Pinpoint Test Q: DTC U0140

Information and Entertainment System

Pinpoint Tests

Pinpoint Test Q: DTC U0140

Normal Operation
- DTC U0140 (Lost Communication With Body Control Module [GEM]) - set by the Audio Control Module (ACM) if the illumination dimmer level message is not received from the Smart Junction Box (SJB) over the Medium Speed Controller Area Network (MS-CAN) for greater than 5 seconds. The SJB also sends this signal to other modules with network-based illumination. Those other modules should also exhibit incorrect illumination operation if the illumination dimmer level signal is missing.

This pinpoint test is intended to diagnose the following:
- Module communication
- SJB
- ACM



PINPOINT TEST Q: DTC U0140

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Q1 VERIFY THE OPERATION OF THE PANEL ILLUMINATION


- Ignition ON.
- Turn the parking lamps on.
- Cycle the dimmer switch through all positions.
- Does the panel illumination operate correctly for all components with network-based illumination (including the ACM)?

Yes
The system is operating correctly at this time. The DTC may have been set due to high network traffic or intermittent fault condition.

No
GO to Q2.

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Q2 CHECK THE COMMUNICATION NETWORK


- Turn the parking lamps off.
- Carry out the network test using the scan tool.
- Does the SJB pass the network test?

Yes
GO to Q3.

No
REFER to Information Bus.

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Q3 RETRIEVE THE RECORDED DTCs FROM THE ACM SELF-TEST


- Check for recorded ACM DTCs from the self-test.
- Is DTC B1318 recorded?

Yes
Go To Pinpoint Test O. Pinpoint Test O: DTC B1318

No
GO to Q4.

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Q4 RECHECK THE ACM DTCs


NOTE: If new modules were installed prior to the DTC being set, the module configuration may be incorrectly set during Programmable Module Installation (PMI) or the PMI may not have been carried out.

- Clear the ACM continuous DTCs.
- Ignition OFF.
- Ignition ON.
- Wait 10 seconds.
- Retrieve the ACM continuous DTCs.
- Is DTC U0140 still present?

Yes
GO to Q5.

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

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Q5 CHECK FOR DTC U0140 SET IN OTHER MODULES


- Clear all DTCs from all modules.
- Ignition OFF.
- Ignition ON.
- Wait 10 seconds.
- Retrieve the continuous memory DTCs from all modules.
- Is DTC U0140 set in any modules other than the ACM?

Yes
INSTALL a new SJB. CLEAR the ACM DTCs. REPEAT the self-test.

No
INSTALL a new ACM. REFER to Audio Control Module (ACM) Removal and Replacement. TEST the system for normal operation.

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