• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
• | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
• | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
---|---|---|---|---|
Switch Signal Circuit | 2 | 2 | -- | -- |
Switch Ground Circuit | -- | 2 | -- | -- |
Latch Motor Voltage Control Circuit | 1 | 1 | 1 | -- |
Latch Motor Voltage Ground Circuit | -- | 1 | -- | -- |
Trunk Release Relay Control Circuit | 1 | 1 | 1 | -- |
1. Trunk release is inoperative from both the switch and keyless entry transmitter. 2. Trunk release is inoperative only from switch. |
The rear compartment lid can be released by operating the rear compartment lid release switch or by pressing the rear compartment lid release button on the remote keyless entry transmitter. The gear selector may be in any position, but the vehicle speed must equal 0 for the liftgate to release.
When the ignition is ON, the body control module (BCM) supplies battery positive voltage to the rear compartment lid release switch through the trunk release switch supply voltage circuit. When the rear compartment lid release switch is operated, the trunk release supply voltage circuit is grounded through the switch ground circuit and the voltage is pulled low within the BCM. In response, the BCM applies ground to the trunk release relay control circuit, which energizes the coil side of the trunk relay. The switch side of the trunk relay then closes, supplying battery positive voltage through the relay and the latch motor voltage control circuit to the rear compartment lid latch. The rear compartment lid latch, which is grounded to G302, then releases the rear compartment lid so that it may be manually raised to an open position.
Vehicle Access Connector End Views
⇒ | If greater than 1.0 ohm, test the ground circuit for an open/high resistance. |
⇒ | If not Inactive, test the signal circuit for a short to ground. If the circuit tests normal, replace the BCM. |
⇒ | If not Active, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM. |
⇒ | If the rear compartment lid latch is still active, test the voltage control circuit for a short to voltage. |
⇒ | If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit tests normal and the B+ circuit fuse is open, test the voltage control circuit for a short to ground. If the circuit tests normal, test or replace the Trunk Relay. |
⇒ | If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. |
⇒ | If greater than 1.0 ohm, test the ground circuit for an open/high resistance. |
⇒ | If the lid latch does not activate, test or replace the rear compartment lid latch. |
⇒ | If the test lamp remains ON all the time, test the control circuit for a short to ground. If the circuit tests normal, replace the BCM. |
⇒ | If the test lamp remains OFF all the time, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM. |
⇒ | If less than infinite resistance, replace the rear compartment lid release switch. |
⇒ | If greater than 2 ohms, replace the rear compartment lid release switch. |
⇒ | If less than infinite resistance, replace the rear compartment lid release switch. |
⇒ | If the resistance is not within the specified range, replace the Trunk Relay. |
• | 30 and 86 |
• | 30 and 87 |
• | 30 and 85 |
• | 85 and 87 |
⇒ | If less than infinite resistance, replace the relay. |
⇒ | If greater than 2 ohms, replace the relay. |
⇒ | If the resistance is not within the specified range, replace the lid latch. |
Important: Apply power and ground to the rear compartment lid latch for no more than 2 seconds at a time or the actuator could be damaged.
⇒ | If the function does not perform as specified, replace the lid latch. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for BCM replacement, setup, and programming |