Pinpoint Test A: The Courtesy Lamps Do Not Illuminate With A Door Open

Interior Lighting

Pinpoint Test A: The Courtesy Lamps Do Not Illuminate With A Door Open

Normal Operation

The Body Control Module (BCM) sends a voltage signal to each door ajar switch, which is routed to ground when the door is closed (the door ajar switch is closed when the door is closed). When the door is opened, the signal to ground is interrupted indicating an open door to the BCM (Body Control Module).

When the BCM (Body Control Module) detects an open door, voltage is provided to the courtesy lamps.

NOTE: All the door ajar switches are integral to the door latch except for the rear door ajar switches on Super Cab vehicles. The rear door ajar switches on Super Cab vehicles are replaced independently of the door latch.

This pinpoint test is intended to diagnose the following:

- Wiring, terminals or connectors

- Door ajar switch

- BCM (Body Control Module)

PINPOINT TEST A : THE COURTESY LAMPS DO NOT ILLUMINATE WITH A DOOR OPEN
NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.

A1 CHECK THE OPERATION OF THE COURTESY LAMPS FROM THE INSTRUMENT PANEL DIMMER SWITCH

- Ignition OFF.

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

Do the interior courtesy lamps illuminate?

Yes
GO to A2.
No
GO to Pinpoint Test C. Pinpoint Test C: One Or More Interior Courtesy Lamp Is Inoperative

A2 CHECK THE DOOR AJAR SWITCH OPERATION

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

- Disconnect: Suspect Door Ajar Switch.

Do the courtesy lamps illuminate?

Yes
INSTALL a new door latch or ajar switch in question. TEST the system for normal operation.
No
GO to A3.

A3 CHECK THE DOOR AJAR SWITCH INPUT CIRCUIT FOR A SHORT TO GROUND

- Disconnect: BCM (Body Control Module) C2280C.

- For any door except a rear door on Super Cab vehicles, measure the resistance between the suspect door latch, harness side and ground as follows:

Location Connector-Pin Circuit LH front C525-5 CPL26 (GN/VT) RH front C609-5 CPL31 (WH) LH rear C705-5 CPL36 (GN) RH rear C805-5 CPL39 (YE)








- For a rear door on Super Cab vehicles, measure the resistance between the suspect door ajar switch, harness side and ground as follows:

Location Connector-Pin Circuit LH rear C715-2 CPL36 (GN) RH rear C820-2 CPL39 (YE)








Is the resistance greater than 10,000 ohms?

Yes
GO to A4.
No
REPAIR the circuit in question for a short to ground. TEST the system for normal operation.

A4 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.