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 B3435 02: AHLD Left Servo Driver Circuit Short to Ground
DTC B3435 05: AHLD Left Servo Driver Circuit Short to Battery or Open
DTC B3435 54: AHLD Left Servo Driver Circuit Over Temperature
DTC B3440 02: AHLD Right Servo Driver Circuit Short to Ground
DTC B3440 39: AHLD Right Servo Driver Circuit Short to Battery or Open
DTC B3440 54: AHLD Right Servo Driver Circuit Over Temperature

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
Headlamp Leveling Sensor 5 Volt Reference - Front | B3415 02 | 1 | B3415 01 | --
Headlamp Leveling Sensor 5 Volt Reference - Rear | 1 | 1 | 1 | --
Headlamp Leveling Sensor Signal - Front | B3410 02 | B3410 05 | B3410 05 | B3410 08
Headlamp Leveling Sensor Signal - Rear | B3420 02 | B3420 05 | B3420 05 | B3420 08
Headlamp Leveling Motor Control Circuit 1 - Left | B3435 02 | B3435 05 | B3435 05 | B3435 54
Headlamp Leveling Motor Control Circuit 2 - Left | B3435 02 | B3435 05 | B3435 05 | B3435 54
Headlamp Leveling Motor Control Circuit 3 - Left | B3435 02 | B3435 05 | B3435 05 | B3435 54
Headlamp Leveling Motor Control Circuit 4 - Left | B3435 02 | B3435 05 | B3435 05 | B3435 54
Headlamp Leveling Motor Control Circuit 1 - Right | B3440 02 | B3440 05 | B3440 05 | B3435 54
Headlamp Leveling Motor Control Circuit 2 - Right | B3440 02 | B3440 05 | B3440 05 | B3435 54
Headlamp Leveling Motor Control Circuit 3 - Right | B3440 02 | B3440 05 | B3440 05 | B3435 54
Headlamp Leveling Motor Control Circuit 4 - Right | B3440 02 | B3440 05 | B3440 05 | B3440 39, B3440 54
Headlamp Leveling Sensor Low Reference - Front | -- | 1 | 1 | --
Headlamp Leveling Sensor Low Reference - Rear | -- | 1 | 1 | --
1. Headlamp Leveling Malfunction

### Circuit/System Description

Each headlamp assembly contains a headlamp leveling motor that is controlled by the headlamp control module. The front and rear headlamp leveling sensors provide the headlamp control module with suspension position information. Each sensor receives a 5-volt reference, signal, and low reference circuits from the headlamp control module. The sensors are connected to the control arms of the front and rear suspension. As the vehicle travels, the suspension compresses and rebounds moving the suspension position sensor arms. This causes the signal output of the sensor to change. The headlamp control module compares the information from both suspension position sensors and adjusts the headlamp leveling as needed. The headlamp control module is wired to each headlamp leveling motor with 4 directional motor control circuits.

### Conditions for Running the DTC

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

• | Ignition in the ON or RUN position.

• | Headlamps ON.

### Conditions for Setting the DTC

#### B3435 02

The headlamp control module detects a short to ground on any of the left motor control circuits.

#### B3435 05

The headlamp control module detects a short to voltage or an open/high resistance on any of the left motor control circuits.

#### B3435 54

The headlamp control module detects an overheating condition on any of the left motor control circuits.

#### B3440 02

The headlamp control module detects a short to ground on any of the right motor control circuits.

#### B3440 05

The headlamp control module detects a short to voltage or an open/high resistance on any of the right motor control circuits.

#### B3440 54

The headlamp control module detects an overheating condition on any of the right motor control circuits.

### Actions Taken When the DTC Sets

• | When DTC B3435 or DTC B3440 sets, the headlamp control module will attempt to return the lamps to a nominal position and disable all requests to all headlamp actuators.

• | The driver information center (DIC) will display AFL Lamps Need Service.

### Conditions for Clearing the DTC

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

• | A history DTC will clear once 50 consecutive malfunction-free cycles have occurred.

### Reference Information

#### Schematic Reference

Headlights 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 inoperative headlamp.
2. Remove the COMM ENABLE 10A fuse.
3. Ignition OFF, scan tool OFF, test for 20K -22K ohms between each control circuit terminal listed below and ground.

• | Headlamp leveling motor control terminal 3

• | Headlamp leveling motor control terminal 4

• | Headlamp leveling motor control terminal 5

• | Headlamp leveling motor control terminal 10

⇒ | If greater than the specified range, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the headlamp control module.

⇒ | If less than the specified range, test the control circuit for a short to ground. If the circuit tests normal, replace the headlamp control module.

4. Install the COMM ENABLE 10A fuse.
5. Ignition ON, scan tool OFF, headlamps ON, verify that a test lamp does not illuminate between each control circuit terminal listed below and ground.

• | Headlamp leveling motor control terminal 3

• | Headlamp leveling motor control terminal 4

• | Headlamp leveling motor control terminal 5

• | Headlamp leveling motor control terminal 10

⇒ | If the test lamp illuminates, test the control circuit for a short to voltage. If the circuit tests normal, replace the headlamp control module.

6. If all circuits test normal, replace the appropriate headlamp assembly.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Headlamp Replacement

• | Control Module References for headlamp control module replacement, setup, and programming