Pinpoint Test C: The Luggage Compartment/Cargo Lamp Is Inoperative

Interior Lighting

Pinpoint Test C: The Luggage Compartment/Cargo Lamp Is Inoperative

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

Normal Operation

The Body Control Module (BCM) sends a voltage signal to the luggage compartment lid/liftgate ajar switch (integrated into the latch) to monitor the ajar switch status. The switch is normally closed when the luggage compartment lid/liftgate is closed, and open when the luggage compartment lid/liftgate is open. The ajar switch also controls the ground side of the luggage compartment lamp. The luggage compartment ajar switch completes the path to ground for the luggage compartment/cargo lamp when the luggage compartment lid/liftgate is open.

- DTC B1178:92 (Boot/Trunk Ajar Switch: Performance Or Incorrect Operation)- an on-demand DTC that sets when the BCM (Body Control Module) detects an open from the luggage compartment lid/liftgate ajar input circuit.

This pinpoint test is intended to diagnose the following:

- Wiring, terminals or connectors

- Luggage compartment lid/liftgate latch

- Luggage compartment/cargo lamp

PINPOINT TEST C : THE LUGGAGE COMPARTMENT/CARGO LAMP IS INOPERATIVE

NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.

C1 CHECK THE COURTESY LAMP OPERATION

- Open the LH front door and observe the interior lamps.

Do the courtesy lamps illuminate?

Yes
GO to C2.

No
GO to Pinpoint Test A Pinpoint Test A: The Courtesy Lamps Do Not Illuminate With A Door Open.

C2 CHECK THE LUGGAGE COMPARTMENT LID/LIFTGATE AJAR PID

- Ignition ON.

- Enter the following diagnostic mode on the scan tool: BCM (Body Control Module) DataLogger.

- Monitor the BCM (Body Control Module) luggage compartment lid/liftgate ajar switch PID while opening and closing the luggage compartment lid/liftgate.

Does the PID agree with the luggage compartment lid/liftgate positions?

Yes
GO to C3.

No
If the PID always indicates closed, GO to C6.

If the PID always indicates open, GO to C8.

C3 CHECK FOR VOLTAGE TO THE LUGGAGE COMPARTMENT/CARGO LAMP

- Ignition OFF.

- Open the luggage compartment lid/liftgate.

- Disconnect: Luggage Compartment/Cargo Lamp C489.

- Measure the voltage between the luggage compartment/cargo lamp C489-1, circuit CLN01 (GN/VT), harness side and the luggage compartment lamp C489-2, circuit CLN13 (WH/BU).





Is the voltage greater than 10 volts?

Yes
INSTALL a new luggage compartment lamp. TEST the system for normal operation.

No
GO to C4.

C4 CHECK THE LUGGAGE COMPARTMENT/CARGO LAMP VOLTAGE SUPPLY CIRCUIT FOR AN OPEN

- Measure the voltage between the luggage compartment/cargo lamp C489-1, circuit CLN01 (GN/VT), harness side and ground.





Is the voltage greater than 10 volts?

Yes
GO to C5.

No
REPAIR circuit CLN01 (GN/VT) for an open. TEST the system for normal operation.

C5 CHECK THE LUGGAGE COMPARTMENT/CARGO LAMP GROUND CIRCUIT FOR AN OPEN

- Connect: Luggage Compartment/Cargo Lamp C489.

- Disconnect: Luggage Compartment Lid/Liftgate Latch C4223.

- Measure the voltage between the luggage compartment lid/liftgate latch C4223-4, circuit CLN13 (WH/BU), harness side and ground.





Is the voltage greater than 10 volts?

Yes
INSTALL a new luggage compartment lid/liftgate latch. TEST the system for normal operation.

No
REPAIR circuit CLN13 (WH/BU) for an open. TEST the system for normal operation.

C6 RECHECK THE PID WITH THE LUGGAGE COMPARTMENT/LIFTGATE LATCH DISCONNECTED

- Disconnect: Luggage Compartment Lid/Liftgate Latch C4223.

- Enter the following diagnostic mode on the scan tool: BCM (Body Control Module) DataLogger.

- Monitor the BCM (Body Control Module) luggage compartment lid/liftgate ajar switch PID.

Does the PID indicate the luggage compartment lid/liftgate is open?

Yes
INSTALL a new luggage compartment lid/liftgate latch. TEST the system for normal operation.

No
GO to C7.

C7 CHECK THE LUGGAGE COMPARTMENT/LIFTGATE AJAR INPUT CIRCUIT FOR A SHORT TO GROUND

- Ignition OFF.

- Disconnect: BCM (Body Control Module) C2280G.

- Measure the resistance between the luggage compartment lid/liftgate latch C4223-3, circuit CPL44 (YE/OG), harness side and ground.





Is the resistance greater than 10,000 ohms?

Yes
GO to C11.

No
REPAIR circuit CPL44 (YE/OG) for a short to ground. TEST the system for normal operation.

C8 BYPASS THE LUGGAGE COMPARTMENT/LIFTGATE LATCH

- Ignition OFF.

- Disconnect: Luggage Compartment Lid/Liftgate Latch C4223.

- Ignition ON.

- Connect a fused jumper wire between the luggage compartment lid/liftgate latch C4223-3, circuit CPL44 (YE/OG), harness side and the luggage compartment lid/liftgate latch C4223-2, circuit GD143 (BK/VT), harness side.





- Enter the following diagnostic mode on the scan tool: BCM (Body Control Module) DataLogger.

- Monitor the BCM (Body Control Module) luggage compartment lid/liftgate ajar switch PID.

Does the PID indicate the luggage compartment lid/liftgate is closed?

Yes
REMOVE the jumper wire. INSTALL a new luggage compartment lid latch. TEST the system for normal operation.

No
REMOVE the jumper wire. GO to C9.

C9 BYPASS THE LUGGAGE COMPARTMENT/LIFTGATE LATCH GROUND CIRCUIT

- Connect a fused jumper wire between the luggage compartment lid/liftgate latch C4223-3, circuit CPL44 (YE/OG), harness side and ground.





- Enter the following diagnostic mode on the scan tool: BCM (Body Control Module) DataLogger.

- Monitor the BCM (Body Control Module) luggage compartment lid/liftgate ajar switch PID.

Does the PID indicate the luggage compartment lid/liftgate is closed?

Yes
REMOVE the jumper wire. REPAIR circuit GD143 (BK/VT) for an open. TEST the system for normal operation.

No
REMOVE the jumper wire. GO to C10.

C10 CHECK THE LUGGAGE COMPARTMENT/LIFTGATE AJAR INPUT CIRCUIT FOR AN OPEN

- Ignition OFF.

- Disconnect: BCM (Body Control Module) C2280G.

- Measure the resistance between the BCM (Body Control Module) C2280G-7, circuit CPL44 (YE/OG), harness side and the luggage compartment lid/liftgate latch C4223-3, circuit CPL44 (YE/OG), harness side.





Is the resistance less than 5 ohms?

Yes
GO to C11.

No
REPAIR circuit CPL44 (YE/OG) for an open. TEST the system for normal operation.

C11 CHECK FOR CORRECT BCM (Body Control Module) OPERATION

- Disconnect all BCM (Body Control Module) the connectors.

- Check for:
- corrosion

- damaged pins

- pushed-out pins


- Connect all the BCM (Body Control 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 BCM (Body Control 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.