ABS fault diagnosis

[greenspider]

I recently bought a V70, 2.4 auto, 2000 facelift model. I bought it knowing there were issues, with all of the dash warning lights on and the abs cutting in occasionally at very low speeds when there is obviously no requirement for it. This morning I took it to a friends garage to have the fault codes read. There were many, as follows:

ENGINE CODES
ECM-510D vehicle speed signal
ECM-911A throttle unit communication, faulty signal
ECM-6400 camshaft reset valve
ECM-A02B communication, control module for abs
ECM-250A long term fuel trim

ABS CODES
ABS-0092 yaw rate sensor, faulty signal
ABS-0095 communication between control modules. communication problems with Active on demand coupling
ABS-0010 left front wheel sensor, signal missing
ABS-0011 left front wheel sensor, faulty signal
ABS-0021 right front wheel sensor, faulty signal

So, not knowing if any were historical concerns that hadn't been reset, we deleted all codes, then read them again to see if any popped up instantly. Nothing came back up immediately, and the plan is now to drive the car as normal for a day and read them again tomorrow. About a mile into the drive home all of the abs lights came back on. No engine light yet.

I was just wondering if any of you that are experienced in repairing these cars might have come across such a list of abs codes and have an idea of what the cause might actually be. I mean for example, I can see that front wheel sensors are both listed, but with the communication code, I wonder if it could just be the abs ecu playing up and failing to communicate with the various sensors or something. I will of course update the thread with the current codes tomorrow, but in the meantime I'd be interested in any thoughts and suggestions

[Mart5in]

Could be the ABS ECU. the communication can come up even with a working ECU, it only takes a moment for a failed signal packet to log a code. the ABS ecu is the last place you should look, check all the simple things first. Worth mentioning you cannot check the ABS sensors with a generic multimeter either. :)

But I had a similar problem and both my ABS front sensors had died.

The front passenger one had been hit by the ABS ring (due to a wheel bearing being worn) and the other one just needed unplugged and plugged back in after spraying it with contact cleaning spray.

I had mine into a dealer, since I personally know one of the techs, he tells me on these P2 that the only thing that goes wrong with the ABS 9 times out of 10 is ABS rings rusting and breaking or the sensor failing. ABS ECU failure is rare on the P2. earlier ones suffer badly from cracked terminals where they are soldered.

I got 2 sensors from my local scrapyard for £5, I cleaned the ABS rings with a thin screwdriver, and it's been fine ever since.

That's my thoughts anyway!

[greenspider]

Well, I took it back to get the codes read again the following day, and the abs ecu refused to communicate at all. he tried several times but it was having none of it. The previous day it had taken a couple of attempts aswell. I've just removed the ecu and will get that sent away to be reconditioned, once that comes back I'll see if the sensor codes come back up and investigate further if necessary.

A couple of the engine codes came back up aswell, cam reset valve and long term fuel trim, so I'll have to look into that

[Wobbly Dave]

I can still fix ABS ECU if you need it

[greenspider]

Hi dave. How much do you charge? Does your work come with a warranty? Are you a trader?

[Wobbly Dave]

not much - no but I have repaired over 300 units with 99% success rate - nope but I have been around a while.

[greenspider]

Yes I saw from your post count you have been around a while. I'm just cautious of sending parts of my car along with money to people I've never met that present themselves on the internet, I'm sure you understand. I could do with a bit more information on the cost though Dave. Not much could mean something very different to both of us.

[Wobbly Dave]

If you need people to vouch for me then just ask the wider community. I used to do the fix as part of a partnership with HLM in Bromsgrove & it is still possible to use that route & get a 12 month warranty, however I know it will be more expensive.

[CAMO]

Volvo ABS ECU are a common failure!!! Mine being repaired as we speak!!!

[Dan H]

I'm in teesside and im actually breaking a 1999 v70 2.4 Non turbo, I have abs pump/ecu and everything there if its any use to you? Just drop me a pm as im not on here very often

[greenspider]

If you need people to vouch for me then just ask the wider community. I used to do the fix as part of a partnership with HLM in Bromsgrove & it is still possible to use that route & get a 12 month warranty, however I know it will be more expensive.

That was kind of my point Dave. I just wanted to weigh up if whether it was worth asking you to do it for me, or possibly paying more to have a warranty on it, but I still dont have an idea how much you charge.

[jdavis]

Dave is well respected on here and i'm sure there are many that will vouch for his work.

[Redbrick]

Dave is well respected on here and i'm sure there are many that will vouch for his work.

Indeed but Dave still hasn't stated a price! One man's 'not much' is another man's 'too much'.

I'd PM Wobbly for an answer.

[Wobbly Dave]

Not worth me doing it for less than 60 quid. If you want the warrantied repair then this can be done through HLM Bromsgrove. I have no idea what Hamish is charging these days.