Initial Inspection and Diagnostic Overview

Automatic vertical headlight aim control On Board Diagnostic (OBD)

Function
In order to reduce glare for oncoming traffic, vehicles with gas-discharge lamps must be equipped with an automatic vertical headlight aim control.

Automatic vertical headlight aim control keeps the tilt angle of the low beams constant, even when vehicle tilt is different due to a load shift.

The automatic vertical headlight aim control system that is built into Passat vehicles consists of the following components:

- Headlight range control module -J431-
- Both level control system sensors, left rear -G76- and left front -G78-
- Left/right headlight beam adjusting motors -V48- / -V49-

The level control system sensors are located at the front and rear axles on the left side of the vehicle.

See Repair Manual, Suspension, Wheels, Steering, Repair Group 40: level control system sensors in vehicles with dynamic vertical headlight aim control regulation.

See Repair Manual, Suspension, Wheels, Steering, Repair Group 42; level control system sensors in vehicles with dynamic vertical headlight aim control regulation.

Manual adjustment is no longer possible. The basic setting procedure must therefore be performed in order to adjust the headlights.

If an electric malfunction occurs in the automatic headlight aim control system during driving, headlights remain in this position.

When the vehicle is started again, the adjustment motors adjust the headlights to the lowest position.

This makes the driver aware of the malfunction.

For troubleshooting, initiate On Board Diagnostic (OBD) and read out stored data using the VAG 1551 Scan Tool (ST).