Operation CHARM: Car repair manuals for everyone.
Home >> Cadillac >> 2008 >> CTS AWD V6-3.6L >> Repair and Diagnosis >> A L L Diagnostic Trouble Codes ( DTC ) >> Testing and Inspection >> B Code Charts >> B3440

B3440



DTC B3435 or B3440

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category.



DTC Descriptors
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/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.
* The ignition is in the ON or RUN position.
* The headlamps are ON.



Conditions for Setting the DTC

B3435 00

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

B3435 39

The DTC will set when the headlamp control module detects an internal electronic failure.

B3435 54

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

B3440 00

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

B3440 39

The DTC will set when the headlamp control module detects an internal electronic failure.

B3440 54

The DTC will set when 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

Headlight Leveling Schematics (Headlight Leveling Schematics)
Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

Exterior Lighting Systems Description and Operation (Exterior Lighting Systems Description and Operation)
Electrical Information Reference

* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)

Scan Tool Reference

Control Module References (Programming and Relearning) for scan tool information


Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the appropriate headlamp leveling motor.
2. Ignition OFF, test for less than 10.0 ohms between the motor control circuit terminal 1 and ground.

• 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.

3. Ignition OFF, test for less than 10.0 ohms between the motor control circuit terminal 2 and ground.

• 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.

4. Ignition OFF, test for less than 10.0 ohms between the motor control circuit terminal 3 and ground.

• 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.

5. Ignition OFF, test for less than 10.0 ohms between the motor control circuit terminal 4 and ground.

• 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.

6. Connect a test lamp between control circuit terminal 1 and control circuit terminal 3.
7. Command the DHL motor control to the UP and DOWN positions with a scan tool. The test lamp should turn ON when commanding the UP and DOWN states.

• If the test lamp remains OFF during either of the commands, test for a short to ground on either control circuit. If the circuits test normal, replace the headlamp control module.

8. Connect a test lamp between control circuit terminal 2 and control circuit terminal 4.
9. Command the DHL motor control to the UP and DOWN positions with a scan tool. The test lamp should turn ON when commanding the UP and DOWN states.

• If the test lamp remains OFF during either of the commands, test for a short to ground on either control circuit. If the circuits test normal, replace the headlamp control module.

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



Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.

* Headlamp Assembly or Headlamp Bulb and/or Cornering, Sidemarker, Park, Turn Signal Bulb Replacement (Minus TT6/TT7/TT8/T84/T85) (Service and Repair)Headlamp Assembly or Headlamp Bulb and/or Cornering, Sidemarker, Park, Turn Signal Bulb Replacement (T84/T85) (Service and Repair)Headlamp Assembly or Headlamp Bulb and/or Cornering, Sidemarker, Park, Turn Signal Bulb Replacement (TT6) (Service and Repair)Headlamp Assembly or Headlamp Bulb and/or Cornering, Sidemarker, Park, Turn Signal Bulb Replacement (TT8) (Service and Repair)Headlamp Assembly or Headlamp Bulb and/or Cornering, Sidemarker, Park, Turn Signal Bulb Replacement (TT7) (Service and Repair)
* Control Module References (Programming and Relearning) for headlamp control module replacement, setup, and programming


pro multis · About Operation CHARM