DTC C2100 Dodge

Description

Engine started; and the PCM detected an unexpected high voltage condition on the ICM signal circuit for at least 300 3X reference periods (100 crankshaft revolutions). The ICM has independent power and ground circuits that connect to the PCM. They are the IC timing signal, IC timing control signal, low-resolution engine speed signal and low reference (ground) signal. The ICM sends 3X signals to the PCM. The IC module controls the timing advance during engine cranking. Control of the spark timing advance changes to PCM control after the PCM receives the second 3X signal. The PCM applies 50volts to the IC timing signal circuit in order to switch the timing advance to PCM control of spark timing.