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 Descriptors

DTC B0525 00: Front Right Turn Indicator Circuit Malfunction
DTC B0530 00: Front Left Turn Indicator Circuit Malfunction

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
Left Front Turn Signal Lamp Control | B0530 00 | B0530 00 | 1 | --
Right Front Turn Signal Lamp Control | B0525 00 | B0525 00 | 1 | --
Left Rear Stop/Turn Lamp Control | 1 | 1 | 1 | --
Right Rear Stop/Turn Lamp Control | 1 | 1 | 1 | --
Left Front Repeater Lamp Control | B3868 00 | B3868 00 | 2 | --
Right Front Repeater Lamp Control | B3869 00 | B3869 00 | 2 | --
Left Rear Stop/Turn Lamp Ground | -- | 1 | -- | --
Right Rear Stop/Turn Lamp Ground | -- | 1 | -- | --
Left Front Repeater Lamp Ground | -- | 2 | -- | --
Right Front Repeater Lamp Ground | -- | 2 | -- | --
Turn Signal Lamp - LF Ground | -- | 1 | 1 | --
Turn Signal Lamp - RF Ground | -- | 1 | 1 | --
1. Turn Signal Lamps and/or Indicators Malfunction 2. Repeater Lamps Malfunction

### Circuit/System Description

The turn signal switch is integrated into the steering column module. When the turn signal switch is activated, the steering column module interprets the position of the switch and sends a serial data message to the underhood electrical center (UEC) and the rear electrical center (REC) requesting either the right or left turn signals be activated. The UEC and REC respond by applying a pulsating voltage to the appropriate turn signal control circuits to illuminate the front and rear turn signal lamps. The steering column module also sends a serial data message to the instrument panel cluster (IPC) requesting the appropriate turn signal indicator be illuminated.

### Conditions for Running the DTC

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

• | Right turn signals ON.

### Conditions for Setting the DTC

#### B0525 00

The DTC will set when the UEC detects a short to ground or an open/high resistance in the right front turn signal control circuit.

#### B0530 00

The DTC will set when the UEC detects a short to ground or an open/high resistance in the left front turn signal control circuit.

### Actions Taken When the DTC Sets

#### B0525 00

When DTC B0525 00 is present, the right front turn signal lamp will not operate.

#### B0530 00

When DTC B0530 00 is present, the left front turn signal lamp will not operate.

### Conditions for Clearing the DTC

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

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

### Reference Information

#### Schematic Reference

Exterior Lights Schematics

#### Connector End View Reference

Component Connector End Views

#### Description and Operation

Exterior 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 appropriate headlamp assembly.
2. Ignition OFF, exterior lamps OFF, test for less than 5.0 ohms between the ground circuit terminal 1 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 5 and ground.
4. Command the Front Turn Signal 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 UEC.

⇒ | 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 UEC.

5. If all circuits test normal, replace the inoperative front turn signal.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Front Turn Signal Lamp Bulb Replacement

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