ABS light on, MOT fail ?

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The ABS light on my 05 Renault Master came on and off a couple of times just after going through some big puddles. It's now on all the time. I had a look at the sensors and their connections for the front wheels yesterday and wire brushed the rotors, no better. Obviously I need to check the back two next. My mot is due next month, will this be a fail ?
Is it worth taking it to a main dealer to get the fault codes read, would it show anything up ? I don't think those bluetooth code readers you get on ebay do braking systems, only engine codes ? I'd like to do any repairs myself, within reason.
TIA, Graeme.
 
The ABS light on my 05 Renault Master came on and off a couple of times just after going through some big puddles. It's now on all the time. I had a look at the sensors and their connections for the front wheels yesterday and wire brushed the rotors, no better. Obviously I need to check the back two next. My mot is due next month, will this be a fail ?
Is it worth taking it to a main dealer to get the fault codes read, would it show anything up ? I don't think those bluetooth code readers you get on ebay do braking systems, only engine codes ? I'd like to do any repairs myself, within reason.
TIA, Graeme.
I have heard that it is now a fail.......However, if it's disconnected for the test, then they cant fail it, under the 'not required, but if connected must be working' rules.
 
a code reader not only does engine codes it will read all codes that are stored on the ecu and will will show which wheel censor is faulty,simply get the code and google it,also check the reluctor rings for crack's as a cracked reluctor ring will show as a faulty censor.
 
Yep if the abs light is on it will fail, do exactly what you are doing and clean the sensor/ check the leads and connectors plus clean the rotors,
You shouldn't need. Main dealer to read the codes any decent size garage should be able too and pinpoint the sensor that's gone down if your cleaning doesn't meet with success,
Taking battery off line wouldnt clear a abs fault code

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A fail! Is that true? My ABS hasn’t worked for years and the car always sailed through the test. I suppose that I’ll have to have the damn thing fixed now.

O bother!
 
My van failed on the ABS light being illuminated a few years ago. Fault was intermittent but eventually traced to a wire rubbing on the loom behind the nearside headlamp, this is on an X250 chassis.
 
ABS units, or at least some of them, can be repaired, if that is traced to the fault. It will cost the odd hundred or two but a new unit could be a £1K or more unless you can get one from a breakers.
 
Unfortunately some of the latest ABS ECU are coded to the main ECU to gives us things we always needed but didn't know,
Like Traction control/stability control and tyres being under inflated so you cannot just pop on one from the breakers and expect it to work,
But Devon beekeeper has the right idea about prices!
 
The MoT checks for correct function of the ABS warning light. It must illuminate for few seconds when the ignition switch is turned on then go out.

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Our 1998 Honda Civic went to the great car park in the sky due to an ABS lamp issue. It had come on and off for a few years, and I managed to get a a couple of MOT's in the off stage. However it then moved to permenantly on and that led to a fail. The fix cost was more than the car was worth so we decided it had to go. A great shame as in all other areas it was still a great car that went well.
 
Thanks for all the replies/suggestions. Still got a couple of things to check out but am aching from rolling about under it yesterday. Going to have to get myself a 3 ton trolley jack to make life easier (y)
 
Hi, you say it started after going through some puddles, this could indicate that its moisture in the electrics thats the problem. If youve cleaned the sensors and rotors and still have problem, check the plug connectors, usually just inside engine compartment near to wheelarch, trace wires from sensor, through inner arch to engine bay, 2 wire plug connection will be about 10" higher than entry point. Seperate the plug connectors, clean and spray with WD, disperses water/moisture and refit. This may well sort it.
I had same problem with a vehicle, intermittent abs light and found it to be the plud connector bad connection that didnt like wet conditions. (y)
 
As has been said the MOT test know includes looking for dashboard lights that should light, and its a failure if they don't. So no good removing the bulb for one that stays on.

Ian

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Wheel sensor most likely.
Have it read, and not all readers will do it.... EOBD readers only WONT read it.
Been a failure here in Ireland for about 5 years and it's a regular repair in the workshops.
 
Land Rover Discovery owners do this all the time!

The main faults are:

Loss of signal from any wheel sensor
Incorrect signal from any wheel sensor
Signals not matching.
Shuttle valve switches in the ABS Modulator
Wheel bearing failed giving too much wheel play and thus the gap between the sensor and toothed ring varies.

Most cars have similar systems, albeit you cannot swap modulators between different cars, or rarely anyway.

Sensors are a magnet with a coil wound round its body. Rotating a toothed ring (reluctor ring) past the end of the magnet induces a signal in the coil which is passed to the ABS ECU.

Of the regular faults, wheel bearing play and sensors with rust particles across their faces are the most common.

Sensors can be removed, cleaned and refitted.

Broken sensor cables seem to happen a lot, not sure why.

Shuttle valve switches are in the ABS modulator valve block. Land Rover sell a kit for £40 or so which is a new set of switches and their mounting plate, don't know about other makes.

Water in the connections to the sensors will short out the signal, which is pretty weak anyway.

I'd look at wheel bearings and sensors first.

Peter
 
a code reader not only does engine codes it will read all codes that are stored on the ecu and will will show which wheel censor is faulty,simply get the code and google it,also check the reluctor rings for crack's as a cracked reluctor ring will show as a faulty censor.

Only if you part with megabucks Chris.

£30 OBD readers only do engine fault codes.
 
As has been said the MOT test know includes looking for dashboard lights that should light, and its a failure if they don't. So no good removing the bulb for one that stays on.

Ian
Depends on the manufature year.
some lights are allowed...my 2007 Chrysler had the tyre pressure light on, not a fail due to year.
i believe its post 2012 vehicles that will fail on any light.
ABS will be a fail regardless of year.
 
Thanks for all the replies/suggestions. Still got a couple of things to check out but am aching from rolling about under it yesterday. Going to have to get myself a 3 ton trolley jack to make life easier (y)
And some heavy axle stands i hope.

NEVER rely on a jack alone...even a new one.

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Only if you part with megabucks Chris.

£30 OBD readers only do engine fault codes.
not true john! i have both a cheap code reader and an all singing all dancing one and they both read all codes stored on the ecu,the cheap one you have to get the code and refer to a booklet or google for the code meaning,the all singing all dancing one has its own display which tell's you the code problem in full.will also reset service lights,and airbag warning lights.
 
Been looking at a few clips on Youtube and now know what readings to look for with my multimeter. Checked the connectors on the front wheels and they were perfect, the contacts looked to be gold plated too. Will check the back ones at the first dry weather opportunity.
Have 3 ton axle stands and I'm using the 4 ton bottle jack that I keep in the van from when I ditched the supplied scissor jack, trolley jack should be here Tuesday (y)
Got any details on the cheaper code reader Chris, the ones I looked at only did engine parameters.
 
Harumph - my Xsara failed the MOT test in 2008 because the ABS light didn't come on, we spent £400 trying to get it repaired to no avail. The Citroen dealers couldn't repair it either. So we had to scrap it.

I loved that car.
 
Not suggesting you do this but I knew someone who had a Granada years ago that the abs light stayed on and it failed the MOT. Simple solution was he rewired the light to the glowplug light. Simples and cheaper.
 
Not suggesting you do this but I knew someone who had a Granada years ago that the abs light stayed on and it failed the MOT. Simple solution was he rewired the light to the glowplug light. Simples and cheaper.

not that I've ever done it either :whistle: but there's quite a few ways around it. It's only a bulb that has to come on then go off.

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Not suggesting you do this but I knew someone who had a Granada years ago that the abs light stayed on and it failed the MOT. Simple solution was he rewired the light to the glowplug light. Simples and cheaper.

Ooh that's sneaky but it's always good to have a plan B :D
 
not true john! i have both a cheap code reader and an all singing all dancing one and they both read all codes stored on the ecu,the cheap one you have to get the code and refer to a booklet or google for the code meaning,the all singing all dancing one has its own display which tell's you the code problem in full.will also reset service lights,and airbag warning lights.
Ok, so main dealers no longer have to spend £5000 plus on a dedicated Manufacturer code reader.
most codes other than generic engines codes are specific to every manufacturer.....the same code can mean different things to different cars.
the ONLY reader capable of reading chassis/brake codes on my Chrysler is a factory programmed STAR-TEC unit.....and most, if not all, marque's are the same.
 
Got a make and model number for your cheap one Chris, i would be interested in reading the spec.
 
Ok, so main dealers no longer have to spend £5000 plus on a dedicated Manufacturer code reader.
most codes other than generic engines codes are specific to every manufacturer.....the same code can mean different things to different cars.
the ONLY reader capable of reading chassis/brake codes on my Chrysler is a factory programmed STAR-TEC unit.....and most, if not all, marque's are the same.
rubbish john sorry,dont know about your chrysler but my code reader will read and diagnose most marque's although i did have problems reading my toyota hilux codes,but that was more to do with a connection issue than the code reader.
i have the earlier version of this one.this covers all systems and most cars including yours.

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just looked on ebay for my code reader.i paid nowhere near that price but iv had it 5 years.
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