P0351

DTC P0351

CIRCUIT DESCRIPTION
The enhanced ignition system uses the crankshaft position (CKP) sensor to provide a timing input to the control module. Ignition control (IC) spark timing for each cylinder is based on this input. The control module provides the ignition timing signal to the ignition control module (ICM) to control the ignition coil. Each timing pulse detected by the ICM allows the ICM to energize the ignition coil. A large secondary ignition voltage is induced in the secondary coil winding by the primary coil winding. This high voltage is switched to the correct spark plug by the distributor. If the powertrain control module (PCM) detects an unusually high or low voltage on the ignition signal circuit, DTC P0351 sets.

DTC DESCRIPTOR
This diagnostic procedure supports the following DTC:
DTC P0351 Ignition Coil 1 Control Circuit

CONDITIONS FOR RUNNING THE DTC
The engine is cranking.

CONDITIONS FOR SETTING THE DTC
The ignition control voltage is not between 0.04-4.9 volts.

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.

TEST DESCRIPTION

Steps 1 - 11:

Steps 12 - 18:

The numbers below refer to the step numbers on the diagnostic table.
2. This step determines if the DTC is an intermittent.
3. This step verifies if the IC timing signal from the PCM is available at the ignition control module.