Pinpoint Tests AV: DTC U0121:00

Instrumentation, Message Center and Warning Chimes


Pinpoint Tests


Pinpoint Test AV: 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 greater than 5 seconds. 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 AV: DTC U0121:00

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AV1 VERIFY THE CUSTOMER CONCERN


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

Yes
GO to AV2.

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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AV2 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 AV3.

No
REFER to Information Bus.

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AV3 RETRIEVE THE RECORDED DTCs FROM THE IPC SELF-TEST


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

Yes
Go To Pinpoint Test BB (U3003:16) or Go To Pinpoint Test BC (U3003:17). Pinpoint Tests BB: DTC U3003:16 Pinpoint Tests BC: DTC U3003:17

No
GO to AV4.

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AV4 RECHECK THE IPC DTCs


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

Yes
INSTALL a new ABS module. 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.

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