DTC B3435 or B3440. Cadillac CTS 2008

For 1990-2009 cars only

Makes 🢒 Cadillac 🢒 2008 🢒 CTS 🢒 Body Systems 🢒 Lighting 🢒 DTC B3435 or B3440

DTC B3435 or B3440 Base

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 B3435 00: AHLD Left Servo Driver Circuit

DTC B3435 02: AHLD Left Servo Driver Circuit Short to Ground

DTC B3435 39: AHLD Left Servo Driver Circuit Internal Electronic Failure

DTC B3435 54: AHLD Left Servo Driver Circuit Over Temperature

DTC B3440 00: AHLD Right Servo Driver Circuit

DTC B3440 02: AHLD Right Servo Driver Circuit Short to Ground

DTC B3440 39: AHLD Right Servo Driver Circuit Internal Electronic Failure

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 Motor Control Circuit 1 - Left	B3435 02	B3435 00	B3435 00	B3435 39, B3435 54
Headlamp Leveling Motor Control Circuit 2 - Left	B3435 02	B3435 00	B3435 00	B3435 39, B3435 54
Headlamp Leveling Motor Control Circuit 3 - Left	B3435 02	B3435 00	B3435 00	B3435 39, B3435 54
Headlamp Leveling Motor Control Circuit 4 - Left	B3435 02	B3435 00	B3435 00	B3435 39, B3435 54
Headlamp Leveling Motor Control Circuit 1 - Right	B3440 02	B3440 00	B3440 00	B3440 39, B3440 54
Headlamp Leveling Motor Control Circuit 2 - Right	B3440 02	B3440 00	B3440 00	B3440 39, B3440 54
Headlamp Leveling Motor Control Circuit 3 - Right	B3440 02	B3440 00	B3440 00	B3440 39, B3440 54
Headlamp Leveling Motor Control Circuit 4 - Right	B3440 02	B3440 00	B3440 00	B3440 39, B3440 54

Circuit/System Description

Each headlamp assembly contains a headlamp leveling motor that is controlled by the headlamp control module. The front and rear suspension position 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 00

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

B3435 02

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

B3435 39

The headlamp control module detects an internal electronic failure.

B3435 54

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

B3440 00

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

B3440 02

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

B3440 39

The headlamp control module detects an internal electronic failure.

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 and the ignition is cycled.

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

Reference Information

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

Ignition OFF, disconnect the harness connector at the inoperative headlamp.
Remove the AFS 15A fuse.
Ignition OFF, scan tool OFF, test for 10 ohms -25K ohms between each control circuit terminal listed below and ground.

•	Headlamp leveling motor control terminal 1

•	Headlamp leveling motor control terminal 2

•	Headlamp leveling motor control terminal 3

•	Headlamp leveling motor control terminal 4

⇒	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.

Install the AFS 15A fuse.
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 1

•	Headlamp leveling motor control terminal 2

•	Headlamp leveling motor control terminal 3

•	Headlamp leveling motor control terminal 4

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

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

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

•	Headlamp Assembly or Headlamp Bulb and/or Cornering, Sidemarker, Park, Turn Signal Bulb Replacement

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