PCM Messages Not Received

Test 1 - 2:

Test 3:

SYMPTOM
PCM MESSAGE NOT RECEIVED

WHEN MONITORED
With the ignition on.

SET CONDITION
When the Instrument Cluster detects no PCI Bus communication with the PCM for 20 seconds. The cluster will illuminate the CHECK ENGINE indicator and the VF will display NO BUS. The Tachometer, Speedometer, and Temperature gauge pointers will be driven against their pointer stops. The Engine Temp, Charging System, and Cruise indicators will latch to their last known state.

POSSIBLE CAUSES
- PCM message not received
- No communication with the PCM
- PCI bus circuit open
- Powertrain control module