For 1990-2009 cars

### Diagnostic Instructions

• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

• | Review Strategy Based Diagnosis for an overview of the diagnostic approach.

• | Diagnostic Procedure Instructions provides an overview of each diagnostic category.

### DTC Descriptors

DTC P0351: Ignition Coil 1 Control Circuit
DTC P0352: Ignition Coil 2 Control Circuit
DTC P0353: Ignition Coil 3 Control Circuit
DTC P0354: Ignition Coil 4 Control Circuit
DTC P0355: Ignition Coil 5 Control Circuit
DTC P0356: Ignition Coil 6 Control Circuit
DTC P0357: Ignition Coil 7 Control Circuit
DTC P0358: Ignition Coil 8 Control Circuit

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
Ignition Coil 1 Control Circuit | P0300, P0351 | P0300, P0351 | P0300, P0351 | --
Ignition Coil 2 Control Circuit | P0300, P0352 | P0300, P0352 | P0300, P0352 | --
Ignition Coil 3 Control Circuit | P0300, P0353 | P0300, P0353 | P0300, P0353 | --
Ignition Coil 4 Control Circuit | P0300, P0354 | P0300, P0354 | P0300, P0354 | --
Ignition Coil 5 Control Circuit | P0300, P0355 | P0300, P0355 | P0300, P0355 | --
Ignition Coil 6 Control Circuit | P0300, P0356 | P0300, P0356 | P0300, P0356 | --
Ignition Coil 7 Control Circuit | P0300, P0357 | P0300, P0357 | P0300, P0357 | --
Ignition Coil 8 Control Circuit | P0300, P0358 | P0300, P0358 | P0300, P0358 | --

### Circuit/System Description

The ignition system on this engine uses an individual coil/module for each cylinder. The engine control module (ECM) controls the spark event for each cylinder through the eight individual ignition control (IC) circuits. When the ECM commands the IC circuit ON, electrical current will flow through the primary winding of the ignition coil, creating a magnetic field. When a spark event is requested, the ECM will command the IC circuit OFF, interrupting current flow through the primary winding. The magnetic field created by the primary winding will collapse across the secondary coil windings, producing a high voltage across the spark plug electrodes. The ECM uses information from the crankshaft position (CKP) sensor, and the camshaft position (CMP) sensor for sequencing and timing of the spark events. Each ignition coil/module assembly has the following circuits:

• | Ignition voltage

• | Ground

• | Ignition control (IC)

• | Low reference

If the ECM detects that the IC circuit has an incorrect voltage level, DTC P0351-P0358 will set.

### Conditions for Running the DTC

• | The ignition is ON.

• | DTC P0351-P0358 runs continuously when the above condition is met.

### Conditions for Setting the DTC

The ECM detects one of the following failures on the IC circuit:

• | An open

• | A short to ground

• | A short to voltage

### Action Taken When the DTC Sets

DTCs P0351-P0358 are Type B DTCs.

### Conditions for Clearing the DTC

DTCs P0351-P0358 are Type B DTCs.

### Diagnostic Aids

• | This test procedure requires that the vehicle battery has passed a load test and is completely charged. Refer to 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

#### Connector End View Reference

Component Connector End Views

#### Description and Operation

Electronic Ignition (EI) System Description

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### Scan Tool Reference

Control Module References 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

⇒ | Each parameter should display OK.

2. With the engine running, observe the Misfire Current counters with a scan tool.

⇒ | 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.

⇒ | 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.

⇒ | 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.

⇒ | If the circuit status fault identified or the misfire transfers with the ignition coil/module, replace the ignition coil/module assembly.

⇒ | 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

• | Engine Control Module Replacement

• | Engine Control Module Programming and Setup

### 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.

⇒ | If another DTC is present, refer to 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.