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Pinpoint Test K: The Ambient Lighting Is Inoperative




Interior Lighting

Pinpoint Tests

Pinpoint Test K: The Ambient Lighting Is Inoperative

Refer to Wiring Diagram Set 89, Interior Lamps for schematic and connector information. Diagrams By Number

Normal Operation

The Interior Lighting Control Module (ILCM) supplies voltage and ground to the LEDs located in the floor console cup holders, storage tray, storage bin and the front and rear footwells.

The ILCM turns the ambient lighting on to a preset color and brightness setting when a door is open or the illuminated entry feature is active. The ambient lighting is also active when the ignition is in run and the parking lamps are on.

The ambient lighting switch is used to cycle through the 5 color combinations or to turn the ambient lighting feature off. There are 3 different color (red, blue and green) LEDs housed within each LED assembly.

The ILCM sends a voltage signal to the ambient lighting switch. When the ambient lighting switch (a momentary contact switch) is pressed, the voltage signal is routed to ground, indicating a request for the module to cycle the ambient lighting to the next color setting or to turn the ambient lighting off.

The color and brightness settings can only be changed when the ignition is in run, the parking lamps are on and all the doors are closed.

- DTC B2B18 (Ambient Light Switch Input Fault) - a continuous and on-demand DTC that sets when the ILCM detects a short to ground from the ambient lighting switch input circuit.

This pinpoint test is intended to diagnose the following:

- Wiring, terminals or connectors
- Ambient lighting switch
- ILCM

PINPOINT TEST K: THE AMBIENT LIGHTING IS 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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K1 CHECK FOR COMMUNICATION TO THE ILCM

- Enter the following diagnostic mode on the scan tool: ILCM Network Test.
- Carry out the network test using the scan tool.
- Does the scan tool communicate with the ILCM?

Yes
GO to K2.

No
REFER to Module Communications Network Testing and Inspection.

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K2 CHECK THE INPUT FROM THE AMBIENT LIGHTING SWITCH

- Enter the following diagnostic mode on the scan tool: ILCM DataLogger.
- While pressing and releasing the ambient lighting switch, monitor the ILCM ambient lighting switch PID (AmbiColor).
- Does the PID read active with the switch pressed and idle with the switch released?

Yes
GO to K8.

No
If the PID always reads active, GO to K3. If the PID always reads idle, GO to K5.

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K3 CHECK THE AMBIENT LIGHTING SWITCH FOR A SHORT TO GROUND

- Disconnect: Ambient Lighting Switch C3348.
- Enter the following diagnostic mode on the scan tool: ILCM DataLogger.
- Monitor the ILCM ambient lighting switch PID (AmbiColor).
- Does the PID still read active?

Yes
GO to K4.

No
INSTALL a new ambient lighting switch. REFER to Ambient Lighting Switch Service and Repair. TEST the system for normal operation.

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K4 CHECK THE AMBIENT LIGHTING SWITCH INPUT CIRCUIT FOR A SHORT TO GROUND

- Ignition OFF.
- Disconnect: ILCM C3498.
- Measure the resistance between the ILCM C3498-8, circuit CPL60 (WH/BN), harness side and ground.




- Is the resistance greater than 10,000 ohms?

Yes
GO to K9.

No
REPAIR circuit CPL60 (WH/BN) for a short to ground. TEST the system for normal operation.

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K5 BYPASS THE AMBIENT LIGHTING SWITCH

- Ignition OFF.
- Disconnect: Ambient Lighting Switch C3348.
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: ILCM DataLogger.
- Monitor the ILCM ambient lighting switch PID (AmbiColor).
- Connect a fused jumper wire between the ambient lighting switch C3348-2, circuit CPL60 (WH/BN), harness side and ground.




- Does the PID read active?

Yes
REMOVE the jumper wire. GO to K6.

No
REMOVE the jumper wire. GO to K7.

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K6 CHECK THE AMBIENT LIGHTING SWITCH GROUND CIRCUIT FOR AN OPEN

- Enter the following diagnostic mode on the scan tool: ILCM DataLogger.
- Monitor the ILCM ambient lighting switch PID (AmbiColor).
- Connect a fused jumper wire between the ambient lighting switch C3348-2, circuit CLN60 (WH/BN), harness side and the ambient lighting switch C3348-7, circuit GD908 (BK), harness side.




- Does the PID read active?

Yes
REMOVE the jumper wire. INSTALL a new ambient lighting switch. REFER to Ambient Lighting Switch Service and Repair. TEST the system for normal operation.

No
REMOVE the jumper wire. REPAIR circuit GD908 (BK) for an open. TEST the system for normal operation.

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K7 CHECK THE AMBIENT LIGHTING SWITCH INPUT CIRCUIT FOR AN OPEN

- Ignition OFF.
- Disconnect: ILCM C3498.
- Measure the resistance between the ILCM C3498-8, circuit CLN60 (WH/BN), harness side and the ambient lighting switch C3348-2, circuit CLN60 (WH/BN), harness side.




- Is the resistance less than 5 ohms?

Yes
GO to K9.

No
REPAIR circuit CLN60 (WH/BN) for an open. TEST the system for normal operation.

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K8 CHECK THE AMBIENT LIGHTING RETURN CIRCUIT

- Ignition OFF.
- Check the diode circuits between the ILCM, harness side as follows:








- Does the meter indicate the circuit is good?

Yes
GO to K9.

No
REPAIR circuit RLN44 (BU) for an open. TEST the system for normal operation.

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K9 CHECK FOR CORRECT ILCM OPERATION

- Disconnect the ILCM connector.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect the ILCM connector and make sure it seats correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?

Yes
INSTALL a new ILCM. REFER to Interior Lighting Control Module (ILCM) Service and Repair. 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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