Pinpoint Test C: One Or More Interior Courtesy Lamp Is Inoperative

Interior Lighting

Pinpoint Test C: One Or More Interior Courtesy Lamp Is Inoperative

Normal Operation

The Body Control Module (BCM) fuse 12 (15A) supplies power for the interior courtesy lamps (and the running board lamps if equipped). When the BCM (Body Control Module) receives the required input (such as an open door or request from the instrument panel dimmer switch), it provides voltage to the interior courtesy lamps.





This pinpoint test is intended to diagnose the following:

- Fuse

- Wiring, terminals or connectors

- Interior lamp

- BCM (Body Control Module)

PINPOINT TEST C : ONE OR MORE INTERIOR COURTESY LAMP IS INOPERATIVE

NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.

C1 CHECK THE OPERATION OF ALL THE INTERIOR COURTESY LAMPS

- Press and hold the instrument panel dimmer switch to the DOME LAMP ON (second detent up) position for 3 seconds.

Are all the interior courtesy lamps inoperative?

Yes
VERIFY the BCM (Body Control Module) fuse 12 (15A) is OK. If OK, GO to C4. If not OK, REFER to the Wiring Diagrams to identify the possible causes of the circuit short [1][2]Diagrams By Number. After the repair:

If no DTCs are present, TEST the system for normal operation.

If DTC U1000:00 is present, CLEAR the DTCs and REPEAT the self-test (required to enable the courtesy lamp output driver if DTC U1000:00 is present). TEST the system for normal operation.

If DTC U3000:49 is present, INSTALL a new BCM (Body Control Module). TEST the system for normal operation.
No
GO to C2.

C2 CHECK FOR VOLTAGE TO THE INTERIOR LAMP

- Turn the interior courtesy lamps off.

- Disconnect: Inoperative Interior Lamp.

- Press and hold the instrument panel dimmer switch to the DOME LAMP ON (second detent up) position for 3 seconds.

- Measure the voltage between the inoperative interior lamp, harness side and ground as follows:

Inoperative Lamp Connector-Pin Circuit Front interior lamp (without overhead console) C901-1 VLN33 (GY/VT) Front interior lamp (with overhead console) C929-2 VLN33 (GY/VT) Rear interior lamp C932-1 VLN33 (GY/VT)








Is the voltage greater than 10 volts?

Yes
GO to C3.
No
REPAIR circuit VLN33 (GY/VT) for an open. TEST the system for normal operation.

C3 CHECK THE INTERIOR LAMP GROUND CIRCUIT FOR AN OPEN

- Measure the voltage between the suspect interior lamp pins, harness side as follows:

Inoperative Lamp Connector-Pin Circuit Connector-Pin Circuit Front interior lamp (without overhead console) C901-1 VLN33 (GY/VT) C901-2 GD139 (BK/YE) Front interior lamp (with overhead console) C929-2 VLN33 (GY/VT) C929-1 GD139 (BK/YE) Rear interior lamp C932-1 VLN33 (GY/VT) C932-2 GD139 (BK/YE)







Is the voltage greater than 10 volts?

Yes
INSTALL a new interior lamp for the lamp in question. REFER to Interior Lamp . TEST the system for normal operation.
No
REPAIR circuit GD139 (BK/YE) for an open. TEST the system for normal operation.

C4 CHECK THE OPERATION OF THE DEMAND LIGHTING

- Operate the demand lighting function (such as the map light) on any interior lamp.

Does the interior lamp illuminate?

Yes
For vehicles that only have a single interior lamp, GO to C5.

For vehicles that have 2 interior lamps, GO to C6.
No
REPAIR circuit GD139 (BK/YE) for an open. TEST the system for normal operation.

C5 CHECK FOR VOLTAGE TO THE INTERIOR LAMP

- Press and hold the instrument panel dimmer switch to the DOME LAMP OFF (second detent down) position for 3 seconds.

- Disconnect: Front Interior Lamp.

- Ignition ON.

- Press and hold the instrument panel dimmer switch to the DOME LAMP ON (second detent up) position for 3 seconds.

- Measure the voltage between the interior lamp, harness side and ground as follows:

Inoperative Lamp Connector-Pin Circuit Front interior/map lamp (without overhead console) C901-1 VLN33 (GY/VT) Front interior/map lamp (with overhead console) C929-2 VLN33 (GY/VT)








Is the voltage greater than 10 volts?

Yes
INSTALL a new interior lamp. REFER to Interior Lamp . TEST the system for normal operation.
No
GO to C6.

C6 BYPASS THE BCM (Body Control Module)
NOTE: If the jumper wire fails, REFER to the Wiring Diagrams to identify the possible causes of the circuit short [1][2]Diagrams By Number. After the repair:

If no DTCs are present, test the system for normal operation.

If DTC U1000:00 is present, clear the DTCs and repeat the self-test (required to enable the courtesy lamp output driver if DTC U1000:00 is present). Test the system for normal operation.

If DTC U3000:49 is present, install a new BCM (Body Control Module). Test the system for normal operation.

- Connect: Front Interior Lamp.

- Disconnect: BCM (Body Control Module) C2280A.

- Connect a fused jumper wire between the BCM (Body Control Module) C2280A-1, circuit VLN33 (GY/VT), harness side and battery positive.






Do the courtesy lamps illuminate?

Yes
REMOVE the jumper wire. GO to C7.
No
REMOVE the jumper wire. REPAIR circuit VLN33 (GY/VT) for an open. TEST the system for normal operation.

C7 CHECK FOR CORRECT BCM (Body Control Module) OPERATION

- Disconnect all the BCM (Body Control Module) connectors.

- Check for:
- corrosion

- damaged pins

- pushed-out pins


- Connect all the BCM (Body Control Module) connectors and make sure they seat correctly.

- Operate the system and verify the concern is still present.

Is the concern still present?

Yes
INSTALL a new BCM (Body Control Module). TEST the system for normal operation.
No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.