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???
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).