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 109, Power Liftgate for schematic and connector information. Diagrams By Number
Refer to Wiring Diagram Set 117, Remote Keyless Entry and Alarm for schematic and connector information. Diagrams By Number
Normal Operation
The Smart Junction Box (SJB) sends a voltage signal to the liftgate ajar switch (manual liftgate) or the Liftgate/Trunk Module (LTM) (power liftgate).
For vehicles with a manual liftgate, the voltage signal is then routed to ground through the liftgate ajar switch. The liftgate ajar switch is closed when the liftgate is closed. When the liftgate is opened, the signal to ground is interrupted, indicating an open liftgate to the SJB.
For vehicles with a power liftgate, the LTM provides ground to the SJB through the SJB liftgate ajar input circuit when the liftgate is closed. When the liftgate is opened, the LTM removes ground, indicating an open liftgate to the SJB.
- 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 SJB liftgate ajar input circuit.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Liftgate ajar switch
- 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 COURTESY LAMP OPERATION FROM ANY DOOR
- Ignition OFF.
- Open any door and observe the courtesy lamps.
- Do the courtesy lamps illuminate?
Yes
GO to B2.
No
GO to Pinpoint Test A. Pinpoint Test A: The Courtesy Lamps Do Not Illuminate With A Door Open
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B2 CHECK THE LTM OR THE LIFTGATE LATCH
- Disconnect: Liftgate Latch C479 (Manual Liftgate) or LTM C4174b (Power Liftgate).
- Do the courtesy lamps illuminate?
Yes
If equipped with a manual liftgate, INSTALL a new manual liftgate latch. REFER to Doors, Hood and Trunk &/or Locks. TEST the system for normal operation.
If equipped with a power liftgate, GO to B5.
No
GO to B3.
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B3 CHECK THE LIFTGATE AJAR INPUT CIRCUIT FOR A SHORT TO GROUND
- Disconnect: SJB C2280c.
- Measure the resistance between the SJB C2280c-16, circuit CPL60 (BN/YE), harness side and ground.
- Is the resistance greater than 10,000 ohms?
Yes
GO to B4.
No
REPAIR circuit CPL60 (BN/YE) for a short to ground. CLEAR the DTCs. REPEAT the self-test.
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B4 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 Body Control Systems. 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. CLEAR the DTCs. REPEAT the self-test.
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B5 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 Doors, Hood and Trunk. 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. CLEAR the DTCs. REPEAT the self-test.
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