paalw

My (!) light comes on every time 5-10 seconds after i start driving, and the ABS warning is also lit.

Reason for this according to PO is that he ordered a wrong rear axle when replacing it, and the ABS sensor gets too far away from the wheel or something like that.

The car is an 86.5(ROW) and he supposedly ordered the pre-86.5 and put it on.

Does this make sense? Would a part from an earlier model fit?
Are there ABS sensors on both rear sides? (because I don't know what side of the car the change was made)

Just asking here before i start to look under the car and turn in to a (?) myself. I want to fix this so any help is much appreciated.

Tampa 928s

There are different tooth counts for some years that could be the problem.

Tampa 928s

Sorry; there are one for all wheels, look in the WSM it will show you how to diagnose the sensors. If you have access to an oscilloscope you can know for sure if you need info on the ABS pm me I have the info you need.

soupcan

My guess is the PO "fixed" the problem with a used non-abs bearing carrier rather than replacing the bearing itself, and the sensor is tied up under the car.

Jfrahm

You can also look at the voltages from the four wheel sensors at the ABS brain. If one of them is zero, then you have a wiring problem to that wheel or as you suspect, no ABS reluctor ring on that axle.

Search this forum enough and you might find the post where I did this and noted which pins to measure voltage on. I did this with the car slowly driving around my block and a DMM on the passenger's seat.

-Joel.

Mrmerlin

from your post removing the ABS sensors and counting the ABS splines on each Half shaft ( throught the ABS sensor hole) should let you know what going on as there are different ABS CV joints

ZEUS+

From 86 on the tooth count is 45, early abs had a 90 tooth count.

paalw

i checked the voltage on the ABS computer input from each sensor, they are all 0.95V at idle. but it seems that the left rear stays at 0.95V when driving + - 10mph, while the other ones go up to 1,15-1.30V.

Any ideas what is most likely the problem? bad sensor or sensor out of position because of wrong rear axle?

If tooth count is different i can't see how a pre 86.5 axle can fit an 86.5?

paalw

These teeth you talk about, they are the "ABS teeht" that the sensor responds to? Or are we talking about teeth on the end of the axle to go into the wheel?

i have an 86,5, and according to 928intl pages i should have 928 332 033 41 early axles 90 tooth, after checking my VIN(GS841882). Correct?

ROG100

From what I know about ABS systems and their parts the 32v 86 cars supplied only to Sweden, Switzerland and Australia were what we call 86.5 cars - used the S4 suspension & brakes.
Is this car a 32v car or 16v?? If it is a 16v car and it maybe as it is in Norway it would also use the later ABS setup.
PET for ROW cars in this catorgory does not differentiate between 86 and 86.5 as the US/Canada PET does.
VIN GS841882 makes this an 86 car and as such should use rear ABS sensor 928 606 402 01 if it is 32v or 16v.

I would feel better if Erkka confirmed my findings.

We sell the ABS sensor 928 606 402 01 for $183

123quattro

Based on the voltage at the left rear not changing with speed, I'd say there is a very good chance of this.

Vilhuer

AFAIK all ROW '86 MY cars have later style "S4" suspension. No matter if its 16V or 32V, S, UK only S2 or S with 32V engine which was extra cost option in Germany and Austria. There were no '86.0 vs '86.5 change in ROW markets at all. All '86 ROW are like '86.5 US versions other than maybe some later running changes which were done in different times than '86.5 change. This includes all those few 100 M298 and M299 32V S models made, even ones which were made before November 1985 cut off point when US '86.0 vs '86.5 change was done.

Above is however different thing than which teeth count ABS they have. But I think "S4" suspension always means later ABS with smaller teeth count in hub at front and in driveshaft at rear.

'84-85 MY used different driveshaft depending on if M593 ABS option was included or not. All '86 ROW should have later shafts with smaller number of teeth as stock and thus also ABS as default. Very likely there is no separate option code for it.

If early ABS shaft or even earlier teethless shaft is used in ROW '86 or US '86.5 then ABS will obviously cause problems. Probably same thing will happen if early sensor is used when rest of the system is later variant. Or at least early vs late, large vs small number of teeth systems use different sensors.

So problem can either be wrong driveshaft with too many or no teeth at all or wrong type sensor in one rear wheel hub.

paalw

It is a 16V yes. With the S4 brakes and suspension. Old or new ABS - I don't know.

It will be exciting to see how things look when i jack it up. I will have a closer look when it is back from TB/WP job.

Still no answer on the axle teeth, are the teeth we talk about here only for ABS purpose?

Vilhuer

Yes, only for ABS.

ROG100

Hi Erkka,
So basically I had it right - thanks for the clarification.
Roger