Component Tests and General Diagnostics
CIRCUIT DESCRIPTIONThe Ignition Control (IC) module has independent power and ground circuits. The circuits between the IC module and the Powertrain Control Module (PCM) consist of the following:
^ The low reference circuit
^ The low resolution engine speed signal
^ The two IC timing control signals
- For cylinders 1 and 4
- For cylinders 2 and 3
The IC module and PCM use the low resolution engine speed signal to control ignition operation. The low resolution engine speed signal is derived from the Crankshaft Position (CKP) sensor, which is connected directly to the IC module.
DIAGNOSTIC AIDS
^ A small amount of resistance in the battery positive voltage circuit to the PCM may cause a no start. Test the battery positive voltage circuit for excessive resistance or corrosion. Refer to Wiring Repairs in Diagrams.
^ The PCM grounds will cause a NO START only if all of them are not making a good connection. Refer to Testing for Intermittent and Poor Connections in Diagrams.
^ If the CKP sensor is loose it may cause an intermitted NO START by moving away from the reluctor wheel. Inspect the sensor and matting surface for being clean and tight.
TEST
Steps 1-5:
Steps 6-14:
Steps 15-24:
