GM Service Manual Online
For 1990-2009 cars only

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 Descriptor

DTC B3410 00: AHLD Front Axle Sensor Signal Circuit

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Headlamp Leveling Switch Bit 1 Signal-Front

B3410 00, 1

B3410 00, 1

B3410 00, 1

--

Headlamp Leveling Switch Bit 1 Signal-Rear

B3420 00, 1

B3420 00, 1

B3420 00, 1

--

Headlamp Leveling Actuator-Left Control

B3420 00, 1

B3420 00, 1

B3420 00, 1

--

Headlamp Leveling Actuator-Right Control

B3410 00, 1

B3410 00, 1

B3410 00, 1

--

Headlamp Leveling Sensor-Front Control

B3410 00, 1

B3410 00, 1

B3410 00, 1

--

Headlamp Leveling Sensor-Rear Control

B3420 00, 1

B3420 00, 1

B3420 00, 1

--

Headlamp Leveling Actuator-Left Ground

--

1

--

--

Headlamp Leveling Actuator-Right Ground

--

1

--

--

Headlamp Leveling Sensor-Front Ground

--

1

--

--

Headlamp Leveling Sensor-Rear Ground

--

1

--

--

1. Headlamp Leveling Malfunction

Circuit/System Description

The front suspension position sensor provides the headlamp leveling modules with front suspension position information. The sensor is permanently grounded and has voltage supplied with the ignition in the ON or CRANK position. The sensor arm is connected to the control arm of the front suspension. As the vehicle travels, the suspension compresses and rebounds moving the suspension position sensor arm. This causes the signal output of the sensor to change. The headlamp leveling modules compare this information with the rear suspension position sensor information and adjusts the headlamp leveling as needed.

Conditions for Running the DTC

    • Battery voltage must be between 9-16 volts.
    • The ignition is in the ON or CRANK position.
    • The headlamps are ON.

Conditions for Setting the DTC

DTC B3410 00 will set when the headlamp leveling module detects a fault, an internal counter in each of the headlamp leveling modules is increased by 1. When the counter reaches 5 the DTC is set as current.

Actions Taken When the DTC Sets

When DTC B3410 00 is present, the headlamp leveling modules use an internal offset of the headlamp leveling sensor rear in order to keep the leveling system active.

Conditions for Clearing the DTC

    • The condition responsible for setting the DTC no longer exists.
    • A history DTC will clear once 40 consecutive malfunction-free cycles have occurred.

Diagnostic Aids

Important: When one of the suspension position sensor voltage reference or sensor signal circuits are shorted to ground, it may not be possible to determine which suspension position sensor voltage reference or sensor signal circuits, front or rear, has failed. If this condition occurs, all suspension position sensor voltage reference and sensor signal circuits will have to be tested for a short to ground.

Reference Information

Schematic Reference

Headlight Leveling 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 front headlamp leveling sensor.
  2. Ignition OFF, test for less than 5.0 ohms between the ground circuit terminal 1 and ground.
  3. If greater than the specified range, test the ground circuit for an open/high resistance.
  4. Ignition ON, test for B+ between the voltage reference circuit terminal 5 and ground.
  5. If less than the specified range, test the voltage reference circuit for a short to ground or an open/high resistance.
  6. Disconnect the X 111 harness connector at the left headlamp assembly.
  7. Ignition ON, verify that a test lamp does not illuminate between the front headlamp leveling switch signal circuit terminal 4 and ground.
  8. If the test lamp illuminates, test the signal circuit for a short to voltage. If the circuit tests normal, test or replace the right headlamp assembly.
  9. Disconnect the X 112 harness connector at the right headlamp assembly.
  10. Ignition OFF, verify that a test lamp does not illuminate between the front headlamp leveling switch signal circuit terminal 4 and B+.
  11. If the test lamp illuminates, test the signal circuit terminal 4 for a short to ground.
  12. Ignition OFF, verify that a test lamp does not illuminate between the front headlamp leveling switch signal circuit terminal E and B+.
  13. If the test lamp illuminates, test the signal circuit terminal E for a short to ground.
  14. Disconnect the harness connector at the rear headlamp leveling sensor.
  15. Ignition OFF, verify that a test lamp does not illuminate between the rear headlamp leveling switch signal circuit terminal B and B+.
  16. If the test lamp illuminates, test the signal circuit terminal B for a short to ground.
  17. Connect the X 112 harness connector a the right headlamp assembly.
  18. Verify with a DMM that continuity is present between the front headlamp leveling switch signal circuit terminal 4 and terminal E at the X 111 harness connector at the left headlamp assembly.
  19. If continuity is not present, test the signal circuit for an open/high resistance. If the circuit tests normal, test or replace the right headlamp assembly.
  20. If all circuits test normal, test or replace the front headlamp leveling sensor.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Headlamp Replacement
    •  Headlamp Aiming
    •  Relay Replacement
    •  Underhood Electrical Center or Junction Block Replacement
    •  Headlamp Leveling Front Suspension Height Sensor Replacement
    •  Headlamp Leveling Rear Suspension Height Sensor Replacement
    •  Control Module References for headlamp leveling module replacement, setup, and programming