help needed early 850 abs,reward offered!

[duke1]

Originally Posted by Baffler

Taken from Volvo / Pocket Data Booklet Cars / 850 / Diagnostic Trouble Codes / ABS

141 = Faulty pedal sensor, shorted to ground or supply.
142 = Faulty stop (brake) lamp switch, open circuit or short circuit.
212 = Right side front wheel sensor, no signal when moving off.

Have you tried to delete these codes and see what comes back? I can't remember the erase procedure so maybe someone else can advise how to delete via the engine bay port.

And have you tried the cardboard/wedge trick between the multiplug and module or is it very different on early Alter 2 cars?

Also, given the amount of parts you've changed out I'm wondering if this could be a wiring/multiplug issue and a possible cause for your intermittent 12v supply? You may need to test each wire/connection for continuity and monitor resistance across each one or, at least, open up and inspect the harness for physical damage.

hi i got the code list off mvs forum so i do not understand this at all! if thats the case it makes sense as today i opened the brake position sensor and just like on the thread here it was broken at the solder joint and for just a second i had hope but i soldered it back and refitted but the evil thing is still there.
i drove it a half mile or so after in hopes it would go out but still there.
the brake lights are working fine but as switch is cheap i will replace it anyway,see i intend to keep this car for the rest of my/its life and if i end up with a few extra spare parts esp hard to find ones im happy with that,but theres a limited supply for this early 850 and so many bits cost 10x more than for same part on later 850s and v70s no idea why that is.
i shall look for the source of the codes you found but i did and keeps asking for subscription and card details but says free? any other source to accurate for early 94 850 codes? thank you for reply

[Baffler]

My data booklet covers models 700, 900, S90, V90, 850, S70, V70, C70 from 1991 to 1998 so the codes should be applicable to your 1994 model.

On the 850 it may take 20 miles or more of driving for the light to extinguish plus several stop/start cycles.


I remember using the early flash code system on my 480's, many, many moons ago, but couldn't remember the sequence/procedure. Found the following procedure on Volvo 480 Club Europe (codes not applicable):

After the faults have been remedied and having done two readouts of the fault codes, the memory function can be erased. This is done as follows:

Keep the button pressed in for at least 5 seconds and then release it.

The diode lights up after 1.5 seconds.

Depress the button one more time within 5 seconds and keep it pressed in for at least 5 seconds.

A new readout of test function 1 should indicate flash code 111

Alternatively, if above doesn't work, the chaps in the 700/900 Series General may offer assistance reading and deleting DTCs.

And no need to pay for anything that is freely available to us enthusiasts. Maybe try a different web browser

[duke1]

[QUOTE=Baffler;2916808]My data booklet covers models 700, 900, S90, V90, 850, S70, V70, C70 from 1991 to 1998 so the codes should be applicable to your 1994 model.

On the 850 it may take 20 miles or more of driving for the light to extinguish plus several stop/start cycles.


I remember using the early flash code system on my 480's, many, many moons ago, but couldn't remember the sequence/procedure. Found the following procedure on Volvo 480 Club Europe (codes not applicable):

hi well thanks i think it started to make some sort of sense and i am awaiting delivery of a new brake light switch and an oe used brake position sensor (though i think my repaired one is working as no code for that now) i also found the electrical part of the ignition switch though im not convinced there anything wrong with the original i think it has been replaced possibly in 2005 as theres some invoices for a drivers airbag and ignition barrel but cant hurt to have a spare.
as i had a little time to kill i took all the plastics i have undone and repaired and cleaned them as some heavy handed monkey had been at the dashboard for some reason and broke some of the screwholes clean off thanfully the bit of plastic where still there and some careful use of superglue means it should all screw back properly and get rid of some rattles and squeeks!
i just pray that the brake light switch finally gets the abs evil light out,interesting that it needs to be driven esp as it now has no mot,i hate being unable to use it esp as the cat and one of the dogs need the vet......peace

[duke1]

help!!!!!!!!!!!!!!!!!!!!!!!!!!!! still trying to kill the evil thing (abs warning light) today i fitted a brand new genuine volvo brake light switch and a used but known to be good brake position sensor this cleared 2 of the 3 stored dtcs but i have this now
Right front wheel sensor, no signal on moving off 212 code its the last one but as far as i can see theres nothing broken or damaged on the right front connector and the sensor is new,should i chop off the connector and solder direct to the sensor?
anyone?cheers

[Luxobarge]

Originally Posted by duke1

,should i chop off the connector and solder direct to the sensor?
anyone?cheers

Definitely not, IMHO.

OK, so you're getting there, only the front right sensor issue to sort out now.

The sensor is new but it may still be faulty? By no means unknown...

Also I'd suspect the reluctor ring (ABS ring) - is this new? If so, are you totally sure it's undamaged? Might be worth removing the sensor and inspecting it really carefully, ideally with a bright light and magnifying glass. ANY irregularity or imperfection can cause the problem you're seeing. I've just replaced both of mine, mainly because of an intermittent ABS light, gradually getting worse.

Stick with it buddy!

HTH

[duke1]

hi all well at long last i fixed the evil thing the abs light is out!new mot today so im a happy and somewhat less strssed volvo 850 owner,my neck is killing me now after sodding about upside down trying to fit the new brake light switch.
incidently i did an autopsy on the old brake light switch and found it is a 2 pole switch and has 4 contacts one of those 4 was missing if i had not broken the plastic in order to open it i maybe could have repaired it with a blob of solder where the contact was absent but as it is it now has a new genuine volvo switch and the original brake position sensor i repaired which is now working,skandix wanted £168 for it!im glad i can still solder well.
next up is getting the 4 wheel alignment but garage says it maybe to old and they have no settings for it,anyone know where one could find them? cheers all.

[4x4]

This is for 1995-1996

[Luxobarge]

Oh, your previous post said you still had a left front wheel sensor code? Really happy for you if it is indeed now fixed, what fixed it in the end? Cheers

[duke1]

Originally Posted by Luxobarge

Oh, your previous post said you still had a left front wheel sensor code? Really happy for you if it is indeed now fixed, what fixed it in the end? Cheers

hi it seems the pattern part sensor from intermotor is not quite the perfect fit theres 2 alignment lugs and one is slightly out of alignment so even when you tighten the 10mm nut the sensor sits higher than the original one and so further away from the ring it required a little shave with the fine file and then sat correct and after a drive about half a mile in which the light was on at start then after a few hundred foot it went out,then back on then off and stayed off!cheers.

[Luxobarge]

Excellent, thanks for letting us know. You must be over the moon......