BMW E34 Check Control and instrument cluster warnings
Why does the E34 Check Control show false warnings?
The cause is usually a sensor, bulb, connector or wiring. Cheap LED bulbs trigger the warning, and the brake pad wear warning can come on if the wear sensor connector is not seated properly. The washer fluid warning can be caused by a dirty or wrongly oriented sensor or an empty rear washer reservoir.
What do the Check Control messages mean and how are they read?
The fault message appears when the CHECK button is pressed, and it is not supposed to appear by itself. A + sign indicates several faults. 'Tür offen' means door open, 'Kofferaum offen' boot open and 'Kein Bremslight' brake light not working, usually a fuse or bulb. The language can be changed to English by turning the key to position 1 and pressing the CC button.
Why does Check Control report a door open fault or a constant warning?
Check the door light switches and the boot wiring harness at the hinge. If the warning comes on constantly while driving, the trip computer's speed limiter (Limit) may be on; it is switched off via the bottom row of the trip computer.
Why does Check Control show a trailer light fault when there is no trailer?
Oxidised contacts in the tow bar socket make the car think a trailer is connected. Alternatively, grounding the blue-yellow wire at the rear connector in the left boot hatch removed the warning in a car without a tow bar.