P0351

Steps 1 - 7:

Step 8:

DTC P0351 Ignition Coil "A" Primary/Secondary Circuit Malfunction




Circuit Description
The ignition control circuit provides a zero volt or a 5 volt signal to the ignition control module. The normal circuit voltage is zero volts. When the module receives the 5 volt signal from the powertrain control module (PCM), it provides a ground path for the B+ voltage supplied to the ignition primary coil. When the PCM turns off the 5 volts to the module, the module will remove the ground path of the ignition primary coils; causing the magnetic field produces a voltage in the secondary coils which fires the spark plug.

The circuit between the PCM and the ignition control module is monitored for an open circuit, short to voltage, and short to ground. When the PCM detects a problem in the ignition control circuit, it will set DTC P0351. DTC P0351 is a type A code.

Conditions for Setting the DTC
- Ignition ON.
- Output voltage is not equal to 5 volts when output is ON.
- Output voltage is not equal to 0 volt when output is OFF.
- Twenty test failures within 40 samples of continuous circuit monitoring.

Action Taken When the DTC Sets
- The PCM will illuminate the malfunction indicator lamp (MIL) the first time the fault is detected.
- The PCM will store conditions which were present when the DTC was set as Freeze Frame and in the Failure Records data.

Conditions for Clearing the MIL/DTC
- The PCM will turn the MIL OFF on the third consecutive trip cycle during which the diagnostic has been run and the fault condition is no longer present.
- A history DTC P0351 will clear after 40 consecutive warm-up cycles have occurred without a fault.
- DTC P0351 can be cleared by using the Scan Tool's "Clear Info" function.

Diagnostic Aids
Check for the following conditions:
- Poor connection at the PCM - Inspect the harness connectors for backed-out terminals, improper mating, broken locks, improperly formed or damaged terminals, and poor terminal-to-wire connections.
- Damaged harness - Inspect the wiring harness for damage: Open circuits, shorts to ground, or shorts to Voltage. If the harness appears to be OK, observe the Tech 2 display related to DTC P0351 while moving the connector and wiring related to the ignition system. A change in the display will indicate the location of the fault.

Reviewing the Failure Records vehicle mileage since the diagnostic test last failed may help determine how often the condition that caused the DTC to be set occurs. This may assist in diagnosing the condition.