GM Service Manual Online
For 1990-2009 cars only

Diagnostic Instructions

    • 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.

DTC Descriptors

DTC B2495 01: Liftgate Latch Control Circuit Short to Battery

DTC B2495 02: Liftgate Latch Control Circuit Short to Ground

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Liftgate Relay Switch B+

2

2

--

--

Liftgate Release Switch Signal

1, 2

1

1

--

Liftgate Relay Low Control

--

2

B3265 00

--

Liftgate Relay High Control

B2495 02

2

B2495 01

--

Liftgate Latch Control

2

2

2

--

Liftgate Latch Ground

--

2

2

--

Liftgate Switch Ground

--

1

1

--

1. Liftgate Release Switch Malfunction

2. Liftgate Release Malfunction

Circuit/System Description

Pressing the liftgate switch closes a contact providing a ground for the rear closure handle switch open signal circuit. The body control module (BCM) will detect the voltage drop and command voltage to be supplied to the liftgate latch relay supply voltage circuit thus energizing the liftgate relay which provides voltage to the liftgate latch releasing the liftgate.

Conditions for Running the DTC

Battery voltage must be between 9-16 volts.

Conditions for Setting the DTC

B2495 01

When the BCM detects a short to voltage on the liftgate relay control circuit.

B2495 02

When the BCM detects a short to ground on the liftgate relay control circuit.

Action Taken When the DTC Sets

The liftgate will be inoperative.

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

Release Systems Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Rear Hatch/Gate Description and Operation

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

Command the liftgate release by pressing the liftgate release switch. The liftgate latch assembly should release the liftgate.

Circuit/System Testing

  1. Ignition OFF, disconnect the X1 harness connector at the I/P fuse block.
  2. Connect a test lamp between the control circuit terminal 6 and ground.
  3. Command the liftgate latch assembly ON and OFF by pressing and releasing the liftgate release switch, the test lamp should turn ON and OFF when changing between the commanded states.
  4. If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the BCM.
    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 BCM.
  5. If all circuits test normal, replace the I/P fuse block.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Instrument Panel Wiring Harness Junction Block Replacement
    •  Control Module References for BCM replacement, setup, and programming