Pinpoint Test As: Abs (Anti-Lock Brake System) Module Communication Concern With The ATCM (All Terrain Control Module)

Refer to Horn/Cigar Lighter for schematic and connector information.

Normal Operation and Fault Conditions

With the ignition ON, the ATCM module sends messages to the ABS module over the HS-CAN1 through the GWM. If the ABS module does not receive these messages within the allotted time frame or if the messages contain invalid data, the module sets a DTC. This can be due to a ATCM module failure, a circuit failure on the network or an excessive load on the network. For information on the messages sent to the ABS module by the ATCM module, refer to Network Message Charts .

DTC Fault Trigger Conditions

DTC	Description	Fault Trigger Condition
ABS U0138:00	Lost Communication with All Terrain Control Module: No Sub Type Information	This DTC sets when the ABS module cannot communicate with the ATCM.
ABS U0138:86	Lost Communication with All Terrain Control Module: Signal Invalid	This DTC sets when the ABS module receives any invalid messages from the ATCM within the allowed time.
ABS U0138:87	Lost Communication with All Terrain Control Module: Missing Message	This DTC sets when the ABS module does not receive any messages from the ATCM within the allowed time.

Possible Sources

Network communication concern
GWM
ATCM module

AS1 CHECK CAN (CONTROLLER AREA NETWORK) DATA

A DTC has been set which has the following description:
- Invalid Data Received From ATCM module

Ignition ON.

Clear the ABS DTCs.

Ignition OFF.

Ignition ON.

Wait at least 1 minute.

Using a diagnostic scan tool, retrieve all DTCs from the ABS module. NOTE: DTCs may be displayed from previous diagnostic actions.

Did the DTCs return?

Yes	Invalid or Missing CAN Data From the ATCM. Check the CAN bus and terminating resistor (60 ohm) at the OBD connector. Check CAN bus circuit. Check for other failures in the ATCM module. Notice: Do not replace the ABS module.

No	Return the vehicle to the customer. If the fault reoccurs inform the customer to note any relevant conditions at the time of the fault. The test is now exiting.