Cobalt 2006-2008, G5 2007

2.4L L4 VIN B Std 4

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Trouble Code: P0328



Knock Sensor (KS) Circuit High Voltage

Possible Causes:



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

Trouble Code: P0335



Crankshaft Position (CKP) Sensor Circuit

Possible Causes:



When the ECM enables starter operation, the ECM also initiates the diagnostic test routines for the CKP and camshaft position (CMP) sensors. If the ignition switch is in the start position for more than 4 seconds without the engine cranking, the CKP diagnostics may fail and set this DTC.
 
Insufficient fuel may cause this DTC to set.
 

Trouble Code: P0335



Crankshaft Position (CKP) Sensor Circuit

Trouble Code: P0335



Crankshaft Position Sensor Circuit Malfunction

Possible Causes:



CKP sensor signal (+) circuit or (-) circuit is open or shorted to ground
 
CKP sensor is damaged or has failed
 
ECM has failed
 

Trouble Code: P0336



Crankshaft Position (CKP) Sensor Performance

Trouble Code: P0336



Crankshaft Reference 18X Circuit Malfunction

Possible Causes:



CKP sensor signal circuit is open or shorted to ground
 
CKP sensor VREF circuit is open, or the ground (Low Reference) circuit is open
 
CKP sensor is damaged or it failed (check the crankshaft reluctor)
 
CKP sensor wiring routed close to spark plug wires (EMI/RFI)
 
ECM has failed
 

Trouble Code: P0340



Intake CMP Sensor Circuit

Trouble Code: P0340



CMP Sensor Circuit Malfunction

Possible Causes:



CMP sensor signal circuit is open, shorted to ground or shorted to VREF between the sensor and the ECM
 
CMP sensor VREF circuit is open between sensor and ECM
 
CMP sensor ground circuit or "shielded" ground circuit is open
 
CMP sensor is cracked or damaged (check the reluctor wheel)
 
ECM has failed
 

Trouble Code: P0341



Intake Camshaft Position (CMP) Sensor Performance

Trouble Code: P0341



CMP Sensor Signal Range/Performance

Possible Causes:



CMP sensor signal circuit is open, shorted to ground or VREF
 
CMP sensor signal wire is routed to close to the Generator, spark plug wires or any other possible cause of EMI/RFI under the hood (check for high power receivers causing interference)
 
CMP sensor "shield" ground circuit is open (intermittent fault)
 
CMP sensor is cracked or damaged (check the reluctor wheel)
 
ECM has failed
 

Trouble Code: P0351



Ignition Coil 1 Control Circuit

Trouble Code: P0351



Ignition Coil 1 Control Circuit Malfunction

Possible Causes:



IC circuit is open, shorted to ground or shorted to power
 
Ignition coil (COP) is damaged or has failed
 
ECM has failed
 

Trouble Code: P0352



Ignition Coil 2 Control Circuit

Trouble Code: P0352



Ignition Coil 2 Control Circuit Malfunction

Possible Causes:



IC circuit is open, shorted to ground or shorted to power
 
Ignition coil (COP) is damaged or has failed
 
ECM has failed
 

Trouble Code: P0353



Ignition Coil 3 Control Circuit

Trouble Code: P0353



Ignition Coil 3 Control Circuit Malfunction

Possible Causes:



IC circuit is open, shorted to ground or shorted to power between the coil and the ECM
 
Ignition coil (COP) is damaged or has failed
 
ECM has failed
 

Trouble Code: P0354



Ignition Coil 4 Control Circuit

Trouble Code: P0354



Ignition Coil 4 Control Circuit Malfunction

Possible Causes:



IC circuit is open, shorted to ground or shorted to power between the coil and the ECM
 
Ignition coil (COP) is damaged or has failed, or the ECM has failed
 

Trouble Code: P0365



Exhaust Camshaft Position (CMP) Sensor Circuit

Trouble Code: P0365



Exhaust Camshaft Position (CMP) Sensor Performance

Possible Causes:



Camshaft reluctor wheel for damage
 
Engine oil for debris
 
Timing chain, tensioner, and sprockets for wear or damage.
 
CMP has failed
 
ECM has failed
 

Trouble Code: P0366



Exhaust Camshaft Position (CMP) Sensor Performance

Trouble Code: P0366



Exhaust Camshaft Position (CMP) Sensor Performance (Bank 1)

Possible Causes:



Low reference circuit for an open/high resistance or for a short to voltage
 
5 volt reference circuit for an open/high resistance
 
Short to voltage in the signal circuit
 
Short to ground or an open/high resistance in the signal circuit.
 
CMP has failed
 
ECM has failed
 

Trouble Code: P0420



Catalyst System Low Efficiency

Trouble Code: P0420



Catalyst System Low Efficiency (Bank 1)

Possible Causes:



Air leaks at the exhaust manifold or in the exhaust pipes
 
Base engine problems (i.e., high engine oil or coolant usage)
 
Catalytic converter is damaged, contaminated or has failed
 
Continuous engine misfire conditions, or weak or low coil output
 
Front HO2S or rear HO2S is contaminated with fuel or moisture
 
Rear HO2S is loose in the mounting hole (check it for a leak)
 
Front HO2S older (aged) than the rear HO2S (HO2S-12 is lazy)
 

Trouble Code: P0442



Evaporative Emissions (EVAP) System Small Leak Detected

Possible Causes:



To help locate intermittent leaks, use the J 41413-200 Evaporative Emission System Tester (EEST) to introduce smoke into the EVAP system. Move all EVAP components while observing smoke with theJ 41413-SPT High Intensity White Light.
 
To improve the visibility of the smoke exiting the EVAP system, observe the suspected leak area from different angles with the J 41413-SPT .
 
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.
 

Trouble Code: P0442



Evaporative Emissions (EVAP) System Small Leak Detected

Possible Causes:



To help locate intermittent leaks, use the J 41413-200 Evaporative Emission System Tester (EEST) to introduce smoke into the EVAP system. Move all EVAP components while observing smoke with theJ 41413-SPT High Intensity White Light.
 
To improve the visibility of the smoke exiting the EVAP system, observe the suspected leak area from different angles with the J 41413-SPT .
 
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.
 
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.
 

Trouble Code: P0442



Evaporative Emission (EVAP) System Small Leak Detected

Possible Causes:



Damaged EVAP purge solenoid
 
Damaged EVAP vent valve or EVAP canister
 
Incorrectly routed, kinked, or damaged EVAP pipes and hoses
 

Trouble Code: P0443



Evaporative Emission (EVAP) Purge Solenoid Control Circuit

Trouble Code: P0443



EVAP Purge Solenoid Control Circuit Malfunction

Possible Causes:



Purge solenoid control circuit is open or shorted to ground
 
Purge solenoid control circuit is shorted to system power (B+)
 
Purge solenoid power circuit is open (test the IGN1 fuse)
 
Purge solenoid is damaged or has failed
 
ECM has failed
 

Trouble Code: P0446



Evaporative Emission (EVAP) Vent System Performance

Possible Causes:



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.
 
An EVAP canister filter that is restricted can cause this DTC to set. Refer to Evaporative Emission System Cleaning .
 

Trouble Code: P0446



Evaporative Emissions (EVAP) Vent System Performance

Possible Causes:



EVAP vent fresh air hose is clogged, kinked or restricted
 
EVAP Vent solenoid is contaminated, damaged or has failed
 
FTP sensor is out-of-calibration, damaged or "skewed"
 
ECM has failed
 

Trouble Code: P0449



Evaporative Emission (EVAP) Vent Solenoid Control Circuit

Trouble Code: P0449



EVAP Vent Solenoid Control Circuit Malfunction

Possible Causes:



Vent solenoid control circuit is open or shorted to ground
 
Vent solenoid control circuit is shorted to system power (B+)
 
Vent solenoid power circuit is open (test the ENG1 fuse)
 
Vent solenoid is damaged or has failed
 
ECM has failed
 

Trouble Code: P0451



Fuel Tank Pressure (FTP) Sensor Performance

Possible Causes:

P0451 and P0454



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

Trouble Code: P0451



Fuel Tank Pressure (FTP) Sensor Performance

Possible Causes:



EVAP purge solenoid valve
 
FTP sensor
 
EVAP canister vent solenoid valve and vent pipe for a blockage or restriction
 

Trouble Code: P0452



Fuel Tank Pressure (FTP) Sensor Circuit Low Voltage

Possible Causes:

P0451 and P0454



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

Trouble Code: P0453



Fuel Tank Pressure (FTP) Sensor Circuit High Voltage

Possible Causes:

P0451 and P0454



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

Trouble Code: P0454



Fuel Tank Pressure (FTP) Sensor Intermittent

Possible Causes:

P0451 and P0454



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

Trouble Code: P0454



Evaporative Emission (EVAP) System Large Leak Detected

Possible Causes:



Inspect for a damaged fuel filler neck seal surface.
 
Blockage or restriction in the EVAP purge solenoid valve, purge pipe, EVAP canister, or vapor pipe,
 
Inspect for a loose, missing, damaged, or incorrect fuel fill cap
 
FTP sensor has failed
 

Trouble Code: P0455



Evaporative Emission (EVAP) System Large Leak

Possible Causes:



A loose, missing, incorrect, or damaged fuel fill cap may cause this DTC to set.
 
To help locate intermittent leaks, use the J 41413-200 Evaporative Emission System Tester (EEST) to introduce smoke into the EVAP system. Move all EVAP components while observing smoke with theJ 41413-SPT High Intensity White Light . Introducing smoke in 15-second intervals will allow less pressure into the EVAP system. When the system is less pressurized, the smoke will sometimes escape in a more condensed manner.
 
To improve the visibility of the smoke exiting the EVAP system, observe the suspected leak area from different angles with the J 41413-SPT .
 
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.
 
For intermittent conditions, refer to Testing for Intermittent Conditions and Poor Connections .
 

 
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