For 1990-2009 cars

### 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
--- | --- | --- | --- | ---
Tonneau Release Relay B+ | 1 | 1 | -- | --
Trunk Release Switch Signal | B2730 00 | 2 | 2 | --
Tonneau Latch Control | 1 | 1 | 1 | --
Tonneau Release Relay Control | B3265 00 | B3265 00 | B3265 00 | --
Tonneau Latch Ground | -- | 1 | 1 | --
Rear Closure Release Switch Ground | -- | 2 | 2 | --
1. Tonneau Latch Malfunction 2. Rear Closure Release Switch Malfunction

### 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 tonneau release switch signal circuit. When the rear closure release switch is pressed, the voltage within the signal circuit is pulled low and in response, the BCM applies ground to the tonneau release relay control circuit, which energizes the coil side of the tonneau relay. The switch side of the tonneau relay then closes, supplying battery positive voltage through the relay and the latch motor voltage control circuit to the tonneau latch. The tonneau latch, then releases the tonneau cover 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 closure release switch is closed for greater than 10 minutes.

### Action Taken When the DTC Sets

The rear closure 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

#### Connector End View Reference

Component Connector End Views

#### Description and Operation

Tonneau Cover 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 closure release switch button. The parameter should change between Active and Inactive.

### Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the rear closure release switch.
2. Test for less than 1 ohm between the ground circuit terminal B 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 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 BCM.

4. 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.

⇒ | 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.

5. If all circuits test normal, test or replace the rear closure release switch.

### Component Testing

1. Ignition OFF, disconnect the harness connector at the rear closure release switch.
2. Test for infinite resistance between the signal terminal A and the ground terminal B with the switch in the open position.

⇒ | If not the specified value, replace the rear closure release switch

3. Test for less than 2 ohms of between the signal terminal A and the ground terminal B with the switch in the closed position.

⇒ | If greater than the specified range, replace the rear closure release switch.

4. Test for infinite resistance between each terminal and the lid release switch housing/case.

⇒ | If not the specified value, replace the rear closure release switch.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for BCM replacement, setup and programming