Pinpoint Test B: The Courtesy Lamps Do Not Illuminate From The Instrument Panel Dimmer Switch

Interior Lighting

Pinpoint Test B: The Courtesy Lamps Do Not Illuminate From The Instrument Panel Dimmer Switch

Normal Operation

The Smart Junction Box (SJB) turns the courtesy lamps on and off by monitoring the dimmer switch input and the dome lamp request input circuits. When the instrument panel dimmer switch is pushed to the second detent up, the backlighting dim up circuit and the dome request circuit are both requested to indicate a request to turn the courtesy lamps on. When the instrument panel dimmer switch is pushed to the second detent down, the backlighting dim down circuit and the dome request circuit are both requested to indicate a request to turn the courtesy lamps off.

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 ILLUMINATE 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 OPERATION OF THE COURTESY LAMPS FROM THE DOOR

- Ignition OFF.

- Open any door and observe the interior courtesy lamps.

Are the interior courtesy lamps illuminated?

Yes
GO to B2.

No
GO to Pinpoint Test C. Pinpoint Test C: The Interior Courtesy Lamp(s) Are Inoperative

B2 CHECK THE DIMMABLE BACKLIGHTING ILLUMINATION

- Turn the headlamp switch to the PARKING LAMPS ON position.

- Monitor the instrument panel dimmable backlighting while pushing the instrument panel dimmer switch from full on to full off.

Does the instrument cluster and panel illumination intensity change with the instrument panel dimmer switch position?

Yes
GO to B3.

No
REFER to Instrument Panel, Gauges and Warning Indicators to continue diagnosis of the dimmable illumination.

B3 CHECK FOR A VOLTAGE SIGNAL TO THE INSTRUMENT PANEL DIMMER SWITCH

- Turn the headlamp switch to the OFF position.

- Disconnect: Instrument Panel Dimmer Switch C2065.

- Measure the voltage between the instrument panel dimmer switch C2065-2, circuit CLN28 (GN/BU), harness side and ground.





Is the voltage greater than 10 volts?

Yes
INSTALL a new instrument panel dimmer switch. TEST the system for normal operation.

No
GO to B4.

B4 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 B5.

No
REPAIR circuit CLN28 (GN/BU) for an open. TEST the system for normal operation.

B5 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.