Pinpoint Test B: The Courtesy Lamps Do Illuminate With the Liftgate Open

Interior Lighting

Pinpoint Test B: The Courtesy Lamps Do Illuminate With the Liftgate Open

Refer to Wiring Diagram Set 117, Remote Keyless Entry and Alarm for schematic and connector information. Diagrams By Number

Normal Operation

The Remote Function Actuator (RFA) module sends a voltage signal to the Liftgate/Trunk Module (LTM), which is routed to ground with the liftgate closed. When the liftgate is opened, the LTM opens the ground signal to the RFA module, indicating an open liftgate to the RFA module.

The RFA module broadcasts the liftgate ajar status to the Smart Junction Box (SJB) over the Medium Speed Controller Area Network (MS-CAN). Based on the ajar status, the SJB supplies voltage to the courtesy lamps.

- DTC B2721 (Liftgate/Decklid Ajar Output Short to Ground or Open) - a continuous and on-demand DTC that sets when the LTM detects a short to ground from the liftgate ajar circuit.

This pinpoint test is intended to diagnose the following:

- Wiring, terminals or connectors
- LTM
- RFA module

PINPOINT TEST B: THE COURTESY LAMPS DO NOT ILLUMINATE WITH THE LIFTGATE OPEN

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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B1 CHECK THE LTM

- Ignition OFF.
- Disconnect: LTM C4174b .
- Do the courtesy lamps illuminate?

Yes
GO to B4.

No
GO to B2.

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B2 CHECK THE LIFTGATE AJAR INPUT CIRCUIT FOR A SHORT TO GROUND

- Disconnect: RFA Module C2153e .
- Measure the resistance between the LTM C4174b-2, circuit CPL58 (GY/OG), harness side and ground.




- Is the resistance greater than 10,000 ohms?

Yes
GO to B3.

No
REPAIR the circuit. CLEAR the DTCs. TEST the system for normal operation.

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B3 CHECK FOR CORRECT RFA MODULE OPERATION

- Disconnect all the RFA module connectors.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect all the RFA 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 RFA module. REFER to Multifunction Electronic Modules Remote Function Actuator (RFA) 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.

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B4 CHECK FOR CORRECT LTM OPERATION

- Disconnect all the LTM connectors.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect all the LTM 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 LTM. REFER to Body Closures 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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