Pinpoint Test P: DTC U0140

Interior Lighting

Pinpoint Test P: DTC U0140

Normal Operation

- DTC U0140 (Lost Communication With Body Control Module (GEM (Generic Electronic Module))- set by the Interior Lighting Control Module (ILCM) when network messages are missing from the Smart Junction Box (SJB) for greater than 5 seconds. As more than one module receives these messages, all modules receiving a particular message should exhibit a symptom if the message is missing. For a complete list of all network messages, refer to Information Bus.

This pinpoint test is intended to diagnose the following:

- Communication network concern

- SJB (Smart Junction Box)

PINPOINT TEST P : DTC U0140

P1 VERIFY THE CUSTOM CONCERN

- Ignition ON.

- Verify that there is an observable symptom present.

Is an observable symptom present?

Yes
GO to P2.

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.

P2 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 P3.

No
REFER to Information Bus.

P3 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 P4.

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.

P4 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.