Testing/Circuit Testing)
* Connector Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic
Procedures/Connector Repairs/Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (See: Testing and Inspection/Component Tests and General Diagnostics/General
Electrical Diagnostic Procedures/Circuit Testing/Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Wiring
Repairs/Wiring Repairs)
Scan Tool Reference
Control Module References (See: Testing and Inspection/Programming and Relearning) for scan tool information
Circuit/System Verification
1. With the engine running, monitor the following ignition control (IC) circuit status parameters with a scan tool:
* Cylinder 1-8 IC Ckt. Short Gnd Test Status
* Cylinder 1-8 IC Ckt. Open Test Status
* Cylinder 1-8 IC Ckt. Short to Volts Test Status
锟斤拷Each parameter should display OK.
2. With the engine running, observe the Misfire Current counters with a scan tool.
锟斤拷The counters should not be incrementing.
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.
Circuit/System Testing
1. With the engine running, monitor the Cylinder 1-8 IC Circuit Status parameters with a scan tool.
锟斤拷If a short to GND or Open status test displays FAULT, test for an open/high resistance or short to ground on the affected IC circuit
terminal C.
锟斤拷If a short to volts status test displays FAULT, test for a short to voltage on the affected IC circuit terminal C.
Important: A high resistance on any IC circuit can cause a misfire condition before DTCs P0351-P0358 set.
2. Exchange the affected ignition coil/module with the ignition coil/module of a cylinder that is not affected.
3. Start and run the engine. With a scan tool, monitor the IC circuit parameters and the Misfire Current counters.
锟斤拷If the circuit status fault identified or the misfire transfers with the ignition coil/module, replace the ignition coil/module assembly.
锟斤拷If the circuit status fault identified or the misfire does not transfer with the ignition coil/module, replace the ECM.
Repair Instructions
* Ignition Coil Replacement (See: Powertrain Management/Ignition System/Ignition Coil/Service and Repair)
* Engine Control Module Replacement (See: Powertrain Management/Computers and Control Systems/Engine Control Module/Service and
Repair)
* Engine Control Module Programming and Setup (See: Powertrain Management/Computers and Control Systems/Engine Control
Module/Testing and Inspection)
Repair Verification
Important: An IC circuit fault condition will result in an engine misfire, and under certain driving conditions could possibly overheat the
3-way catalytic converter.
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. Start and run the engine. With a scan tool, monitor the IC circuit status parameters. All IC circuit status parameters should display OK.
锟斤拷If 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.
4. 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).
