Test B: The Transmission Control Module (TCM) Does Not Respond To The Scan Tool

PINPOINT TEST B: THE TRANSMISSION CONTROL MODULE (TCM) DOES NOT RESPOND TO THE SCAN TOOL

B1:

B1-B3:

B3-B4:

Normal Operation
The TCM 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 TCM. The TCM shares the HS-CAN network with the powertrain control module (PCM), 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. Voltage for the TCM is provided by circuits CBB73 (WH/BN) and SBB37 (GY/RD). Circuit GD113 (BK/YE) provides ground.

DTC U0101 - sets in a module which had attempted to communicate with the TCM and failed.

Possible Causes
- Fuse
- Circuit CBB73 (WH/BN) open
- Circuit GD113 (BK/YE) open
- Circuit SBB37 (GY/RD) open
- Circuit VDB04 (WH/BU) open (HS-CAN +)
- Circuit VDB05 (WH) open (HS-CAN -)
- TCM