If, in the case of the above-mentioned vehicle models with automatic running lights, the headlights are not set on "AUTO" in the headlight control switch, a possible cause of failure may be a defective ambient light sensor.
This sensor is integrated in the rain sensor module.
When troubleshooting, first check the manual switch functions, the wiring and then the power supply for defects.
If no further faults are found, the ambient light sensor should be checked and replaced if necessary.
Please follow the repair instructions specified by the vehicle manufacturer for the carrying out of such work.
Important safety notice
The following technical information and tips for practical use have been set up by HELLA in order to offer professional support to automotive workshops in their daily work. The information available here on this website is only to be used by appropriately trained specialist staff.
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