Pinpoint Test AU: Abs (Anti-Lock Brake System) Module Communication Concern With The RCM (Restraints Control Module)

Refer to VEHICLE DYNAMIC SYSTEMS for schematic and connector information.

Normal Operation and Fault Conditions

With the ignition ON, the RCM module sends messages to the ABS module over the HS-CAN2 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 RCM 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 RCM module, refer to the Network Message Chart in Network Message Charts .

DTC Fault Trigger Conditions

DTC	Description	Fault Trigger Condition
ABS U0452:41	Invalid Data Received From Restraints Control Module: General Checksum Failure	Sets when the messages received from the RCM indicate invalid information or indicate a fault.

Possible Sources

Network communication concern
GWM
RCM module

AU1 CHECK CAN (CONTROLLER AREA NETWORK) DATA

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

Ignition ON.

Clear the ABSDTC's.

Ignition OFF.

Ignition ON.

Wait at least 1 minute.

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

Did the DTC's return?

Yes	Invalid or Missing CAN Data From the RCM. Check the CAN bus and terminating resistor (60 ohm) at the OBD connector. Check CAN bus circuit. Check for other failures in the RCM 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.