Body Control Systems

Remote Function Actuator (RFA) Module

Pinpoint Test L: DTC U0121:00

Normal Operation

- DTC U0121:00 (Lost Communication With Anti-Lock Brake System (ABS) Control Module: No Sub Type Information)- sets in the Remote Function Actuator (RFA) module if data messages received from the ABS module are missing. For a complete list of all network messages, refer to Information Bus.

This pinpoint test is intended to diagnose the following:

- Communication network concern

- ABS module

- RFA (Remote Function Actuator) module

PINPOINT TEST L : DTC U0121:00

L1 VERIFY THE CUSTOMER CONCERN

- Ignition ON.

- Verify that there is an observable symptom present.

Is an observable symptom present?

Yes
GO to L2.

No
The system is operating correctly at this time. The DTC may have been set due to high network traffic or an intermittent fault condition.

L2 CHECK THE COMMUNICATION NETWORK

- Ignition ON.

- Enter the following diagnostic mode on the scan tool: Network Test.

- Carry out the network test.

Does the ABS module pass the network test?

Yes
GO to L3.

No
REFER to Information Bus, The ABS Module Does Not Respond To The Scan Tool Pinpoint Test B: The ABS Module Does Not Respond To The Scan Tool.

L3 RETRIEVE THE RECORDED DTCs FROM THE RFA (Remote Function Actuator) MODULE SELF-TEST

- Check for recorded RFA (Remote Function Actuator) module DTCs from the self-test.

Is DTC U3003:16 or DTC U3003:17 recorded?

Yes
For DTC U3003:16, GO to Pinpoint Test O Pinpoint Test O: DTC U3003:16.

For DTC U3003:17, GO to Pinpoint Test P Pinpoint Test P: DTC U3003:17.

No
GO to L4

L4 CHECK FOR DTCs U3003:16 AND U3003:17 FROM THE ABS MODULE SELF-TEST

- Retrieve the continuous memory DTCs from the ABS module.

Is DTC U3003:16 or DTC U3003:17 recorded?

Yes
REFER to Antilock Brakes / Traction Control Systems.

No
GO to L5.

L5 RECHECK THE RFA (Remote Function Actuator) MODULE DTCs

NOTE: If new modules were installed prior to the DTC being set, the module configuration may be incorrectly set during Programmable Module Installation (PMI) or the PMI (Programmable Module Installation) may not have been carried out.

- Clear the DTCs. Repeat the RFA (Remote Function Actuator) module self-test.

Is DTC U0121:00 still present?

Yes
GO to L6.

No
The system is operating correctly at this time. The DTC may have been set due to high network traffic or an intermittent fault condition.

L6 CHECK FOR DTC U0121:00 OR DTC U0121 SET IN OTHER MODULES

- Clear the DTCs.

- Ignition OFF.

- Ignition ON.

- Wait 10 seconds.

- Enter the following diagnostic mode on the scan tool: Self-Test.

- Retrieve the continuous memory DTCs from all modules.

Is DTC U0121:00 OR DTC U0121 set in any other module?

Yes
INSTALL a new ABS module. CLEAR the DTCs. REPEAT the self-test.

No
INSTALL a new RFA (Remote Function Actuator) module. REFER to Remote Function Actuator (RFA) Module Remote Function Actuator (RFA) Module. TEST the system for normal operation.