Pinpoint Tests BB: DTC U0140

Instrumentation, Message Center and Warning Chimes

Pinpoint Tests

Pinpoint Test BB: DTC U0140

Normal Operation
- DTC U0140 (Lost Communication With Body Control Module [GEM]) - sets in continuous memory in the Instrument Cluster (IC) if data messages received from the Smart Junction Box (SJB) over the Medium Speed Controller Area Network (MS-CAN) are missing. For a complete list of all network messages, refer to Information Bus.

This pinpoint test is intended to diagnose the following:

- SJB
- IC




PINPOINT TEST BB: DTC U0140

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BB1 VERIFY THE CUSTOMER CONCERN



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

Yes
GO to BB2.

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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BB2 CHECK THE COMMUNICATION NETWORK



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

Yes
GO to BB3.

No
REFER to Information Bus.

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BB3 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 AR (B1317) or GO to Pinpoint Test AS (B1318). Pinpoint Tests AR: DTC B1317 Pinpoint Tests AS: DTC B1318

No
GO to BB4.

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BB4 RECHECK THE IC DTCs



- Clear the DTCs. Repeat the IC self-test.
- Is DTC U0140 still present?

Yes
GO to BB5.

No
The system is operating correctly at this time. The DTC may have been set due to high network traffic.

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BB5 CHECK FOR DTC U0140 SET IN OTHER MODULES



- Clear all DTCs.
- Ignition OFF.
- Ignition ON.
- Wait 10 seconds.
- Enter the following diagnostic mode on the scan tool: Self-Test .
- Retrieve the continuous memory DTCs from all modules.
- Is DTC U0140 set in the Audio Control Module (ACM) or HVAC module?

Yes
INSTALL a new SJB. REFER to Body Control Systems. 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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