 2 ohms or less.
8. With a test lamp, test for voltage on both test points of the following fuses: ETC Fuse Emission 1 Fuse If the test lamp fails to illuminate on one test point of each fuse, repair the open or high resistance between the fuse and the powertrain relay. All wire circuit resistance should measure 2 ohms or less.

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

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Relay Replacement (Attached to Wire Harness)»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-introduction) or «Relay Replacement (Within an Electrical Center)»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-introduction)
2. «Control Module References»(/chevrolet/colorado/i-2004-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each of the diagnostic category.

The transmission control module (TCM) uses the controller area network (CAN) to signal the engine control module (ECM) that the TCM is requesting malfunction indicator lamp (MIL) illumination. This happens when the TCM has determined that a failure that affects emissions has occurred in transmission control system. When the ECM receives the correct message from the TCM, DTC P0700 will set.

The ignition is ON.

The TCM is requesting MIL illumination.

DTC P0700 is a Type A DTC.

DTC P0700 is a Type A DTC.

DTC P0700 can not be cleared from the ECM until the related TCM codes have been cleared.

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Refer to Diagnostic Trouble Code (DTC) List - Vehicle to correct any transmission DTCs.

1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

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

1. DTCs P0030, P0053, P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0128, P0131, P0132, P0133, P0134, P0135, P0201-P0205, P0220, P0222, P0223, P0300, P0411, P0412, P0418, P0442, P0443, P0446, P0449, P0451, P0452, P0453, P0454, P0455, P0496, P0506, P0507, P060D, P1133, P1516, P2101, P2119, P2120, P2122, P2123, P2125, P2127, P2128, P2135, P2138, P2176, P2430, P2431, P2432, P2433, P2440, P2444, P2A00 are not set.
2. The device control is not active.
3. The intrusive diagnostics are not active.
4. The engine overspeed protection is not active.
5. The traction control is not active.
6. The fuel control is in air-fuel Closed Loop.
7. The system voltage is greater than 10 volts, or less than 18 volts.
8. The engine run time is greater than 60 seconds.
9. The engine coolant temperature (ECT) is greater than -20°C (-4°F).
10. The engine speed is greater than 1,000 RPM, but less than 6,000 RPM.
11. The mass air flow is greater than 20 g/s, but less than 510 g/s.
12. This DTC runs continuously when the above conditions are met.

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

DTC P1174 is a Type B DTC.

DTC P1174 is a Type B DTC.

1. The Fuel Trim Cylinder Balance diagnostic is very sensitive to HO2S design. A non-OE sensor or an incorrect part number may set a false DTC.
2. Monitoring the misfire current counters, or misfire graph, may help to isolate the cylinder that is causing the condition.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

1. Read and record the Freeze Frame/Failure Records data taking note of the speed and load at which the DTC set.
2. Diagnose any other DTCs that are set. Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-trouble-code-dtc-list) .
3. With the engine idling and the transmission in the Park or Neutral position, observe the manifold absolute pressure (MAP) sensor parameter. The MAP sensor parameter should be between 19-42 kPa. If the MAP sensor parameter is not between 19-42 kPa, refer to «DTC P0106»(/chevrolet/colorado/i-2004-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-37l-dtc-p0013-to-dtc-p0365) .
4. Inspect the air induction system for modified, damaged, leaking, or restricted components.
5. Inspect the crankcase ventilation system for improper operation. Refer to «Crankcase Ventilation System Inspection/Description»(/chevrolet/colorado/i-2004-2012/remont/mechanical/#engine-mechanical-37l) .
6. Inspect the vacuum hoses for splits, kinks, and improper connections.
7. Inspect for vacuum leaks at the intake manifold, the throttle body, and the injector O-rings.
8. Test for a restricted, damaged, leaking, or modified exhaust system from the catalytic converter forward. Refer to «Symptoms - Engine Exhaust»(/chevrolet/colorado/i-2004-2012/remont/exhaust/#engine-exhaust-system__symptoms-engine-exhaust) .
9. Test the fuel injectors for improper operation. Refer to «Fuel Injector Diagnosis (w/CH47976)»(/chevrolet/colorado/i-2004-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-37l-diagnosis-troubleshooting) or «Fuel Injector Diagnosis (w/J39021 or w/Tech 2)»(/chevrolet/colorado/i-2004-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-37l-diagnosis-troubleshooting) .
10. Test for fuel contamination. Refer to «Alcohol/Contaminants-in-Fuel Diagnosis»(/chevrolet/colorado/i-2004-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-37l-diagnosis-troubleshooting) .
11. Test for excessive fuel in the crankcase due to leaking injectors.
12. Test the ignition system for improper operation. Refer to «Electronic Ignition (EI) System Diagnosis»(/chevrolet/colorado/i-2004-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-37l-diagnosis-troubleshooting) .
13. Test the engine for any mechanical conditions such as sticking valves, lifters, etc., which could alter the flow into the combustion chamber. Refer to «Symptoms - Engine Mechanical»(/chevrolet/colorado/i-2004-2012/remont/mechanical/#engine-mechanical-37l) .

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

1. «Air Cleaner Assembly Replacement»(/chevrolet/colorado/i-2004-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-37l-introduction-2-of-2)
2. «Air Cleaner Element Replacement»(/chevrolet/colorado/i-2004-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-37l-introduction-2-of-2)
3. «Fuel Injector Replacement»(/chevrolet/colorado/i-2004-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-37l-introduction-2-of-2__fuel-injector-replacement)
4. «Fuel System Cleaning»(/chevrolet/colorado/i-2004-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-37l-introduction-2-of-2)
5. «Fuel Tank Draining»(/chevrolet/colorado/i-2004-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-29l-introduction-2-of-2)
6. «Ignition Coil Replacement»(/chevrolet/colorado/i-2004-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-37l-introduction-2-of-2)
7. «Intake Manifold Replacement»(/chevrolet/colorado/i-2004-2012/remont/mechanical/#engine-mechanical-37l)
8. «Spark Plug Replacement»(/chevrolet/colorado/i-2004-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-37l-introduction-2-of-2)
9. «Throttle Body Assembly Replacement»(/chevrolet/colorado/i-2004-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-37l-introduction-2-of-2)

1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

System Description

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

DTC P1381 runs continuously.

1. An ABS malfunction exists for more than 10 seconds, preventing the ECM from receiving rough road detection data.
2. Engine misfire is detected and DTC P0300 set.

DTC P1381 is a Type C DTC.

DTC P1381 is a Type C DTC.

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Monitor the ABS DTCs on the scan tool.

1. If any ABS DTCs are set diagnose those first. Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-trouble-code-dtc-list) .
2. If there are no ABS DTCs set refer to «Symptoms - Antilock Brake System»(/chevrolet/colorado/i-2004-2012/remont/anti-locktraction-control/#anti-lock-brake-system-traction-control-system-stability-control-system__symptoms-antilock-brake-system) .

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

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

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

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

1. The engine is running, and a cold start has been detected.
2. The vehicle speed is less than 2 km/h (1 mph).
3. The throttle position sensor is less than 2 percent.
4. The airflow per cylinder is greater than 80 mg.
5. DTCs P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0220, P0222, P0223, P0201, P0202, P0203, P0204, P0300, P0335, P0336, P0351, P0352, P0353, P0506, P0507, P0601, P0602, P0603, P0604, P0606, P0607, P062F, P0641, P0651, P1516, P1682, P2101, P2119, P2120, P2122, P2123, P2125, P2127, P2128, P2135, P2138, P2176, P2610 are not set.

This DTC runs within 15 seconds within the first 2 minutes of start-up. This diagnostic runs once per trip when a cold start has been determined.

DTC P1400 is a Type A DTC.

DTC P1400 is a Type A DTC.

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

1. Allow the engine to cool.
2. Start and idle the engine for at least 2 minutes.
3. DTC P1400 should run and pass.
4. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

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

1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

DTC P1516, P2101, P2119, or P2176

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

1. Motor control 1
2. Motor control 2

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

P1516 and P2101

1. The ignition is ON.
2. The ignition voltage is more than 5.4 volts with engine OFF and more than 11 volts with engine running.
3. The system is not in the Battery Save mode.
4. DTC P0068 is not set.
5. DTC P1516 and P2101 run continuously when the above conditions are met.

P2119

1. The ignition is in the unlock, accessory, run, or crank position.
2. The ignition voltage is more than 8 volts.
3. The system is in the Battery Save mode.
4. DTC P2119 runs continuously when the above conditions are met.

P2176

1. The ignition is ON.
2. The system is not in the Battery Save mode.
3. DTCs P0068, P0120, P0122, P0123, P0220, P0222, P0223 are not set.
4. DTC P2176 run continuously when the above conditions are met.

P1516

The indicated throttle position does not match the predicted throttle position for more than 0.5 second.

P2101

The indicated throttle position does not match the predicted throttle position for more than 0.3 second.

P2119

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

P2176

The difference between the predicted and the actual throttle position is more than a calibrated amount for more than 1.5 seconds.

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

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

Schematic Reference

Engine Controls Schematics

Description and Operation

Throttle Actuator Control (TAC) System Description

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

1. Ignition ON, engine OFF, use a scan tool to observe the throttle position (TP) sensor 1 indicated position. Throttle position should increase as pedal is applied and decrease as pedal is released. When no accelerator pedal activity is detected, the throttle position will return to the spring loaded default position.
2. Review the Freeze Fame/Failure Records and ensure sufficient ignition voltage was present when the DTC was set. If voltage was low, verify with the owner that the battery was not discharged. If the battery has not been discharged, refer to «Power Mode Mismatch»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis) .
3. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

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

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Throttle Body Assembly Replacement»(/chevrolet/colorado/i-2004-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-37l-introduction-2-of-2)
2. «Control Module References»(/chevrolet/colorado/i-2004-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

DTC P1682

EC Ignition Relay Feedback

Ignition 1 Signal

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

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

The ignition 1 voltage of the ignition main relay is more than 2 volts different than the ignition 1 voltage of the powertrain relay for more than 2 seconds.

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

DTC P1682 is a Type A DTC.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Engine Control Module Description

Electrical Information Reference

1. «Circuit Testing»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Wiring Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

1. If DTCs P0685 or P0690 are set, diagnose those DTCs first.
2. Ignition ON, engine OFF, observe the Ignition 1 voltage signal and the EC Ignition Relay Feedback signal parameters on the scan tool. Both parameter values should display no more than 3 volts difference between the 2 parameters.
3. Ignition OFF, observe the ignition 1 voltage signal parameter on the scan tool. The parameter value should be 0 volts before the ECM powers down.

Testing the Ignition 1 Signal Circuit

1. Ignition ON, verify that B+ is available to both test points of the fuse from the powertrain relay to the ECM. If B+ is only available on one test point of the fuse, test the ignition 1 voltage circuit from the fuse to the ECM for a short to ground. If the circuit tests normal, replace the ECM. If B+ is not available on either test point of the fuse, replace the underhood fuse block.
2. Ignition OFF, disconnect the ECM C1 connector.
3. Ignition ON, verify that B+ is available at C1-19. If B+ is not available, test the ignition 1 voltage circuit for an open/high resistance conditions. If the circuit tests normal, replace the ECM.
4. If all circuits test normal, replace the ECM.

Testing the EC Ignition Relay Feedback Circuit

1. Ignition OFF, remove the powertrain relay from the underhood fuse block.
2. Ignition ON, connect a 3A fused jumper wire from B+ to the powertrain ignition 1 voltage circuit terminal. Verify that the EC Ignition Relay Feedback parameter displays B+ on the scan tool. If the scan tool parameter is less than the specified value, test the ignition 1 voltage circuit for an open/high resistance or short to ground. If the circuit tests normal, replace the ECM.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Relay Replacement (Attached to Wire Harness)»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-introduction) or «Relay Replacement (Within an Electrical Center)»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-introduction)
2. «Control Module References»(/chevrolet/colorado/i-2004-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

DTC P2120, P2122, P2123, P2125, P2127, P2128, or P2138

APP Sensor 1

APP Sensor 2

The throttle actuator control (TAC) system uses 2 accelerator pedal position (APP) sensors to monitor the accelerator pedal position. The APP sensors 1 and 2 are located within the pedal assembly. Each sensor has the following circuits

1. A 5-volt reference circuit
2. A low reference circuit
3. A signal circuit

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

P2120, P2122, P2123, P2125, P2127, P2128

1. The system voltage is more than 5.23 volts.
2. The ignition is in the Unlock/Accessory or Run position.
3. DTC P0641 is not set.
4. DTC P2120, P2122, P2123, P2125, P2127, P2128 runs continuously when the above conditions are met.

P2138

1. The system voltage is more than 5.23 volts.
2. The ignition is in the Unlock/Accessory or Run position.
3. DTC P0641, P0651, P2120, P2125 are not set.
4. DTC P2138 runs continuously when the above conditions are met.

P2120

The APP sensor 1 voltage is less than 0.32 volt, or more than 4.75 volts for more than 0.4 second.

P2122

The ECM detects that the APP sensor 1 voltage is less than 0.32 volt for more than 0.4 second.

P2123

The ECM detects that the APP sensor 1 voltage is more than 4.75 volts for more than 0.4 second.

P2125

The APP sensor 2 voltage is less than 0.32 volt, or more than 4.75 volts for more than 0.4 second.

P2127

The ECM detects that the APP sensor 2 voltage is less than 0.32 volt for more than 0.4 second.

P2128

The ECM detects that the APP sensor 2 voltage is more than 4.75 volts for more than 0.4 second.

P2138

The voltage difference between APP sensor 1 and APP sensor 2 exceeds a predetermined value for more than 2 seconds.

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

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

Schematic Reference

Engine Controls Schematics

Description and Operation

Throttle Actuator Control (TAC) System Description

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

1. Ignition ON, observe the scan tool APP sensor 1 voltage parameter. The reading should be between 0.32-4.75 volts and change with accelerator pedal input.
2. Ignition ON, observe the scan tool APP sensor 2 voltage parameter. The reading should be between 0.32-4.75 volts and change with accelerator pedal input.
3. Ignition ON, observe the scan tool APP Sensor 1 and 2 parameter. The scan tool should indicate Agree.
4. Clear the DTCs with the scan tool. Operate the vehicle within the Conditions for Running the DTC, or within the conditions that you observed from the Freeze Frame/Failure Records.
5. Verify that DTC P2120 or P2125 are not the only accelerator pedal position DTCs set. If DTC P2120 or P2125 are the only DTCs set, replace the control module.
6. Verify that DTCs P0641 or P0651 are set. If DTC P0641 or P0651 are set, refer to «DTC P0641 or P0651»(/chevrolet/colorado/i-2004-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-37l-dtc-p0366-to-dtc-p2440) .
7. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

1. Ignition ON, disconnect the accelerator pedal harness connector at the accelerator pedal. Allow sufficient time for the ECM to power down.
2. Test for less than 3 ohms of resistance between each low reference circuit terminal 4 and 5 and ground. If greater than 3 ohms, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
3. Ignition ON, test for 4.8-5.2 volts between each 5-volt reference circuit terminals 1 and 2 and ground. If less than 4.8 volts, test affected 5-volt reference circuit for an open/high resistance or short to ground. If the circuit tests normal, replace the control module. If greater than 5.2 volts, test affected 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the control module.
4. Ignition ON, verify the scan tool APP sensor 1 and 2 voltages are less than 0.1 volt. If greater than 0.1 volt, test the APP sensor 1 and 2 signal circuits terminals 3 and 6 for a short to voltage. If the circuit tests normal, replace the ECM.
5. Install a 3A fused jumper wire between the signal circuit terminal 3 and the 5-volt reference circuit terminal 2 of the APP sensor 1, and verify the APP sensor 1 voltage is greater than 4.8 volts. If less than 4.8 volts, test the APP sensor 1 signal circuit for an open, or short to ground. If the circuit tests normal, replace the control module.
6. Install a 3A fused jumper wire between the signal circuit terminal 6 and the 5-volt reference circuit terminal 5 of the APP sensor 2, and verify that the APP sensor 2 voltage is greater than 4.8 volts. If less than 4.8 volts, test the APP sensor 2 signal circuit for an open/high resistance, or short to ground. If the circuit tests normal, replace the control module.
7. Ignition OFF, disconnect the harness connector at the ECM.
8. Test for less than 5 ohms of resistance on all APP sensor circuits between the following terminals: The signal circuit terminal 3 to the corresponding ECM terminal The signal circuit terminal 6 to the corresponding ECM terminal The 5-volt reference circuit terminal 1 to the corresponding ECM terminal The 5-volt reference circuit terminal 2 to the corresponding ECM terminal If greater than 5 ohms, repair the affected circuit.
9. Test for infinite resistance between APP sensor 1 signal circuit terminal 3 and APP sensor 2 signal circuit terminal 6. If less than infinite resistance, repair the short between APP sensor 1 signal circuit and APP sensor 2 signal circuit. If all circuits test normal, replace the accelerator pedal.

Dynamic Test

1. Install a 3A fused jumper wire between the 5-volt reference terminal of the applicable APP sensor and 5 volts. Install a jumper wire between the low reference terminal and a ground.
2. Sweep the sensor through the entire range while monitoring the voltage between the signal terminal and the low reference terminal with a DMM. The voltage should vary between 0.32-4.75 volts without any spikes or dropouts. If the voltage is not within the specified range or is erratic, replace the accelerator pedal assembly.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Accelerator Pedal Position Sensor Replacement»(/chevrolet/colorado/i-2004-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-29l-introduction-2-of-2)
2. «Control Module References»(/chevrolet/colorado/i-2004-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

DTC P2430, P2431, P2432, or P2433

AIR Pressure Sensor

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

The AIR diagnostic uses 3 phases to test the AIR system

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

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

During phase 2, only the AIR pump is activated. The solenoid valve is closed. Pressure sensor performance and solenoid valve deactivation are tested. Expected system pressure is 20-25 kPa above BARO.

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

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

P2430

1. DTCs P0412, P0418, P0606, P1635, P1639, P2432, P2433 are not set.
2. More than 60 minutes has elapsed since the last cold start.
3. The AIR pump is commanded ON.
4. DTC P2430 runs continuously when the above conditions are met.

P2431

1. DTCs P0106, P0107, P0108, P0412, P0418, P0606, P1635, P1639, P2432, P2433 are not set.
2. The ignition is ON.
3. DTC P2431 runs continuously when the above conditions are met.

P2432 and P2433

1. DTCs P0606, P1635, P1639 are not set.
2. The ignition is ON or the engine is running.
3. DTC P2432 and 2433 run continuously when the above conditions are met.

P2430

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

P2431

1. The ECM determines that the difference between the AIR pressure sensor and the BARO sensor signals is greater than 10 kPa when the AIR pump is commanded OFF. OR
2. The ECM determines that the difference between the AIR pressure sensor and the BARO sensor signals is greater than 50 kPa when the AIR pump is commanded ON.

P2432

The pressure sensor signal is less than 0.2 volt for at least 12.5 seconds.

P2433

The pressure sensor signal is more than 4.8 volts for at least 12.5 seconds.

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

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

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

1. Ignition ON, verify that the AIR pump is not activated.
2. Ignition ON, observe that the AIR Pressure Sensor parameter approximately equals the BARO parameter. If not equal, verify that the BARO parameter reading is correct for your altitude. Refer to «Altitude Versus Barometric Pressure»(/chevrolet/colorado/i-2004-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-29l-introduction-2-of-2__altitude-versus-barometric-pressure) . If the reading is not correct for your altitude, diagnose the manifold absolute pressure (MAP) sensor. Refer to «DTC P0106»(/chevrolet/colorado/i-2004-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-37l-dtc-p0013-to-dtc-p0365) . If the BARO parameter is correct for your altitude, proceed with Circuit/System Testing.
3. Engine running, enable the AIR system with a scan tool and observe that the AIR Pressure Sensor parameter equals approximately 8-10 kPa above BARO. If less than the specified range, verify that the AIR pump is activating. If AIR pump activation is normal, proceed with Circuit/System Testing.
4. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

1. Ignition OFF, disconnect the harness connector at the AIR solenoid valve.
2. Ignition OFF, test for less than 1 ohm between the low reference circuit terminal 1 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.
3. 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.
4. Verify the scan tool AIR Pressure Sensor parameter is less than 0.5 volt. If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the ECM.
5. Install a 3A fused jumper wire between the signal circuit terminal 2 and the 5-volt reference circuit terminal 3. Verify the scan tool AIR Pressure Sensor parameter is greater than 4.9 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.
6. Connect all electrical connectors.
7. Ignition ON, engine OFF, observe the AIR Pressure Sensor parameter. If the AIR Pressure Sensor parameter does not equal the BARO parameter, replace the AIR solenoid valve.
8. Engine running, enable the AIR system with a scan tool and observe that the AIR Pressure Sensor parameter equals approximately 8-10 kPa above BARO. If not within the specified range, continue with this procedure.
9. Remove the AIR inlet hose from the AIR pump.
10. Engine running, enable the AIR system with a scan tool and observe that the AIR Pressure Sensor parameter increases to 8-10 kPa above BARO. If within the specified range, the AIR pump inlet hoses/pipes are restricted. Remove the restriction or replace the hose/pipe. If not within the specified range, continue with this procedure.
11. Disconnect the hose from the AIR pump outlet.
12. Disconnect the hose quick-connect from the AIR solenoid valve inlet.
13. Install a length of standard 25.4 mm (1 inch I.D.) hose from the AIR pump outlet to the AIR solenoid valve inlet.
14. Engine running, enable the AIR system with a scan tool and observe that the AIR Pressure Sensor parameter increases to 8-10 kPa above BARO. If within the specified range, the AIR pump outlet hoses/pipes are restricted or leaking. Remove the restriction or replace the hose/pipe. If less than the specified range, replace the AIR pump. If more than the specified range, continue with this procedure.
15. Remove the AIR solenoid valve.
16. Leave the standard hose and harness connector connected.
17. Engine running, enable the AIR system with a scan tool and observe that the AIR Pressure Sensor parameter increases to approximately 7 kPa above BARO. If more than the specified range, replace the AIR solenoid valve. If within the specified range, test/inspect the cylinder head for restriction.

Solenoid

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

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

1. «Secondary Air Injection Pump Replacement»(/chevrolet/colorado/i-2004-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-37l-introduction-2-of-2)
2. «Secondary Air Injection Check Valve Replacement»(/chevrolet/colorado/i-2004-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-37l-introduction-2-of-2)
3. «Secondary Air Injection Pump Inlet Hose Replacement»(/chevrolet/colorado/i-2004-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-37l-introduction-2-of-2)
4. «Secondary Air Injection Pump Outlet Hose Replacement»(/chevrolet/colorado/i-2004-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-37l-introduction-2-of-2)
5. «Control Module References»(/chevrolet/colorado/i-2004-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for control module replacement, setup, and programming

1. Engine running, observe that the AIR Pressure Sensor parameter approximately equals BARO.
2. Engine running, enable the AIR pump with a scan tool and observe that the AIR Pressure Sensor parameter equals approximately 20-25 kPa above BARO.
3. Engine running, enable the AIR solenoid with a scan tool and observe that the AIR Pressure Sensor parameter equals approximately 8-10 kPa above BARO.

1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

DTC P2440

AIR Pressure Sensor

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

The AIR diagnostic uses 3 phases to test the AIR system

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

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

During phase 2, only the AIR pump is activated. The solenoid valve is closed. Pressure sensor performance and solenoid valve deactivation are tested. Expected system pressure is 20-25 kPa above BARO.

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

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

1. DTCs P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0125, P0128, P0201, P0202, P0203, P0204, P0205, P0300, P0412, P0418, P0420, P0606, P1106, P1107, P1111, P1112, P1114, P1115, P1635, P1639, P2430, P2431, P2432, P2433 are not set.
2. More than 60 minutes has elapsed since the last cold start.
3. The system voltage is 9-18 volts.
4. The BARO parameter is more than 70 kPa.
5. The MAF sensor parameter is less than 33 g/s.
6. The AIR system is commanded ON.
7. The conditions are stable for more than 5 seconds.
8. DTC P2440 runs once per trip start up when the above conditions are met and AIR pump operation is requested.

1. The AIR system does not meet expected pressure conditions.
2. DTC P2440 sets with in 8 seconds when the above conditions are met.

DTC P2440 is a Type B DTC.

DTC P2440 is a Type B DTC.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

1. If any secondary air injection system pressure sensor circuit DTCs are set, perform those diagnostics first.
2. Inspect the AIR hoses/pipes between the pump and the shut-off valve for leaks.
3. Engine running, enable the AIR pump and observe that the AIR Pressure Sensor parameter increases to approximately 20-25 kPa above BARO.
4. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the freeze Frame/Failure Records data.

1. Disconnect the solenoid valve.
2. Ignition ON, observe that a test lamp installed between the solenoid voltage supply circuit terminal 6 and the solenoid ground circuit terminal 4 is not illuminated. If the test lamp is illuminated, test for a short to voltage on the solenoid voltage supply circuit. If the circuit tests normal, test or replace the relay.
3. Inspect the AIR pump inlet and outlet hoses/pipes for restrictions.
4. Inspect the solenoid valve for leaks.
5. If the solenoid valve inspects OK, replace the AIR pump.

Relay Test

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

1. «Secondary Air Injection Check Valve Replacement»(/chevrolet/colorado/i-2004-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-37l-introduction-2-of-2)
2. «Secondary Air Injection Pump Inlet Hose Replacement»(/chevrolet/colorado/i-2004-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-37l-introduction-2-of-2)
3. «Secondary Air Injection Pump Outlet Hose Replacement»(/chevrolet/colorado/i-2004-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-37l-introduction-2-of-2)
4. «Secondary Air Injection Pump Replacement»(/chevrolet/colorado/i-2004-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-37l-introduction-2-of-2)
5. «Control Module References»(/chevrolet/colorado/i-2004-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, setup, and programming

With the engine running, enable the AIR pump and observe that the AIR Pressure Sensor parameter increases to approximately 20-25 kPa above BARO.

1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/chevrolet/colorado/i-2004-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

DTC P2444

AIR Pressure Sensor

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

The AIR diagnostic uses 3 phases to test the AIR system

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

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

During phase 2, only the AIR pump is activated. The solenoid valve is closed. Pressure sensor performance and solenoid valve deactivation are tested. Expected system pressure is 20-25 kPa above BARO.

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

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

1. DTCs P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0125, P0128, P0201, P0202, P0203, P0204, P0205, P0300, P0412, P0418, P0420, P0606, P1106, P1107, P1111, P1112, P1114, P1115, P1635, P1639, P2430, P2431, P2432, P2433 are not set.
2. More than 60 minutes has elapsed since the last cold start.
3. The system voltage is 9-18 volts.
4. The BARO parameter is more than 70 kPa.
5. The MAF sensor parameter is less than 33 g/s.
6. The AIR system is commanded ON.
7. The conditions are stable for more than 5 seconds.
8. DTC P2444 runs once per trip start up when the above conditions are met and AIR pump operation is requested.

1. The measured AIR pressure is more than expected.
2. DTC P2444 sets within 5 seconds when the above condition is met.

DTC P2444 is a Type A DTC.

DTC P2444 is a Type A DTC.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

1. If DTCs P0411, P0418, P2432 or P2433 are set, perform those diagnostics first.
2. Ignition ON, observe that the AIR pump is not activated. If the AIR pump is activated, test the AIR pump voltage supply circuit for a short to voltage. If the circuit tests normal, test the AIR pump relay control circuit for a short to ground. If the circuits test normal, test the relay. If the circuits and relay test normal, replace the ECM.
3. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Feeeze Frame/Failure Records data.

Relay Test

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

1. «Secondary Air Injection Pump Replacement»(/chevrolet/colorado/i-2004-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-37l-introduction-2-of-2)
2. «Secondary Air Injection Check Valve Replacement»(/chevrolet/colorado/i-2004-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-37l-introduction-2-of-2)
3. «Secondary Air Injection Pump Inlet Hose Replacement»(/chevrolet/colorado/i-2004-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-37l-introduction-2-of-2)
4. «Secondary Air Injection Pump Outlet Hose Replacement»(/chevrolet/colorado/i-2004-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-37l-introduction-2-of-2)
5. «Control Module References»(/chevrolet/colorado/i-2004-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for control module replacement, setup, and programming

With the ignition ON and the engine OFF, observe that the AIR pump is not operating.

See also:
• Diagnostic System Check - Vehicle
• Strategy Based Diagnosis
• Diagnostic Procedure Instructions
• Engine Controls Schematics
• Component Connector End Views
• Circuit Testing
• Connector Repairs
• Testing for Intermittent Conditions and Poor Connections
• Wiring Repairs
• Powertrain Diagnostic Trouble Code (DTC) Type Definitions
• Control Module References
• Camshaft Timing Chain and Sprocket Cleaning and Inspection
• Camshafts Cleaning and Inspection
• Diagnostic Repair Verification
• Heated Oxygen Sensor Wiring Repairs
• Diagnostic Trouble Code (DTC) List - Vehicle
• Three-Way Catalytic Converter Damage Notice
• Heated Oxygen Sensor Resistance Learn Reset Notice
• Catalytic Converter Replacement (LLV/LLR - w/2WD)
• Heated Oxygen Sensor 2 Replacement
• Exhaust Leakage
• Evaporative Emission System Diagnosis
• Air Conditioning (A/C) Refrigerant Pressure Sensor Replacement (LLV, LLR)
• Instrument Cluster Schematics
• Battery Inspection/Test
• Power Distribution Schematics
• DTC P0106
• Symptoms - Engine Exhaust
• Fuel Injector Diagnosis (w/CH47976)
• Fuel Injector Replacement
• Symptoms - Antilock Brake System
• Engine Control Module Description
• Altitude Versus Barometric Pressure
• DTC P0641 or P0651