Circuit Description
WARNING: This page is about a different car, the 2004 Pontiac Aztek and 2004 Buick Rendezvous. However, it is still accessible from the selected car via links, so may be relevant.
The ignition control module (ICM) has independent power and ground circuits. The circuits between the ICM and the powertrain control module (PCM) consists of the following circuits:
- The ignition control (IC) timing signal circuit
- The IC timing control circuit
- The low resolution engine speed signal circuit
- The low reference signal circuit
The ICM sends 3X signals to the PCM and controls the timing advance during engine cranking. The timing advance changes to PCM control after the following actions occur:
- The PCM receives the second 3X signal
- The PCM applies 5 volts to the IC timing signal circuit.
- The timing advance switches to PCM control.
If the PCM detects an open in the IC timing control circuit, DTC P1351 sets.