B3618

DTC B3618

Diagnostic Instructions

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



DTC Descriptor
DTC B3618 02
- Exterior Trunk Release Switch Circuit Short to Ground




Diagnostic Fault Information






Circuit/System Description

The exterior rear compartment lid release switch receives a signal from the remote control door lock receiver (RCDLR). When the exterior rear compartment lid release switch is activated the signal circuit is pulled to ground. The RCDLR interprets this and sends a GMLAN serial data message to the rear integration module (RIM) requesting the rear compartment lid be released. The rear integration module (RIM) grounds the trunk release relay control circuit which energizes the TRK DR REL relay. The trunk release relay is supplied with battery voltage at all times. With the relay coil energized, the relay switch contacts close allowing battery voltage to flow to the rear compartment lid release actuator causing the rear compartment lid to release. The rear compartment lid release actuator is permanently grounded at G402.


Conditions for Running the DTC

Battery voltage must be between 9-16 volts.


Conditions for Setting the DTC

DTC B3618 02 will set when the RCDLR detects a short to ground in the exterior trunk release switch signal circuit.


Action Taken When the DTC Sets

* The RCDLR stores the DTC to memory.
* The exterior trunk release switch will not operate.
* All other functions to open the rear compartment lid will operate normally.



Conditions for Clearing the DTC

* The condition responsible for setting the DTC no longer exists.
* A history DTC will clear once 40 consecutive malfunction free ignition cycles have occurred.



Reference Information
Schematic Reference

* Remote Function Schematics ([1][2]Electrical Diagrams)
* Release Systems Schematics (Release Systems Schematics)

Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

Luggage Compartment Description and Operation (Description and Operation)
Electrical Information Reference

* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)

Scan Tool Reference

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


Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the exterior rear compartment lid release switch.
2. Ignition OFF, exterior lamps OFF, test for less than 5.0 ohms between the ground circuit terminal C and ground.

• If greater than the specified range, test the ground circuit for an open/high resistance.

3. Ignition ON, verify the scan tool trunk release switch parameter is INACTIVE.

• If not the specified value, test the signal circuit terminal A for a short to ground. If the circuit tests normal, replace the RCDLR.

4. Install a 3A fused jumper wire between the signal circuit terminal A and ground. Verify the scan tool trunk release switch parameter displays ACTIVE.

• If not the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the RCDLR.

5. If all circuits test normal, test or replace the exterior rear compartment lid release switch.



Repair Instructions

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

* Rear Compartment Lid Switch Replacement (Exterior) (Service and Repair)
* Control Module References (Programming and Relearning) for RCDLR replacement, setup, and programming