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 B2570 00: Trunk Lamp Circuit Malfunction

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
Cargo Lamp Control | B2570 00 | B2570 00 | 1 | --
Cargo Lamp Ground | -- | 1 | -- | --
1. Courtesy Lamps Malfunction

### Circuit/System Description

The cargo lamps are controlled by the rear electrical center (REC). When the rear hatch is opened, the REC receives a door ajar signal from the liftgate latch assembly indicating the hatch is open. The REC responds by applying voltage to the cargo lamp control circuit illuminating the cargo lamps. The cargo lamps are permanently grounded at grounds G401 and G403.

### Conditions for Running the DTC

• | Battery voltage must be between 9-16 volts.

• | Rear hatch OPEN.

### Conditions for Setting the DTC

The DTC will set when the REC detects a short to ground or an open/high resistance in the cargo lamp control circuit when the rear hatch is open.

### Actions Taken When the DTC Sets

The REC will disable the cargo lamp control circuit.

### Conditions for Clearing the DTC

• | The condition responsible for setting the DTC no longer exists.

• | A history DTC will clear once 100 malfunction-free ignition cycles have occurred.

### Reference Information

#### Schematic Reference

Interior Lights Schematics

#### Connector End View Reference

Component Connector End Views

#### Description and Operation

Interior Lighting Systems 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 Testing

1. Ignition OFF, disconnect the harness connector at the inoperative cargo lamp.
2. Ignition OFF, exterior lamps OFF, test for less than 5.0 ohms between the ground circuit terminal 2 and ground.

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

3. Connect a test lamp between the control circuit terminal 1 and ground.
4. Command the Trunk Lamp Test ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.

⇒ | If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the REC.

⇒ | 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 REC.

5. If all circuits test normal, replace the inoperative cargo lamp.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Cargo Lamp Replacement

• | Control Module References for REC replacement, setup, and programming