Pinpoint Test K: DTC U0101

Anti-Lock Control

Pinpoint Tests

Pinpoint Test K: DTC U0101

Normal Operation

- DTC U0101 (Lost Communication With Transmission Control Module (TCM)) - sets in continuous and on-demand memory in the ABS module if data messages received such as the transmission range info, from the TCM are missing for more than 5 seconds. For a complete list of all network messages, refer to Module Communications Network Testing and Inspection

This pinpoint test is intended to diagnose the following:
- Communication network concern
- TCM
- ABS module

PINPOINT TEST K: DTC U0101

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K1 VERIFY THE CUSTOMER CONCERN


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

Yes
GO to K2.

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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K2 CHECK THE COMMUNICATION NETWORK


- Ignition ON.
- Enter the following diagnostic mode on the scan tool: Network Test.
- Carry out the network test.
- Does the TCM pass the network test?

Yes
GO to K3.

No
REFER to Module Communications Network Testing and Inspection.

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K3 RECHECK THE ABS MODULE DTCs


- Clear the DTCs.
- Wait 10 seconds.
- Repeat the ABS module self-test.
- Is DTC U0101 still present?

Yes
GO to K4.

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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K4 CHECK FOR DTC U0101 SET IN OTHER MODULES


- Clear the DTCs.
- Ignition OFF.
- Ignition ON.
- Wait 10 seconds.
- Enter the following diagnostic mode on the scan tool: Retrieve All CMDTCs.
- Retrieve the continuous memory DTCs from all modules.
- Is DTC U0101 set in more than one module?

Yes
INSTALL a new TCM. REFER to Transmission Service Components - Exploded View, External Components in Automatic Transaxle/Transmission - 6R80 Mechatronic Assembly. CLEAR the DTCs. REPEAT the self-test.

No
INSTALL a new ABS module. REFER to Anti-Lock Brake System (ABS) Module Service and Repair. TEST the system for normal operation.

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