Pinpoint Tests BC: DTC U0140
Instrumentation, Message Center and Warning Chimes
Pinpoint Tests
Pinpoint Test BC: 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 Module Communications Network Testing and Inspection.
This pinpoint test is intended to diagnose the following:
- SJB
- IC
PINPOINT TEST BC: DTC U0140
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BC1 VERIFY THE CUSTOMER CONCERN
- Ignition ON.
- Verify that there is an observable symptom present.
- Is an observable symptom present?
Yes
GO to BC2.
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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BC2 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 BC3.
No
REFER to Module Communications Network Testing and Inspection.
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BC3 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 BC4.
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BC4 RECHECK THE IC DTCs
- Clear the DTCs. Repeat the IC self-test.
- Is DTC U0140 still present?
Yes
GO to BC5.
No
The system is operating correctly at this time. The DTC may have been set due to high network traffic.
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BC5 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 Multifunction Electronic Modules 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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