Code P023, Ignition Control Circuit Problem: Action
PCM turns on MIL and will not enable spark timing control. Engine will start and run on base timing. PCM disables EGR solenoid.
NOTE:
Test numbers refer to numbers on diagnostic chart.
- When circuit No. 423 is shorted to ground, engine will start hard with long cranking periods. When PCM detects the grounded circuit, the by-pass line will be shifted low.
- With distributor reference and reference ground jumpered to PCM, engine will run on back-up spark. Checks for proper ground connection between PCM and engine and PCM and ignition control module.
- Checks if PCM is providing an ignition control output on circuit No. 423.
- Checks if ignition control module is able to ground ignition control signal with an open by-pass circuit.
- Checks if ignition control module is able to recognize a voltage on by-pass circuit and stop grounding ignition control (PCM controlled timing).
- Checks if by-pass signal being sent by PCM is being received by ignition control module and if module is interpreting by-pass voltage correctly by switching off the ground circuit to ignition control.
- If ignition control circuit is okay, then fault is in 6-way connector. Check for proper mating and proper pin contact. If connector is okay, clear codes and retest.