Code 23, Ignition Control Circuit(S): Notes

Code will set if Code 35 is not set and engine speed is less than about 400 RPM and PCM detects voltage on IC signal circuit, or if PCM does not detect voltage on IC signal circuit when engine speed exceeds about 400 RPM and at least 16 fuel reference pulses have been detected by PCM.

1. 1)  Checks if Code 35 is set because of a problem in reference low circuit.
2. 2)  Checks to see if Code 23 was set during crank or while engine was running.
3. 3)  Checks if there is a short to voltage on by-pass circuit or if a PCM failure is causing the ignition control system to be in by-pass spark control when it should not be.
4. 4)  Checks to see if there is an open in IC circuit that is causing no ignition control pulses to reach the ignition module or if pulses are reaching the ignition control module and it is doing nothing with them.
5. 5)  Checks for short to voltage on by-pass circuit.