2010 Cadillac CTS Sedan AWD V6-3.6L Page 1301
瀚慖f there is no spark, refer to Electronic Ignition System Diagnosis (See: Powertrain Management/Computers and Control
Systems/Testing and Inspection/Component Tests and General Diagnostics/Electronic Ignition System Diagnosis) for diagnosis of the
ignition coil.
6. Ignition OFF, remove the spark plug from the misfiring cylinder. Verify that the spark plug does not exhibit the following conditions:
* Gas, coolant, or oil fouled-Refer to Spark Plug Inspection (See: Engine, Cooling and Exhaust/Engine/Tune-up and Engine Performance
Checks/Spark Plug/Testing and Inspection).
* Cracked, worn, incorrectly gapped-Refer to Ignition System Specifications (See: Powertrain Management/Ignition
System/Specifications).
瀚慖f there is a condition with the spark plug, replace the spark plug.
7. Exchange the suspected spark plug with another cylinder that is operating correctly.
8. Engine idling, observe the scan tool Misfire Current Counter parameters. The misfire should not follow the spark plug exchange.
瀚慖f the misfire follows the spark plug, replace the spark plug.
9. If all conditions test normal, test or inspect for the following:
* A lean or rich Q17 fuel injector-Refer to Fuel Injector Solenoid Coil Test (w/LLT) (See: Powertrain Management/Computers and
Control Systems/Testing and Inspection/Component Tests and General Diagnostics/Fuel Injector Solenoid Coil Test)Fuel Injector
Solenoid Coil Test (w/LF1) (See: Powertrain Management/Fuel Delivery and Air Induction/Fuel Injector/Testing and Inspection).
* An engine mechanical condition-Refer to Symptoms - Engine Mechanical (See: Engine, Cooling and Exhaust/Engine/Testing and
Inspection/Symptom Related Diagnostic Procedures/Symptoms - Engine Mechanical).
Repair Instructions
* Spark Plug Replacement (See: Engine, Cooling and Exhaust/Engine/Tune-up and Engine Performance Checks/Spark Plug/Service and
Repair)
* Ignition Coil Replacement - Bank 1 (See: Powertrain Management/Ignition System/Ignition Coil/Service and Repair/Ignition Coil
Replacement - Bank 1)
* Ignition Coil Replacement - Bank 2 (See: Powertrain Management/Ignition System/Ignition Coil/Service and Repair/Ignition Coil
Replacement - Bank 2)
Repair Verification
1. Install any components or connectors that have been removed or replaced during diagnosis.
2. Perform any adjustment, programming, or setup procedures that are required when a component or module is removed or replaced.
3. Clear the DTCs.
4. Turn OFF the ignition for 60 s.
5. If the repair was related to a DTC, duplicate the Conditions for Running the DTC and use the Freeze Frame/Failure Records, if applicable, in
order to verify the DTC does not reset. If the DTC resets or another DTC is present, refer to Diagnostic Trouble Code (DTC) List - Vehicle
(See: Diagnostic Trouble Code Descriptions/Diagnostic Trouble Code (DTC) List - Vehicle) and perform the appropriate diagnostic
procedure.
6. To verify that the performance of the catalytic converter has not been affected by the condition that set this DTC, perform the Repair
Verification for DTC P0420 or P0430. Refer to DTC P0420 or P0430 (See: P Code Charts/P0420).
P0305
DTC P0300-P0306 (w/LLT)
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic System
Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Strategy Based Diagnosis) for an
overview of the diagnostic approach.
* Diagnostic Procedure Instructions (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic Procedure
Instructions) provides an overview of each diagnostic category.
DTC Descriptors
DTC P0300
- Engine Misfire Detected
DTC P0301
- Cylinder 1 Misfire Detected
