TRACS/ABS: 70: ABS module or something else?

[Orchid70]

A friend bought a V70 from 2000 - the front axel is from MK2, the rest is MK1.
Last week the ABS and Tracs control lights came on.
He had someone to read the fault codes and front left ABS sensor was to blame.
They changed the ABS sensor and could not turn off the fault codes.
He came to me and VIDA gives following codes:
ECM510D Speed signal faulty signal
ABS0011 ABS sensor left front faulty signal
ABS0012 ABS sensor left front faulty signal

When I had turned the codes off, I took it for a drive and it took good 100 meters before the lights came back on - so I asked them to check the ABS rings.

He did change it and came back to me.
I still couldnt turn the codes off.

So I resistance measured both front ABS sensors and they had the same resistance: 64,2 kohm.

Then I took it for a ride again and the results for both ABS sensorns are in the picture - the left sensor doesnt give right speed signal.

The question is - shall I send the module for repair?
Or can it be the gap between sensor and tone ring??
He says there is no other issues (wheel bearing or front axel).

Ive changed a ABS module on one MK1 before - but on that car all the fault lamps went crazy, it was the DIM (instrument cluster) that gave the symptoms that time.

[SteveSarre]

Hi Orchid

You say "the front axel is from MK2, the rest is MK1"
I don't understand.


Has this car worked before, or is this the first time you have tested it since fitting Mk2 parts? I dont know which parts you have taken from a Mk2. Can you tell us?

Which ABS sensors are being used on the front wheel bearing hubs? There are at least 2 different types.

Can you go to https://www.volvopartswebstore.com/ and choose Select vehicle -
year, V70 etc and find the Volvo part numbers of the ABS sensors? And compare the sensors that you have with the normal sensors that Volvo shows?
Also check the part numbers for the reluctor rings. They may be different between MK1 and Mk2.

The ABS system always tests itself after you start the engine and drive away - when the car gets to a certain speed. Maybe that's why it threw codes after 100m.

Steve

[Orchid70]

Unfortunatelly I was not even consulted when this happened so our friend bought the sensor himself....
And now when you say it - I went to see what he bought and he has bought the wrong one - the MK2 sensor....
As it looks like right now at least - I cant get hold of him right now.
Ill let you know when I find out.

The tone ring is the same for both.

[volvo again]

Had a similar problem on mine, the reluctor rings were the problem. Caused as they get older rust forms underneath them and they can crack & split.
Quite easy to replace, although it will mean removing drive shaft, they are just a press fit but will need heating to fit on.

[Orchid70]

The tone/regulator ring have been changed. They had to knock the old one out (when they are cracked they fall out).
A correct sensor has been ordered and should arrive on Monday.

[Orchid70]

Letting you know that after changing to the right sensor - the fault remained.
So the sensor never was the problem.
He'll propably leave the car here so I can find the fault.
He have also tried to change the ABS box to an other from scrab yeard.

[Luxobarge]

Next thing I'd be doing before changing the module is to take it apart and re-solder the PCB in it - a very common fault on these, and easy enough to do if you can do soldering OK - lots of threads on here about it, also in the technical articles section.

[Orchid70]

Originally Posted by Luxobarge

Next thing I'd be doing before changing the module is to take it apart and re-solder the PCB in it - a very common fault on these, and easy enough to do if you can do soldering OK - lots of threads on here about it, also in the technical articles section.

He has changed the module to an other one from the scrap. The same. No change.
Thats what I thought, that it would bee the module and thats why he bought an other one.