Pinpoint Test AO: DTC U0100

Instrumentation, Message Center and Warning Chimes

Pinpoint Tests

Pinpoint Test AO: DTC U0100

Normal Operation
- DTC U0100 (Lost Communication With ECM/PCM) - sets in continuous memory if data messages received from the PCM over the High Speed Controller Area Network (HS-CAN) are missing for greater than 5 seconds.

NOTE: Once the Instrument Cluster (IC) sets DTC U0100, multiple gauges or indicators are likely to be inoperative in the IC. Other modules that require data from the IC all set communication DTCs and may also exhibit system function concerns.

This pinpoint test is intended to diagnose the following:

- PCM
- IC


PINPOINT TEST AO: DTC U0100

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AO1 VERIFY THAT THE SCAN TOOL CAN COMMUNICATE WITH THE PCM


- Connect the scan tool.
- Check that a vehicle session can be established using the scan tool.
- Can a vehicle session be established?

Yes
GO to AO2.

No
REFER to Module Communications Network Testing and Inspection to diagnose no communication with the PCM.

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AO2 CHECK THE IC CONTINUOUS MEMORY DTCs


- Ignition ON.
- Enter the following diagnostic mode on the scan tool: IC Self-Test .
- Clear the DTCs. Repeat the IC self-test.
- Is DTC U0100 retrieved again?

Yes
GO to AO3.

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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AO3 RETRIEVE THE RECORDED DTCs FROM THE IC SELF-TEST


- Check for recorded IC DTCs from the self-test.
- Is DTC B1317 or DTC B1318 recorded?

Yes
GO to Pinpoint Test AM (B1317) or GO to Pinpoint Test AN (B1318). Pinpoint Test AM: DTC B1317 Pinpoint Test AN: DTC B1318

No
GO to AO4.

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AO4 CHECK FOR DTC U0100 SET IN OTHER MODULES


- Ignition ON.
- Enter the following diagnostic mode on the scan tool: Self-Test .
- Retrieve the continuous memory DTCs from all modules.
- Is DTC U0100 set in the ABS module or the Restraints Control Module (RCM)?

Yes
INSTALL a new PCM. REFER to Electronic Engine Controls Service and Repair. CLEAR the DTCs. REPEAT the self-test.

No
INSTALL a new IC. REFER to Instrument Cluster (IC) Instrument Cluster (IC). TEST the system for normal operation.

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