Test A: The Powertrain Control Module (PCM) Does Not Respond To The Scan Tool

PINPOINT TEST A: THE POWERTRAIN CONTROL MODULE (PCM) DOES NOT RESPOND TO THE SCAN TOOL

A1-A2:

A2-A3:

A4:

Normal Operation
The PCM communicates with the scan tool through the high speed controller area network (HS-CAN). Circuits VDB04 (WH/BU) (HS-CAN +) and VDB05 (WH) (HS-CAN -) provide the network connection to the PCM. The PCM shares the HS-CAN network with the transmission control module (TCM), the anti-lock brake system (ABS) module, the restraints control module (RCM), the four wheel drive (4WD) control module (if equipped), the air suspension module (if equipped) and the instrument cluster.

DTC U0100 - sets in a module which had attempted to communicate with the PCM and failed.

Possible Causes
- Circuit VDB04 (WH/BU) open (HS-CAN +)
- Circuit VDB05 (WH) open (HS-CAN -)
- PCM