Pinpoint Test B: The Courtesy Lamps Do Not Illuminate With the Liftgate Open

Interior Lighting

Pinpoint Tests

Pinpoint Test B: The Courtesy Lamps Do Not 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

When the liftgate is opened, the liftgate ajar switch (or Liftgate/Trunk Module (LTM), if equipped) opens the ground signal to the Smart Junction Box (SJB). The SJB monitors the liftgate ajar circuit, and based on the ajar status, 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 input circuit to the SJB.

This pinpoint test is intended to diagnose the following:

- Wiring, terminals or connectors
- Liftgate ajar switch (part of the liftgate latch)
- LTM
- SJB


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 OR THE LIFTGATE LATCH


- Ignition OFF.
- Disconnect: LTM C4174a or Liftgate Ajar Switch C4185.
- Do the courtesy lamps illuminate?

Yes
If equipped with a power liftgate, GO to B4.

If equipped with a manual liftgate, INSTALL a new liftgate latch. REFER to Handles, Locks, Latches and Entry Systems Removal and Replacement. TEST the system for normal operation.

No
GO to B2.

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


- Disconnect: SJB C2280c.
- Measure the resistance between the SJB C2280c-16, circuit CPL58 (GY/OG), harness side and ground.




- Is the resistance greater than 10,000 ohms?

Yes
GO to B3.

No
REPAIR circuit CPL58 (GY/OG) for a short to ground. CLEAR the DTCs. REPEAT the self-test.

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B3 CHECK FOR CORRECT SJB OPERATION


- Disconnect all the SJB connectors.
- Check for:
- corrosion
- damaged pins
- pushed-out pins

- Connect all the SJB 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. REFER to Multifunction Electronic Modules 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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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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