GM Service Manual Online
For 1990-2009 cars only

DTC B2730 Sedan

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 Descriptor

DTC B2730 00: Interior Trunk/Liftglass/Hatch Release Switch Circuit

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Trunk Relay B+

1

1

--

--

Trunk Release Switch Signal

B2730 00

2

2

--

Rear Compartment Lid Latch Control

1

1

1

--

Trunk Release Relay Control

B3265 00

B3265 00

B3265 00

--

Rear Compartment Lid Latch Ground

--

1

1

--

Rear Compartment Lid Release Switch Ground

--

2

2

--

1. Trunk release is inoperative from both the switch and keyless entry transmitter

2. Trunk release is inoperative only from switch

Circuit/System Description

When the ignition is ON, the body control module (BCM) supplies a signal to the rear compartment lid release switch through the trunk release switch signal circuit. When the rear compartment lid release switch is pressed, the voltage within the signal circuit is pulled low and 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, then releases the rear compartment lid so that it may be manually raised to an open position.

Conditions for Running the DTC

The system voltage is 9-16 volts.

Conditions for Setting the DTC

    • The BCM detects a short to ground in the trunk release switch signal circuit for greater than 10 minutes.
    • The rear compartment lid release switch is closed for greater than 10 minutes.

Action Taken When the DTC Sets

The rear compartment lid release switch 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 become 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

Luggage Compartment 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

Ignition ON, observe the scan tool Trunk Switch parameter while pressing the rear compartment lid release switch button. The parameter should change between Active and Inactive.

Circuit/System Testing

  1. Ignition OFF, disconnect the harness connector at the rear compartment lid release switch.
  2. Test for less than 1 ohm between the ground circuit terminal B and ground.
  3. If greater than the specified range, test the ground circuit for an open/high resistance.
  4. Ignition ON, verify the scan tool Trunk Switch parameter is Inactive.
  5. If not the specified value, test the signal circuit terminal A for a short to ground. If the circuit tests normal, replace the BCM.
  6. Install a 3A fused jumper wire between the signal circuit terminal A and the ground circuit terminal B. Verify the scan tool Trunk Switch parameter is Active.
  7. 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 BCM.
  8. If all circuits test normal, test or replace the rear compartment lid release switch.

Component Testing

  1. Ignition OFF, disconnect the harness connector at the rear compartment lid release switch.
  2. Test for infinite resistance between the signal terminal A and the ground terminal B with the switch in the open position.
  3. If not the specified value, replace the rear compartment lid release switch
  4. Test for less than 2 ohms of between the signal terminal A and the ground terminal B with the switch in the closed position.
  5. If greater than the specified range, replace the rear compartment lid release switch.
  6. Test for infinite resistance between each terminal and the lid release switch housing/case.
  7. If not the specified value, replace the rear compartment lid release switch.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Rear Compartment Lid Release Switch Replacement
    •  Control Module References for BCM replacement, setup and programming

DTC B2730 Wagon

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 Descriptor

DTC B2730 00: Interior Trunk/Liftglass/Hatch Release Switch Circuit

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Rear End Release Relay Switch B+

2

2

--

--

Liftgate Release Switch Signal

B2730 00

1

1

--

Rear End Release Relay Coil Control

--

2

2

--

Rear End Release Relay Coil Control

B3265 00

2

2

--

Liftgate Latch Control

--

2

2

--

Liftgate Latch Ground

--

2

2

--

Liftgate Release Switch Ground

--

1

1

--

1. Liftgate Release Switch Malfunction

2. Liftgate Release Malfunction

Circuit/System Description

When the ignition is ON, the body control module (BCM) supplies a signal to the liftgate release switch through the liftgate release switch signal circuit. When the liftgate release switch is pressed, the voltage within the signal circuit is pulled low and in response, the BCM applies ground to one end of the relay control circuit and power to the other end, which energizes the coil side of the relay. The switch side of the rear end relay then closes, supplying battery positive voltage through the relay and the latch motor voltage control circuit to the liftgate latch. The liftgate latch, then releases the liftgate so that it may be manually raised to an open position.

Conditions for Running the DTC

The system voltage is 9-16 volts.

Conditions for Setting the DTC

    • The BCM detects a short to ground in the liftgate release switch signal circuit for greater than 10 minutes.
    • The liftgate release switch is closed for greater than 10 minutes.

Action Taken When the DTC Sets

The liftgate release switch 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 become 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

Ignition ON, observe the scan tool Trunk Switch parameter while pressing the liftgate release switch. The parameter should change between Active and Inactive.

Circuit/System Testing

  1. Ignition OFF, disconnect the harness connector at the liftgate release switch.
  2. Test for less than 1 ohm between the ground circuit terminal B and ground.
  3. If greater than the specified range, test the ground circuit for an open/high resistance.
  4. Ignition ON, verify the scan tool Trunk Switch parameter is Inactive.
  5. If not the specified value, test the signal circuit terminal A for a short to ground. If the circuit tests normal, replace the BCM.
  6. Install a 3A fused jumper wire between the signal circuit terminal A and the ground circuit terminal B. Verify the scan tool Trunk Switch parameter is Active.
  7. 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 BCM.
  8. If all circuits test normal, test or replace the liftgate release switch.

Component Testing

  1. Ignition OFF, disconnect the harness connector at the liftgate release switch.
  2. Test for infinite resistance between the signal terminal A and the ground terminal B with the switch in the open position.
  3. If not the specified value, replace the liftgate release switch
  4. Test for less than 2 ohms between the signal terminal A and the ground terminal B with the switch in the closed position.
  5. If greater than the specified range, replace the liftgate release switch.
  6. Test for infinite resistance between each terminal and the lid release switch housing/case.
  7. If not the specified value, replace the liftgate release switch.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for BCM replacement, setup, and programming