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

### Diagnostic Fault Information

Circuit | Short to Ground | High Resistance | Open | Short to Voltage | Signal Performance
--- | --- | --- | --- | --- | ---
Ignition Coil 1 Control Circuit | P0351 | P0351 | P0351 | P0351 | P0351
Ignition Coil 2 Control Circuit | P0352 | P0352 | P0352 | P0352 | P0352
Ignition Coil 3 Control Circuit | P0353 | P0353 | P0353 | P0353 | P0353
Ignition Coil 4 Control Circuit | P0354 | P0354 | P0354 | P0354 | P0354

### Circuit/System Description

The ignition system uses individual ignition coil/module assemblies for each cylinder. The engine control module (ECM) controls the individual coils by transmitting timing pulses on the ignition control (IC) circuit of each ignition coil/module to enable a spark event. The ECM monitors each IC circuit for improper voltage levels. Each ignition coil/module has the following circuits:

• | Ignition voltage

• | Ground

• | IC

• | Low reference

### Conditions for Running the DTC

• | The engine is running.

• | DTCs P0351-P0354 run continuously when the above condition is met.

### Conditions for Setting the DTC

• | The ECM detects an open on the circuit or the ignition coil/module for less than 1 second.

| OR

• | The ECM detects a short to ground on the circuit or the ignition coil/module for less than 1 second.

| OR

• | The ECM detects a short to voltage on the circuit or the ignition coil/module for less than 1 second.

### Action Taken When the DTC Sets

DTCs P0351-P0354 are Type B DTCs.

### Conditions for Clearing the MIL/DTC

DTCs P0351-P0354 are Type B DTCs.

### Reference Information

#### Schematic Reference

Engine Controls Schematics

#### Connector End View Reference

Component Connector End Views

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

#### Scan Tool Reference

Control Module References for scan tool information

### Circuit/System Verification

• | Start and idle the engine.

• | Observe the scan tool DTC Information and the Misfire Current Cyl. parameters. This will indicate the affected ignition coil/modules, and if the condition is current.

• | 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. Ignition OFF for 90 seconds, disconnect the ECM.
2. Test the affected IC circuit terminal 3 for an open, a high resistance, a short to ground and for a short to voltage.

⇒ | If a fault is found, repair the circuit as needed.

3. Connect the ECM.
4. Exchange the affected ignition coil/module with the ignition/coil module of a good cylinder.
5. Start the engine and observe the scan tool.

⇒ | If the DTC or the misfire transfers with the suspect ignition/coil module, replace as needed.

⇒ | If the DTC or the misfire does not transfer with the suspect ignition/coil module, replace the ECM.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Ignition Coil Replacement

• | Control Module References for ECM replacement, setup, and programming