Pinpoint Tests AT: DTC U0100

Instrumentation, Message Center and Warning Chimes

Pinpoint Tests

Pinpoint Test AT: DTC U0100

Normal Operation
- DTC U0100 (Lost Communication With ECM/PCM) - sets in the Instrument Cluster (IC) if data messages received from the PCM over the High Speed Controller Area Network (HS-CAN) are missing for 5 seconds or longer.

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

This pinpoint test is intended to diagnose the following:

- PCM
- IC



PINPOINT TEST AT: DTC U0100

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AT1 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 AT2.

No
REFER to Information Bus to diagnose no communication with the PCM.

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AT2 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 AT3.

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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AT3 RETRIEVE THE RECORDED DTCs FROM THE IC SELF-TEST


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

Yes
Go To Pinpoint Test AP (B1317) or Go To Pinpoint Test AQ (B1318). Pinpoint Tests AP: DTC B1317 Pinpoint Tests AQ: DTC B1318

No
GO to AT4.

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AT4 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. 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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