P0351

DTC P0351

DTC DESCRIPTOR

DTC P0351
Ignition Coil 1 Control Circuit

DTC P0352
Ignition Coil 2 Control Circuit

DTC P0353
Ignition Coil 3 Control Circuit

DIAGNOSTIC FAULT INFORMATION

IMPORTANT: Always perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Testing and Inspection






CIRCUIT/SYSTEM DESCRIPTION
There are 3 dual-tower ignition coils integrated with the ignition control module (ICM). The ICM contains coil driver circuits that operate the 3 coils. The ICM wiring includes the following circuits:
- An ignition 1 voltage circuit
- A ground circuit
- An ignition coil 1 control circuit
- An ignition coil 2 control circuit
- An ignition coil 3 control circuit
- A low reference circuit

The engine control module (ECM) controls each ignition coil by transmitting timing pulses to the ICM on each of the ignition coil control circuits to enable properly timed spark events. The ignition coil 1 controls spark for companion cylinders 1 and 4. The ignition coil 2 controls spark for companion cylinders 2 and 5. The ignition coil 3 controls spark for companion cylinders 3 and 6.

CONDITIONS FOR RUNNING THE DTC
- The engine is cranking or running.
- The DTCs run continuously when the above condition is met.

CONDITIONS FOR SETTING THE DTC
The PCM detects a fault in an ignition coil control circuit for 90 out of 100 engine cycles.

ACTION TAKEN WHEN THE DTC SETS
- The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
- The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

CONDITIONS FOR CLEARING THE MIL/DTC
- The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
- A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
- A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
- Clear the MIL and the DTC with a scan tool.

CIRCUIT/SYSTEM VERIFICATION
1. With the engine running, observe the Cylinder 1 and 4 IC Circuit Status, Cylinder 2 and 5 IC Circuit Status, and the Cylinder 3 and 6 ignition control (IC) Circuit Status parameters with the scan tool. All of the parameters should display OK.
- If the parameters display anything other than OK, continue with Circuit/System Testing.
2. With the engine running, observe the Misfire Current counters using the scan tool. The counters should not be incrementing.
- If the counters are incrementing for a pair of companion cylinders, continue with Circuit/System Testing.

CIRCUIT/SYSTEM TESTING
1. With the engine running, observe the Cylinder 1 and 4 IC Circuit Status, Cylinder 2 and 5 IC Circuit Status, and the Cylinder 3 and 6 IC Circuit Status parameters with the scan tool.
- If a parameter displays short Gnd/Open, test for an open/high resistance or a short to ground in the affected IC circuit. All wire circuit resistance should measure less than 2 ohms.
- If a parameter displays short to B+, test for a short to voltage in the affected IC circuit.
2. Connect jumper wires from the harness connector of the ICM to the corresponding terminals of the ICM.
3. Using the jumper wires, exchange the affected IC control circuit with a known good IC control circuit. Also exchange the spark plug wires of the corresponding coils.
4. Start the engine.
5. Observe the Misfire Current counters with the scan tool.
- If the misfire transfers with the suspect IC control circuit, replace the ECM.
- If the misfire remains with the coil, replace the ICM.

COMPONENT TESTING
- With positive polarity to the low reference terminal, measure for 9,000-11,000 ohms at 20-23°C (68-74°F) room temperature between each of the ignition coil control terminals and the low reference terminal of the ICM.
- If the resistance is not within the specified range, replace the ICM.
- Measure for 7,000-15,000 ohms at 20-23°C (68-74°F) room temperature between each pair of coil towers on the ICM.
- If the resistance is not within the specified range, replace the ICM.

REPAIR INSTRUCTIONS

IMPORTANT: Always perform the Diagnostic Repair Verification after completing the diagnostic procedure.
- Control Module References for ECM replacement, setup, and programming
- Ignition Coil(s) Replacement for ICM and Coil assembly replacement. Verification Tests