B324A

DTC B324A

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Diagnostic Procedure Instructions)provides an overview of each diagnostic category.

DTC Descriptor
DTC B324A 02
- Rear Cargo Door Unlock Motor Circuit Short to Ground

Diagnostic Fault Information





Circuit/System Description

When the body control module receives a liftgate release command, it will provide voltage to one side of the relay and ground to the other side of the relay. This will energize the relay causing the switch side of the relay to close and will then provide B+ voltage to the liftgate latch.

Conditions for Running the DTC

* The system voltage is 9-16 volts.
* When the relay is actively commanded by the BCM

Conditions for Setting the DTC

The BCM detects a short to ground in the RR CLOSURE relay control circuit.

Actions Taken When DTC Sets

The liftgate latch will malfunction.

Conditions for Clearing the DTC

* The DTC will be current for as long as the fault is present.
* When the fault is no longer present, the DTC will be a history DTC.
* A history DTC will clear after 50 ignition cycles.

Reference Information
Schematic Reference

Liftgate Schematics (Liftgate Schematics)
Connector End View Reference

Component Connector End Views (Connector End Views By Name)
Description and Operation

Rear Hatch/Gate Description and Operation (Rear Hatch/Gate)
Electrical Information Reference

* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)

Scan Tool Reference

Control Module References (Programming and Relearning)for scan tool information

Circuit/System Verification

Doors UNLOCKED, command the M31 liftgate latch assembly to release by pressing the S58A rear compartment lid release switch - exterior. The M31 liftgate latch assembly should release the liftgate.

Circuit/System Testing

1. Ignition OFF, disconnect the RR CLOSURE relay.
2. Connect a test lamp between the control circuit terminal 85 and ground.
3. Ignition ON, command the Endgate Unlatch with a scan tool. The test lamp should turn ON when commanding the UNLATCH state.

• If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K9 BCM.

• If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the K9 BCM.

4. If all circuits test normal, test or replace the RR CLOSURE relay.

Component Testing

1. Ignition OFF, disconnect the RR CLOSURE relay.
2. Test for 60-200 ohm between terminals 85 and 86.

• If not within the specified range, replace the RR CLOSURE relay.

3. Test for infinite resistance between the following terminals:

* 30 and 86
* 30 and 87
* 30 and 85
* 85 and 87

• If not the specified value, replace the RR CLOSURE relay.

4. Install a 3A fused jumper wire between relay terminal 85 and 12V. Install a jumper wire between relay terminal 86 and ground. Test for less than 2 ohm between terminals 30 and 87.

• If greater than the specified range, replace the RR CLOSURE relay.

Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.

* Relay Replacement (Attached to Wire Harness) (Relay Replacement (Attached to Wire Harness))Relay Replacement (Within an Electrical Center) (Relay Replacement (Within an Electrical Center))
* Control Module References (Programming and Relearning)for BCM replacement, setup and programming