Test B: The Driver Seat Module (DSM) Does Not Respond To The Diagnostic Tool

PINPOINT TEST B: THE DRIVER SEAT MODULE (DSM) DOES NOT RESPOND TO THE DIAGNOSTIC TOOL

B1-B2:

B3:

Normal Operation
The DSM communicates with the diagnostic tool through the universal asynchronous receiver-transmitter (UART)-based protocol (UBP) network, circuit 2077 (PK/LB). If circuit 2077 (PK/LB) becomes open or shorted to ground, communications to that module are not possible. Check circuit 2077 (PK/LB) between the DSM C341c and the data link connector (DLC) C251. The total resistance values must not be more than 5 ohms. If the resistance is more than 5 ohms, there is an open in circuit 2077 (PK/LB), damage to the DLC C251, damage to the DSM C341c, or a problem in the in-line connectors.

Possible Causes
- UBP circuit 2077 (PK/LB) open
- DSM C341c
- DSM