Pinpoint Test A: The Courtesy Lamps Are Inoperative
Interior Lighting
Pinpoint Test A: The Courtesy Lamps Are Inoperative
Refer to Wiring Diagram Set 89, Interior Lamps for schematic and connector information. Diagrams By Number
Normal Operation
The Central Junction Box (CJB) fuse 18 (15A) provides power to the Lighting Control Module (LCM). The Driver Door Module (DDM) monitors the door ajar switches. The door ajar switches provide a path to ground, indicating an open door. The DDM then signals the LCM to supply power to the courtesy lamps. The LCM monitors the instrument panel dimmer switch input to determine the dimmable lighting level.
This pinpoint test is intended to diagnose the following:
- Fuse
- Wiring, terminals or connectors
- LCM
PINPOINT TEST A: THE COURTESY LAMPS ARE INOPERATIVE
NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.
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A1 CHECK THE DRIVER DOOR AJAR INPUT
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: DDM DataLogger.
- Monitor the DDM driver door ajar PID (D_DR_SW) while opening and closing the driver door.
- Does the DDM PID value agree with the door positions?
Yes
GO to A2.
No
GO to Pinpoint Test D. Pinpoint Test D: The Courtesy Lamps Do Not Turn On With One Door Open
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A2 CHECK THE PASSENGER DOOR AJAR INPUTS
- Monitor the DDM passenger door ajar PID (P_DR_SW) while opening and closing the LH rear, RH front and RH rear doors.
- Do the DDM PID values agree with the door positions?
Yes
GO to A3.
No
GO to Pinpoint Test D. Pinpoint Test D: The Courtesy Lamps Do Not Turn On With One Door Open
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A3 CHECK THE HEADLAMP DIMMER SWITCH INPUT
- Operate the courtesy lamps using the dimmer control switch.
- Do the courtesy lamps illuminate?
Yes
GO to A4.
No
GO to Pinpoint Test I. Pinpoint Test I: The Courtesy Lamps Are Inoperative - From The Instrument Panel Dimmer Switch
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A4 CHECK THE LCM FOR CORRECT OUTPUTS
- Enter the following diagnostic mode on the scan tool: LCM DataLogger.
- Trigger the LCM (COURTESY) active command on.
- Do the courtesy lamps illuminate?
Yes
GO to A7.
No
GO to A5.
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A5 CHECK THE LCM VOLTAGE SUPPLY CIRCUIT FOR AN OPEN
- Ignition OFF.
- Disconnect: LCM C2145c.
- Measure the voltage between the LCM C2145c-4, circuit 54 (LG/YE), harness side and ground.
- Is the voltage greater than 10 volts?
Yes
GO to A6.
No
VERIFY the CJB fuse 18 (15A) is OK. If OK, REPAIR circuit 54 (LG/YE) for an open. TEST the system for normal operation. If not OK, REFER to the Wiring Diagrams to identify the possible causes of the circuit short. Diagrams By Number
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A6 CHECK THE COURTESY LAMP OUTPUT CIRCUIT FOR AN OPEN
- NOTE: If the fuse fails, repair circuit 53 (BK/LB) for a short to ground.
- Connect a fused jumper wire between the LCM C2145c-4, circuit 54 (LG/YE), harness side and the LCM C2145c-5, circuit 53 (BK/LB), harness side.
- Do the courtesy lamps illuminate?
Yes
REMOVE the jumper wire. GO to A7.
No
REMOVE the jumper wire. REPAIR circuit 53 (BK/LB) for an open. TEST the system for normal operation.
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A7 CHECK FOR CORRECT LCM OPERATION
- Disconnect all the LCM connectors.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect all the LCM 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 LCM. REFER to Multifunction Electronic Modules Lighting Control Module (LCM). 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.
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