My turn signals stopped working, the seatbelt indicator remains lit even when the seatbelts are engaged, and the dash lights are staying on even when the car is off and the key removed. The convertible top is also not working. My car starts fine, though I have noticed the occasional battery indicator light coming on.
It sounds like you may have a problem with the communication bus or one of the control modules on it. In a situation like yours where multiple seemingly unrelated problems occur, BMW suggests monitoring the bus for proper communication voltage, then removing the defective modules from the bus. Test the modules for proper power and ground and replace as needed. A trained mechanic with the proper diagnostic equipment can inspect your electrical components to see what is necessary for repair.
Have a car question? Get free advice from our top-rated mechanics.
Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Save up to 30%