I have a 1997 BMW 528i which is giving false read-outs… Randomly, brake light, headlight out light, etc come on, then go off next time I start the car. What’s up? Can I fix this myself? Is it a computer or battery problem?
I will take a look around but 1997 is out of the “bulb match” days ( what I mean is ,with BMW’s “inoperative bulb indicator” system in use durning the late 70’s and all the way up to the early 90’s you would see this type of thing when the bulbs had slightly different amperage draw,as in what happens when they come from different manufactures, I belive this is not the case for 1997). As always with BMW, it goes TSB check and then you can just bet on a module re-program. In this case it would be either the “general module” (better known as the “GM”) or perhaps an issue with the instrument cluster as it is a bit of a junction in this system.
Sure a chronicly low battery will cause odd issues. I am going with a module reprogram for now.
After checking that there are no issues with the battery I suggest a “re-code” of the "lamp check module’. After BMW got into the 90’s with the 5 series things really started getting complex in the electrical system, not bad by any means ,just complex. The last BMW that I think was still on “planet Earth” in regards to an electrical system that could be diagnoised with just general knowledge about electronics was the e-36 3 series (up until 1999). Your car is a great car, just a bit complex.
Thanks! I was able to replace the inside door handle last week myself, so I was overly optimistic that I may be able to do more. Time to see an expert. Should I go to a dealer?
Dealer or BMW specific independant. They must have some moderately sophisicated programing equipment. The tech is going to have to work through a sucession of modules and see which ones need re-coding. I bet this car has 8 modules that could be considered “computers”. Eight was just a rough guess, it could be more, not all are involved with the lamp check issue but I am certain 3 are.