Pinpoint Test O: DTC U0140

Interior Lighting

Pinpoint Test O: DTC U0140

Normal Operation

- DTC U0140 (Lost Communication With Body Control Module (GEM (Generic Electronic Module))- sets in the Interior Lighting Control Module (ILCM) if data messages are missing or not received from the Smart Junction Box (SJB) over the Medium Speed Controller Area Network (MS-CAN). For a complete list of all network messages, refer to Information Bus.

This pinpoint test is intended to diagnose the following:

- Wiring, terminals or connectors

- SJB (Smart Junction Box)

PINPOINT TEST O : DTC U0140

O1 VERIFY THE CUSTOM CONCERN

- Ignition ON.

- Verify that there is an observable symptom present.

Is an observable symptom present?

Yes
GO to O2.

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.

O2 CHECK THE COMMUNICATION NETWORK

- Enter the following diagnostic mode on the scan tool: Network Test.

- Carry out the network test.

Does the SJB (Smart Junction Box) pass the network test?

Yes
GO to O3.

No
REFER to Information Bus.

O3 RECHECK THE ILCM (Interior Lighting Control Module) DTCs

- Enter the following diagnostic mode on the scan tool: ILCM (Interior Lighting Control Module) Self-Test.

- Clear the DTCs and repeat the ILCM (Interior Lighting Control Module) self-test.

Is DTC U0140 still present?

Yes
GO to O4.

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.

O4 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 Driver Seat Module (DSM) or the Driver Door Module (DDM)?

Yes
INSTALL a new SJB (Smart Junction Box). CLEAR all continuous DTCs. REPEAT the self-test.

No
INSTALL a new ILCM (Interior Lighting Control Module). REFER to Interior Lighting Control Module (ILCM) . TEST the system for normal operation.