Pinpoint Tests BG: DTC U0164

Instrumentation, Message Center and Warning Chimes

Pinpoint Tests

Pinpoint Test BG: DTC U0164

Normal Operation

- DTC U0164 (Lost Communication With HVAC Control Module [(EATC]) - sets if data messages received from the HVAC module over the Medium Speed Controller Area Network (MS-CAN) are missing. 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:

- HVAC module
- IC


PINPOINT TEST BG: DTC U0164

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BG1 VERIFY THE CUSTOMER CONCERN

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

Yes
GO to BG2.

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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BG2 CHECK THE COMMUNICATION NETWORK

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

Yes
GO to BG3.

No
REFER to Module Communications Network Testing and Inspection.

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BG3 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 AS (B1317) or GO to Pinpoint Test AT (B1318). Pinpoint Tests AS: DTC B1317 Pinpoint Tests AT: DTC B1318

No
GO to BG4.

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BG4 RECHECK THE IC 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 IC self-test.
- Is DTC U0164 still present?

Yes
INSTALL a new HVAC module. CLEAR the DTCs. REPEAT the IC self-test.

If DTC U0164 is still present, INSTALL a new IC. REFER to Instrument Cluster (IC) Instrument Cluster (IC). 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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