Headlamp Leveling Malfunction (V-Series)
Headlamp Leveling Malfunction (V-Series)
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.
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 electronic suspension control (ESC) module with suspension position information. Each sensor receives a 5 V reference, signal, and low reference circuits from the ESC. 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 ESC sends the suspension position sensor values to the headlamp control module via serial data. 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.
Reference Information
Schematic Reference
* Headlights/Daytime Running Lights (DRL) Schematics Headlights/Daytime Running Lights (DRL) Schematics
* Electronic Suspension Control Schematics Electrical Diagrams
Connector End View Reference
Component Connector End Views Connector Views
Description and Operation
Exterior Lighting Systems Description and Operation Exterior Lighting Systems
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 Control Module References for scan tool information
Circuit/System Verification
Ignition ON, with a scan tool, command the DHL Motor Control Up and Down while observing both headlamps. Both headlamps should operate to the Up and Down positions when commanded.
Circuit/System Testing
1. Ignition OFF, disconnect the harness connector at the appropriate headlamp.
2. Remove the AFS 15 A fuse.
3. Ignition OFF, scan tool OFF, test for 10 ohm-25K ohm 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.
4. Install the AFS 15 A 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 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.
6. If all circuits test normal, replace the 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 (TT6) Headlamp Assembly or Headlamp Bulb and/or Cornering, Sidemarker, Park, Turn Signal Bulb Replacement (TT6)Headlamp Assembly or Headlamp Bulb and/or Cornering, Sidemarker, Park, Turn Signal Bulb Replacement (TT7) Headlamp Assembly or Headlamp Bulb and/or Cornering, Sidemarker, Park, Turn Signal Bulb Replacement (TT7)Headlamp Assembly or Headlamp Bulb and/or Cornering, Sidemarker, Park, Turn Signal Bulb Replacement (TT8) Headlamp Assembly or Headlamp Bulb and/or Cornering, Sidemarker, Park, Turn Signal Bulb Replacement (TT8)Headlamp Assembly or Headlamp Bulb and/or Cornering, Sidemarker, Park, Turn Signal Bulb Replacement (Without TT6/TT7/TT8/T84/T85) Headlamp Assembly or Headlamp Bulb and/or Cornering, Sidemarker, Park, Turn Signal Bulb Replacement (Without TT6/TT7/TT8/T84/T8
* Control Module References Control Module References for headlamp control module replacement, setup, and programming