E36 320 ABS fault

[gingerpaul]

Hi all.

I've for the last few months the ABS light hasn't gone out on the 320 when you turn the car on. I've checked it and the ABS is indeed off when the light is on. It started as an intermittent problem and has now become a permanent feature of the dash. It doesn't really bother me because I know that I no longer have ABS so drive accordingly, but now I'm due for an MOT I need to get it sorted.

I've done a search here and elsewhere and found these links:

Linky1
Linky2

I've been round and checked the ABS sensors and they all appear to function correctly (approx 1090 Ohm resistance and generate a small ac voltage when the wheel is spun by hand). The fact that the light stays on permanently is further evidence of this I think as if it was a fault on a sensor you would expect it to go out and then come on again once moving I would have thought?

I've checked the grey ABS relay and that is functioning correctly too. This unfortunately leads me to believe that something expensive / tricky must have either failed or become disconnected.

The last person to work on the brakes was a back street mechanic who changed the rear brake lines for me when I didn't have time to do it myself. In researching this problem I notice the BMW DIS tool should have been plugged in to put new fluid in, but I doubt he would have had the equipment. Is this a prossible cause of the fault?

Is my best bet from here to go to a specialist and plug into their computer to see what fault codes are showing up?

Thanks in advance!

Edited to fix links.

Edited by gingerpaul on Tuesday 11th September 16:10

[neil_bolton]

Just replace the ABS sensor.

Very common fault on many types of marques.

ETA: They often go when disturbed during brakes services etc.

Edited by neil_bolton on Tuesday 11th September 16:38

[gingerpaul]

The problem is they're about £45 each and from what I've been reading can be a real pain to replace. I don't really want to spend £180 on something that may or may not fix the problem. I'd gladly do it if I knew which one was at fault though.

Since posting this I've been quoted £25 to plug into the DIS machine at a BMW specialist. Apparantly this has the ability to say which of the sensors, if any, are at fault and whether there is a fault with the control unit itself. I think this is probably going to be the way to go, unless anyone has any other suggestions for me.