Failure of the headlight range adjustment
If the headlights are moved to the lowest adjusting position, there is usually a fault in the headlight range adjustment system. Moving down the headlights signals the fault, since there is no warning light in the cockpit. In such a case proceed as follows:
1. Read out the fault code with an appropriate diagnostic tester. For this purpose, select the “Lichtschaltzentrum” (light switching centre) menu item after selecting the vehicle (see Fig. 1).
2. In this case, a faulty power supply on the front vehicle level sensor will be detected (see Fig. 2).
3. Now check the actual values of the sensor under the “Messwerte und Parameter” (measured values and parameters) menu item. The value for the front sensor (load sensor) will be 0.2volts, which is much too low. Also, the value will not change by simulating a change in the vehicle level.
4. Raise the vehicle and check the connector and wiring of the sensor for damage and corrosion. If no problems can be found, an internal fault in the sensor must be assumed.
5. Replace the vehicle level sensor.
6. After replacing the front sensor, its value will be 2.2volts, which is in the nominal range (see Fig. 3).
7. Tune the vehicle's suspension and adjust the headlights according to the manufacturer's instructions.
Fig. 1
Fig. 2
Fig. 3
Important safety note
Technical information and practical tips have been compiled by HELLA in order to provide professional support to vehicle workshops in their day-to-day work. The information provided on this website is intended for use by suitably qualified personnel only.
Reprinting, distribution, reproduction, exploitation in any form or disclosure of the contents of this document, even in part, is prohibited without our express, written approval and indication of the source. The schematic illustrations, pictures and descriptions serve only for the purposes of explanation and representation of the instructions and cannot be used as a basis for installation or assembly work. All rights reserved.
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