Pinpoint Test R: Abs (Anti-Lock Brake System) Module Communication Issue With The GSM (Gear Shift Module)

Refer to HORN/CIGAR LIGHTER for schematic and connector information.

Normal Operation and Fault Conditions

With the ignition ON, the GSM 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 GSM 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 GSM, refer to the Network Message Chart in Network Message Charts .

DTC Fault Trigger Conditions

DTC	Description	Fault Trigger Condition
ABS U0404:86	Invalid Data Received from Gear Shift Control Module A: Signal Invalid	This DTC sets when the ABS module receives invalid data from GSM.
ABS U0103:00	Lost Communication With Gear Shift Control Module A: No Sub Type Information	This DTC sets when the ABS module does not receive any messages from the GSM within the allowed time.

Possible Sources

Network communication concern
GWM
GSM

R1 CHECK DATA FROM GSM (GEAR SHIFT MODULE)

A DTC has been set which has the following description:
- Invalid Data Received From the GSM.

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 GSM. Check the CAN bus and terminating resistor (60 ohm) at the OBD connector. Check CAN bus circuit. Check for other failures in the GSM. 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.