Diagnostic Aids
* This test procedure requires that the vehicle battery has passed a load test and is completely charged. Refer to Battery Inspection/Test (See:
Starting and Charging/Testing and Inspection/Component Tests and General Diagnostics/Battery Inspection/Test).
* A high resistance condition on any IC circuit can cause an engine misfire without setting DTC P0351-P0358.
Reference Information
Schematic Reference
Engine Controls Schematics (See: Diagrams/Electrical Diagrams/Powertrain Management/System Diagram)
Connector End View Reference
Component Connector End Views (See: Diagrams/Connector Views)
Description and Operation
Electronic Ignition System Description (See: Powertrain Management/Computers and Control Systems/Description and Operation/Electronic
Ignition System Description)
Electrical Information Reference
* Circuit Testing (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Circuit
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
