ABS and rear window heater [Archive] - Bimmerfest - BMW Forums

: ABS and rear window heater

09-06-2008, 11:04 AM
Hi, first my apologie for all, my english is bad but I hope you will understand me.

I have two (for me) big problems. First is ABS, control lamp for abs is "on" I am cheak ABS sensors on connectors under rear seat, and on front weels....everything is OK, on my osciloscope. Fuse is ok. Where problem could be? If a sensor is OK (working good) and in same time is a dirt, can this be a problem? Diagnostic on my car doesn't work. I forget this is a BMW 535i e34.

SEcond problem is: Does anybody know where is relay for heater on rear window? My switch is OK but I don't have electric power on a cable for this heater.


bimmer dot info
09-08-2008, 07:46 AM
If you can get the car to a mechanic with the proper code reader they can read the ABS fault code.

I do not have my manual with me and I am not 100% sure where the relay is. Have you checked both fuse boxes? Under the hood and under the rear seat?

09-08-2008, 01:29 PM
Well first if the light remains on like you say the ABS system fault has occurred and the ABS system is electronically disabled. You still have normal braking. The problem might be in the "ABS Pulse Sensors". I would suggest you take it to a BMW specialist.

09-09-2008, 04:55 AM
In BMW sevice, they thry tryed to connect ABS with diagnostic comp. and didn't work that connection because I have problems with diagnostic on my car. And nobody doesn;t like to fix problem manualy. Everybody trying with diagnostic. So I'am take this problem in "my hands". First I was check sensors on my 4 wheels, when I remove ABS unit (modul or ECU) from my car on my bord comuter blinking "check control" so my opinion is ECU of ABS is OK.

For second problem I was checked both fuse boxes and relay's under rear seat. But I couldn't know witch relay is for rear window heater.