There are three dual tower ignition coils integrated with the ignition control module (ICM). The ICM contains coil driver circuits that operate the three coils. The engine control module (ECM) controls the spark event for each coil through the three individual ignition coil control circuits. When the ECM commands an ignition coil control 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 ignition coil control 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. The ICM wiring includes the following circuits:

The ignition coil 1 control circuit enables the spark event for cylinders 1 and 4. The ignition coil 2 control circuit enables the spark event for cylinders 2 and 5. The ignition coil 3 control circuit enables the spark event for cylinders 3 and 6. If the ECM detects that the coil control circuit has an incorrect voltage level, DTC P0351-P0353 will set.

The ECM detects one of the following failures on an ignition coil control circuit:

DTCs P0351-P0353 are type B DTCs.

DTCs P0351-P0353 are type B DTCs.

This test procedure requires that the vehicle battery has passed a load test and is completely charged. Refer to Battery Inspection/Test .

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Description and Operation

Electronic Ignition (EI) System Description

Electrical Information Reference

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

1. Engine running, with a scan tool, monitor the following ignition coil control circuit status parameters. Each parameter should display OK.

•	Ignition Coil 1, 2, and 3 Control Circuit Short to Ground Test Status

•	Ignition Coil 1, 2, and 3 Control Circuit Open Test Status

•	Ignition Coil 1, 2, and 3 Control Circuit Short to Voltage Test Status

2. Operate the vehicle within the conditions for running the DTC. You may also operate the vehicle within the conditions that are captured in the Freeze Frame/Failure Records Data List.

1. Turn OFF the ignition.
2. Disconnect the ECM C2 harness connector.
3. Disconnect the ignition control module harness connector.

Important: A high resistance on an ignition coil control circuit can cause a misfire condition, before DTC P0351-P0353 sets.

4. Test the affected ignition coil control circuit for the fault condition identified in Circuit/System Verification.

⇒	If a condition is detected, repair the circuit as required.

5. Connect the ECM C2 harness connector.
6. Connect jumper wires from the harness connector of the ICM to the corresponding terminals of the ICM.
7. Using the jumper wires, exchange the affected ignition coil control circuit with a known good ignition coil control circuit. Also exchange the spark plug wires of the corresponding coils.
8. Start and run the engine. With a scan tool, monitor the ignition coil control circuit parameters.

⇒	If the circuit status fault identified in Circuit/System Verification transfers with the suspect ignition coil control circuit, replace the ECM.

⇒	If the circuit status fault identified in Circuit/System Verification does not transfer with the ignition coil/module, replace the ICM.

Important: An ignition coil control circuit fault 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 ignition coil control circuit status parameters. All ignition coil control circuit status parameters should display OK.

⇒	If another DTC is present, refer to Diagnostic Trouble Code (DTC) List - Vehicle and perform the appropriate diagnostic procedure.

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 .