Porsche Enthusiasts Club Forum

Guys, Done a lot of work on new brake pipes and bled the brakes but now ABS ligth won't go otu. I haven't tested all the sensors and ECU as I haven't realy done anythign to them and they worked fine before. I did disconnect the ECU for qwelding purposes (big plug drivers feet)

Does the ABS soemhow know about brake fluid ?? does it need bleeding ? i did replace the pipe from the ABS unit to the rear of the car.

I dont; think ABS actually works but the ligth used to go out ???

I can't move the car yet but have had the engine running.

Any thoughst ? By the way i think it definately is an MOT failure regardless of whether the barkes actually work. The wifes BMW failed with it and i got a second opinion. Appaarentyl its meant to do what it says in teh mainual thatmy MOT had a look at..if its says it goes out its meant to go out...doesn't ..FAIL.

Thoughts please . BTW 1989 2.7 Lux.

I did have a simular problem on another vehicle. The ABS light was on after disconnecting the ECU, it returned to normal after being driven a few miles.

Not sure why the light is coming on but if you want to get it through an MOT you could remove the bulb

HI
Not sure i can help - I did alot of work on the brakes on my 2.7 aswell a few months back - including removal of the ABS pump unit. I did find alot of crud on the ABS ECU connector and in the end replaced my ECU whch seemed to sort my fault out (again a dash light that wouldn't extinguish). I had no difficulties bleeding the brake system
Thanks
Ian

Thanks guys sounds like it might be OK if i clean it up a bit and drive it. BUT..thought i would check the sensors whilst I have teh car laid up. but i can't read the page in the manual.

I am on page 45-04 in the chassis section which is a wiring diagram for the ABS. I can't decipher the pin numbers on the connector. I can read about 50% of them. Has anyone got a better copy or picture ? Thanks Ian.

Chaps. Right found a copy I can read. worked out how the plug is numbered and all my sensors are a whisker over 1 K ohms so they are fine. (Not that we thought they caused the light to be on but reassuring all teh same). Whilst I am putting my probes into the plaug..anything alse you can test ? From the wiring diagram I could check 10, 20 & 34 are earthed. can you check the ABS solenoids on 2, 35 & 18 back to 32...it looks like it from the diagram. Any other thoughts ? I also noticed that the ABS relay in the fuse box looks a bit more complicated than the wiring diagram ?

The only thing I can suggest is changing the ABS relay in the fusebox for a known good one.
I made the mistake in my resto of putting the wrong relay back here , and getting the ABS light on.
Installing the correct relay fixed this.
There are also a couple of relays ON the ABS unit itself in the o/s wing - but I gather this unit rarely fails...?
Ian