Pinpoint Test B: The Courtesy Lamps Do Not Turn On From The Instrument Panel Dimmer Switch
Interior Lighting
Pinpoint Test B: The Courtesy Lamps Do Not Turn On From The Instrument Panel Dimmer Switch
Normal Operation
The Smart Junction Box (SJB) sends a voltage signal to the instrument panel dimmer switch to determine if the courtesy lamps are requested. When the instrument panel dimmer switch is rotated to the DOME LAMP position, the voltage signal is routed to ground indicating a request to the courtesy lamps. When the request is detected, the SJB (Smart Junction Box) supplies voltage to the courtesy lamps.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Instrument panel dimmer switch
- SJB (Smart Junction Box)
PINPOINT TEST B : THE COURTESY LAMPS DO NOT TURN ON FROM THE INSTRUMENT PANEL DIMMER SWITCH
NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.
B1 CHECK THE DIMMABLE BACKLIGHTING OPERATION
- Place the headlamp switch in the PARKING LAMPS ON position.
- Monitor the instrument panel dimmable backlighting while rotating the instrument panel dimmer switch from full on to full off.
Does the dimmable backlighting intensity change with the instrument panel dimmer switch position?
Yes
For stripped chassis vehicles, GO to B2.
For all other vehicles, GO to B3.
No
REFER to Instrument Panel, Gauges and Warning Indicators.
B2 CHECK THE INSTRUMENT PANEL DIMMER SWITCH INPUT
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: SJB (Smart Junction Box) DataLogger.
- Monitor the SJB (Smart Junction Box) instrument panel dimmer switch PID (DOMELM_SW) while rotating the instrument panel dimmer switch in and out of the DOME LAMP position.
Does the PID agree with the instrument panel dimmer switch position?
Yes
GO to Pinpoint Test C. Pinpoint Test C: The Interior Courtesy Lamp(s) Are Inoperative
No
GO to B4.
B3 CHECK COURTESY LAMP OPERATION FROM A DOOR
- Open any door and observe the courtesy lamps.
Do the courtesy lamps illuminate?
Yes
GO to B4.
No
GO to Pinpoint Test C. Pinpoint Test C: The Interior Courtesy Lamp(s) Are Inoperative
B4 BYPASS THE INSTRUMENT PANEL DIMMER SWITCH
- Ignition OFF.
- Disconnect: Instrument Panel Dimmer Switch C2065.
- Connect a fused jumper wire between the instrument panel dimmer switch C2065-2, circuit CLN28 (GN/BU), harness side and the instrument panel dimmer switch C2065-4, circuit RLN29 (WH/OG), harness side.
Do the courtesy lamps illuminate?
Yes
REMOVE the jumper wire. INSTALL a new instrument panel dimmer switch. TEST the system for normal operation.
No
REMOVE the jumper wire. GO to B5.
B5 CHECK THE DOME LAMP REQUEST INPUT CIRCUIT FOR AN OPEN
- Disconnect: SJB (Smart Junction Box) C2280B.
- Measure the resistance between the SJB (Smart Junction Box) C2280B-51, circuit CLN28 (GN/BU), harness side and the instrument panel dimmer switch C2065-2, circuit CLN28 (GN/BU), harness side.
Is the resistance less than 5 ohms?
Yes
GO to B6.
No
REPAIR circuit CLN28 (GN/BU) for an open. TEST the system for normal operation.
B6 CHECK FOR CORRECT SJB (Smart Junction Box) OPERATION
- Disconnect all the SJB (Smart Junction Box) connectors.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect all the SJB (Smart Junction Box) 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 SJB (Smart Junction Box). 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.