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 and 4 Control CircuitDTC P0352: Ignition Coil 2 and 3 Control Circuit
Diagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Ignition 1 Voltage | * | ** | -- | -- |
Ignition Coil 1 and 4 Control Circuit | * | P0300, P0351 | P0300, P0351 | -- |
Ignition Coil 2 and 3 Control Circuit | * | P0300, P0352 | P0300, P0352 | -- |
* The Engine Cranks but Does Not Run and opens the fuse that supplies voltage to the ignition coils. ** The Engine Cranks but Does Not Run. | ||||
Circuit/System Description
Ignition 1 voltage is supplied to the ignition coil. The engine control module (ECM) provides a ground for the ignition coil (IC) control circuits. When the ECM removes the ground path of the ignition primary coil, the magnetic field produced by the coil collapses. The collapsing magnetic field produces a voltage in the secondary coil which ignites the spark plugs. The sequencing and timing are controlled by the ECM. The ignition coils consist of the following circuits:
| • | The ignition 1 voltage |
| • | The IC 1 and 4 control |
| • | The IC 2 and 3 control |
Conditions for Running the DTC
| • | The engine is running. |
| • | The DTCs run continuously once the above condition is met. |
Conditions for Setting the DTC
The ECM detects an open or short to ground or voltage on the IC circuit.
Action Taken When the DTC Sets
| • | DTC P0351 and P0352 are Type B DTCs. |
| • | The ECM commands open loop fuel control. |
Conditions for Clearing the DTC
DTC P0351 and P0352 are Type B DTCs.
Diagnostic Aids
The mounting bracket for the coil assembly provides the ground for the ignition coils. Ensure the mounting bolts are torqued to the correct specification. Refer to Fastener Tightening Specifications.
Reference Information
Schematic Reference
Electrical Information Reference
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
- Engine running, observe the DTC information with a scan tool. DTC P0351 and P0352 should not set.
- Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the ignition coil.
- Ignition ON, verify that a test lamp illuminates between the ignition 1 voltage circuit terminal B and ground.
- Connect a DMM between the appropriate ignition control circuit and ground.
- Engine cranking, test for more than 2 hertz between the appropriate ignition control circuit and ground.
- If all circuits test normal, test or replace the ignition coil.
| ⇒ | If the test lamp does not illuminate, test the ignition 1 voltage circuit for a short to ground or an open/high resistance. If the circuit tests normal and the ignition 1 voltage circuit fuse is open, test all components connected to the ignition 1 voltage circuit and replace as necessary. |
Important: Set the DMM to the AC Hertz scale for this test.
| • | Ignition coil 1 and 4 control terminal C |
| • | Ignition coil 2 and 3 control terminal A |
| ⇒ | If less than the specified range, test the ignition control circuit for a short to voltage, short to ground or an open/high resistance. If the circuit tests normal, replace the ECM. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for ECM replacement, setup, and programming |
