Pinpoint Test X: Abs (Anti-Lock Brake System) Module Communication Concern With The APIM (Sync Module)
- Refer to Horn/Cigar Lighter
for schematic and connector information.
Normal Operation and Fault Conditions
With the ignition ON, the APIM sends messages to the ABS module over the HS-CAN3 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 an APIM 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 APIM, refer to Network Message Charts .
When a drive mode is selected through the FCDIM, a message is sent to the APIM indicating the selected drive mode. The APIM sends a message out to other modules along the HS-CAN3 through the GWM indicating a specific drive mode has been selected. The other modules modify their operating parameters according to the drive mode selected.
DTC Fault Trigger Conditions
DTC Description Fault Trigger Condition ABS U0554:86 Invalid Data Received From Accessory Protocol Interface Module: Signal Invalid This DTC sets when ABS module receives an invalid signal from APIM. ABS U0253:00 Lost Communication With Accessory Protocol Interface Module: No Sub Type Information This DTC sets when the ABS module has not received any messages from the APIM in the allotted time. Possible Sources
- Wiring, terminals or connectors
- Network communication concern
- APIM
- X1 CHECK VEHICLE SPECIFICATION
- Check if vehicle is equipped with an APIM
Is the vehicle equipped with an APIM?
Yes GO to X2 No The DTC is set as the vehicle is not equipped with an APIM. Return the vehicle to the customer. - X2 CHECK CAN (CONTROLLER AREA NETWORK) DATA
- A DTC has been set which has the following description:
- Invalid Data Received From APIM Control 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 DTC's return?
Yes Invalid or Missing CAN Data From the APIM. Check the CAN bus and terminating resistor (60 ohm) at the OBD connector. Check CAN bus circuit. Check for other failures in the APIM Control 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. - A DTC has been set which has the following description: