Volkswagen Golf IV - Illumination of the malfunction indicator lamp | HELLA

If a customer complains about the above problem, this could be caused by defective stop light bulbs. When reading out the error code, a faulty stop light switch is indicated. After this is replaced, the problem persists and cannot be cleared. Therefore, the two stop light bulbs should be checked beforehand. If the two lamps are defective (not the LED bar in the boot lid), this is the probable cause of the problem. After replacing the lamps, the entry can usually be cleared from the fault memory. The two defective lamps cause a false signal to be sent from the stop light switch to the engine control unit. This then interprets the signal as a defective stop light switch.