B3420

DTC B3410 or B3420

Diagnostic Instructions

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

DTC Descriptor
DTC B3410 01
- Automatic Headlamp Leveling Control Module Front Axle Sensor Signal Circuit Short to Battery

DTC B3410 06
- Automatic Headlamp Leveling Control Module Front Axle Sensor Signal Circuit Low Voltage/Open

DTC B3420 01
- Automatic Headlamp Leveling Control Module Rear Axle Sensor Signal Circuit Short to Battery

DTC B3420 06
- Automatic Headlamp Leveling Control Module Rear Axle Sensor Signal Circuit Low Voltage/Open

Diagnostic Fault Information





Circuit/System Description

The front and rear suspension position sensors provide the headlamp control module with front and rear suspension position information. Each sensor receives a 5 V reference, signal, and low reference circuits from the headlamp control module. The sensors are connected to the control arms at 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 sensors to change. The headlamp control module compares the information from the front and rear suspension position sensors and adjusts the headlamp leveling as needed.

Conditions for Running the DTC

* Battery voltage must be between 9-16 V.
* The ignition is in the ON or RUN position.

Conditions for Setting the DTC

B3410 01 or B3420 01

The DTC will set when the headlamp control module detects high voltage on the sensor signal line.

B3410 06 or B3420 06

The DTC will set when the headlamp control module detects no signal or low voltage on the sensor signal line.

Conditions for Clearing the DTC

The condition responsible for setting the DTC no longer exists.

Reference Information
Schematic Reference

Headlights/Daytime Running Lights (DRL) Schematics (Headlights/Daytime Running Lights (DRL) 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 (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing For Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)

Scan Tool Reference

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

Circuit/System Verification

Verify that DTC B3415 is not present.

If DTC is present, refer to DTC B3415 (B3415).

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the appropriate headlamp leveling sensor.
2. Disconnect the negative terminal of the C1 Battery.
3. Test for less than 5 ohm between the low reference circuit terminal 1 and ground.

• If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the K26 Headlamp Control Module.

4. Reconnect the negative terminal to the C1 Battery.
5. Ignition ON, test for 4.8-5.2 V between the 5 V reference circuit terminal 3 and ground.

• If less than the specified range, test the 5 V reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K26 Headlamp Control Module.
• If greater than the specified range, test the 5 V reference circuit for a short to voltage. If the circuit tests normal, replace the K26 Headlamp Control Module.

6. Verify the appropriate scan tool Leveling Position Sensor parameter is 0 mm.

• If greater than the specified range, test the signal circuit terminal 2 for a short to voltage. If the circuit tests normal, replace the K26 Headlamp Control Module.

7. Install a 3 A fused jumper wire between the signal circuit terminal 2 and the 5 V reference circuit terminal 3. Verify the appropriate scan tool Leveling Position Sensor parameter is greater than 0 mm.

• If less than the specified range, test the signal circuit for short to ground or an open/high resistance. If the circuit tests normal, replace the K26 Headlamp Control Module.

8. If all circuits test normal, replace the appropriate headlamp leveling sensor.

Repair Instructions

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

* Link X 71886
* Link X 71887
* Control Module References (Programming and Relearning) for headlamp control module replacement, setup, and programming