Test A: The Powertrain Control Module (PCM) Does Not Respond to the Scan Tool, or No High Speed Controller Area Network (HS-CAN
PINPOINT TEST A: THE POWERTRAIN CONTROL MODULE (PCM) DOES NOT RESPOND TO THE SCAN TOOL, OR NO HIGH SPEED CONTROLLER AREA NETWORK (HS-CAN) COMMUNICATIONA1-A2:
A3-A4:
A5-A8:
A8-A10:
A10-A12:
A12-A14:
A14-A16:
A16-A18:
A18-A19:
A20-A23:
A24:
Normal Operation
The PCM communicates with the scan tool through the HS-CAN. Circuits 1827 (WH/LG) (HS-CAN +) and 1828 (PK/LG) (HS-CAN -) provide the network connection to the PCM. The PCM shares the HS-CAN network with the anti-lock brake system (ABS) module, the air suspension module or variable assist power steering (VAPS) module, the instrument cluster and the fire suppression module (if equipped). Voltage for the PCM is provided by circuits 361 (RD) and 729 (RD/WH). Circuits 57 (BK) and 570 (BK/WH) provide ground.
Possible Causes
- Fuse
- Circuit 57 (BK) open
- Circuit 361 (RD) open
- Circuit 570 (BK/WH) open
- Circuit 729 (RD/WH) open
- Circuit 1827 (WH/LG) open, short to ground or voltage (HS-CAN +)
- Circuit 1828 (PK/LG) open, short to ground or voltage (HS-CAN -)
- Circuit 1827 (WH/LG) (HS-CAN +) and circuit 1828 (PK/LG) (HS-CAN -) shorted together
- ABS module
- Air suspension module/variable assist power steering (VAPS) module
- Fire suppression module (if equipped)
- Instrument cluster
- PCM