Test B: The Anti-Lock Brake System (ABS) Module Does Not Respond to the Diagnostic Tool

PINPOINT TEST B: THE ANTI-LOCK BRAKE SYSTEM (ABS) MODULE DOES NOT RESPOND TO THE DIAGNOSTIC TOOL

B1:

B2-B3:

Normal Operation
The ABS module communicates with the diagnostic tool through the high speed controller area network (CAN), circuits 1908 (WH) and 1909 (BK). The high speed CAN remains operational with the severing of one of the high speed CAN circuits or if the data minus circuit is shorted to ground. Communication may also continue if one of the termination resistors is lost. The high speed CAN does not remain operational if the data plus circuit is shorted to ground or shorted to voltage. The high speed CAN also does not remain operational if the data minus circuit is shorted to voltage. Check circuits 1908 (WH) and 1909 (BK) between the ABS module C135 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 one of the high speed CAN circuits, damage to the DLC C251, damage to the ABS module C135, or a problem in an in-line connector.

Possible Causes
- high speed CAN circuit 1908 (WH) or 1909 (BK) short to ground or open
- DLC C251
- ABS module C135
- ABS module