P0350 Ignition Coil Primary circuit fault trouble code

Discussion in '2005 - 2009 Specific Tech' started by gunnerdog, Feb 3, 2010.

  1. Has anybody seen this troubel code P0350 Ignition Coil Primary circuit fault? I recently changed my plugs back to stock plugs from HTO because I was no longer using nitrous. I have very rough idle now. Any ideas???
  2. P0350 Undetermined Circuit Malfunction

    The DTC indicates a fault in the PRIMARY (low voltage) side of the ignition circuit. Think wiring fault, disconnected/loose connections, or electrical interference.

    Since there is a specific DTC for each cylinder, the fact that the Undetermined code was used (last digit 0) indicates the problem is on multiple cylinders.

    Has any wiring changes been done? Any after market COP's? Any adapters between the COP and wiring harness? Have the electrical interference capacitors been removed/disconnected? Any nicks or other damage to the wiring harness? Any damaged COP boot insulators allowing spark to escape?

    >>from Ford service CD
    P0350 - Ignition Coil (Undetermined) Primary/ Secondary Circuit Malfunction

    Each ignition primary circuit is continuously monitored. The test fails when the PCM does not receive a valid IDM pulse signal from the ignition module (integrated in PCM).

    • Open or short in Ignition START/RUN circuit
    • Open coil driver circuit
    • Coil driver circuit shorted to ground
    • Damaged coil
    • Damaged PCM
    • Coil driver circuit shorted to VPWR
  3. I would go over everything, check the plugs, coil connector to plug and connections to harness. Make sure its all on securely.