View Full Version : Newby to BMW, need ECM help on 93 525i

09-08-2008, 05:39 PM
Hello bimmer lovers, I just bought my 525i a week ago. I also bought the performance chip. I took out the rear seats, the panel above the gas pedal and no ECM. Were is it? Can someone help. Also need to replace lower contraol arms. I have some experience with cars. How hard are these to get off without taking off everything to get to it? Well I found it, being dumb I forgot to disconnect the battery. A spark happened. It was a piece that has to positive cables running into two nuts. Now the car will not start, but it turns over. Can someone give me some ideas. I do not here the fuel pump charging, but I think that it is not the problem maybe a relay or fuse. The thing that sparked is not getting power, it sets right next to the relays next to the ECM.

bimmer dot info
09-09-2008, 07:04 AM
Control arms are not that bad. You need some wrenches, jack, jack stands, and something to set the wheels on (wheel ramps). Rent or buy a ball joint puller also.

Where was the spark? Did you pull the ECU without disconnecting the battery? Was the piece that has two positive cables with 2 nuts the fusible link box?

09-09-2008, 07:45 AM
The spark happened I think the ECU was disconneted at the time. The piece that sparked doesn't have any power going through it. But everything works on the car just no primimg of the fuel pump. I am getting a relay today to try that first. Anything else I can do. Is there a fuse going to the relay box that protects it.

09-09-2008, 07:55 AM
also no chime when the key is left in

09-09-2008, 08:27 AM
Check the 80A fuse link on the passenger side of the battery below the rear seat.

09-10-2008, 08:46 AM
Thanks, That was it. It was a link in the positive cable that is integrated within.