Pinpoint Tests AU: DTC U0121:00

Instrumentation, Message Center and Warning Chimes

Pinpoint Tests

Pinpoint Test AU: 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 Instrument Panel Cluster (IPC) if data messages received from the
ABS module over the High Speed Controller Area Network (HS-CAN) are missing. For a complete list of all network messages, refer to Information Bus.

This pinpoint test is intended to diagnose the following:

- ABS module
- IPC



PINPOINT TEST AU: DTC U0121:00

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AU1 VERIFY THE CUSTOMER CONCERN


- Ignition ON.
- Verify that there is an observable symptom present.
- Is an observable symptom present?

Yes
GO to AU2.

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

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AU2 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 AU3.

No
REFER to Information Bus.

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AU3 RETRIEVE THE RECORDED DTCs FROM THE IPC SELF-TEST


- Check for recorded DTCs from the IPC self-test.
- Is DTC U3003:16 or DTC U3003:17 recorded?

Yes
GO to Pinpoint Test BI (U3003:16) or GO to Pinpoint Test BJ (U3003:17). Pinpoint Tests BI: DTC U3003:16 Pinpoint Tests BJ: DTC U3003:17

No
GO to AU4.

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AU4 RECHECK THE IPC DTCs


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

- Clear the DTCs. Repeat the IPC self-test.
- Is DTC U0121:00 still present?

Yes
INSTALL a new ABS module. REFER to Antilock Brakes / Traction Control Systems. CLEAR the DTCs. REPEAT the IPC self-test.

If DTC U0121:00 is still present, INSTALL a new IPC. REFER to Instrument Panel Cluster (IPC) Instrument Panel Cluster (IPC). TEST the system for normal operation.

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.

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