Abs warning light

[KennyW]

Good Evening,

The abs warning light has been coming on and going off for the past week. It even stayed off for 48hrs.

No noticeable difference in braking but due to the slightly inclement weather had no chance to investigate and thoughts would be appreciated.

Kenny

[citroenxm]

Abs light on wont affect ordinary braking in the slightest UNTILL you do an emergency stop and your wheels lock up

that all the abs does. Prevent wheel lock up in a panic and help maintain grip.

it could be one of the sensors. it could be a relay .. if theres a lexia owner nearby get a reading and therefore a better answer to the cause of the light on.

[Hell Razor5543]

If you have a multimeter it is possible to check the sensors very easily. This post has the relevant pins and resistances to look for;

http://www.frenchcarforum.co.uk/forum/v ... hp?t=26012" onclick="window.open(this.href);return false;

Hope that it is a front sensor that has failed. All being well you can swap the sensor within an hour. The rear sensors are a lot more inaccessible, and might need a blowtorch to get the bolts to let go.

[harryp]

If the light is going on and off as stated, my guess is that it is more likely to be a dickey plug. Agree with Hell Razor in that first port of call is to check resistances at the ABS computer plug. Then open and clean the respective plug and socket....??

[Hell Razor5543]

It could also be a reluctor ring. This is a castellated ring that is on the drive shaft (the rear ones are an integral part of the wheel hub), and over time the metal under the ring rusts, expands, and then causes the ring to crack. As a result, it is no longer tight on the drive shaft, and therefore can spin at a different speed to said shaft. The most likely times for this to happen is either when you are slowing down quite hard, or at high speed. I had both fail on Gracie, and replacing them sorted out the ABS.

EDIT; Gracie is about a year younger than your Xantia, so it is possible one or both of your rings are the cause. These are the rings I got;

http://www.ebay.co.uk/itm/CITROEN-XANTI ... 27c0132920" onclick="window.open(this.href);return false;

[KennyW]

Thanks for the replies,

I have a mutlimeter so I could check the voltages. I do have a new front Abs sensor which i think i'll fit anyway.

I changed the one of the front CV joints last year so its fine.

James the reluctor rings are a possibility as this is definitly affect by speed. The sensor light switched off shortly after leaving work and did not come one all the way home. I didn't go above 60mph. But travelling into work the light went off and at 70 mph the light came back on.

I suspect the ring can be affected by road surfaces as well because at low speed the light came on as well.

Kenny

[RichardW]

Got a Lexia here now if you want to interrogate it Kenny

[Hell Razor5543]

That sounds very like the problem I had when Gracies' reluctor rings failed. If you don't have quick access to a Lexia I would lift the car fully up on the suspension, turn the steering to a full lock position, and then see if you can find the reluctor rings, and if they are loose. It is not a tricky problem to fix, but the most likely problem you will have is loosening the hub nut, as it probably has not been undone since the car left the factory.

[harryp]

Kenny,
Do let us know how you get on with the cause and fix!! Ta.
Kind regards, Harry

[KennyW]

Richard,

A lexia session would be great, the good news for me I'm off until Wed 21st January. Just let me know the best time and date and I can drive over.

Harry, will keep everybody posted.

Kenny

[RichardW]

Nice to meet Kenny this evening

Typically light was off all the way over, but Lexia reports intermittent coherence fault and intermittent OSF sensor fault.

Engine looks to be in fine fettle though - rock steady fuel pressure at idle at exactly the right pressure, and minimal injector flow corrections. Looks like it needs a new crank pulley though....

[KennyW]

Nice meeting Richard last night and had a look at the ABS problem,not the best weather for looking underneath a car. Must say thanks again on the forum and it is always nice meeting other members.

The trip back was enjoyable and the light didn't appear on again .

Had a look very briefly today and nothing obvious. I readjusted the routing of the cable and loosened and retighten the securing screw to sensor on caliper. Drove to friends garage and back still no light on.
This was the side I changed the cv joint on last year and the sensor cable.
I suspect that this may be a cable routing problem as one of the holding brackets is missing worth replacing at only $7 from citroen, probably an issue with the gap between sensor and ring.

It is just too cold to do any serious work on the car at the moment and the list is mounting.

Have seen the lexia in action I may purchase one myself.

Kenny

[c.morewood]

Just had the same problem Kenny.. why does it always happen at the worst times? (-7 outside and car covered in salt which you can't wash off!!)
I've just checked everything out underneath after having the same Lexia and light fault.
The ABS light will go out after you get above, I think its 15 mph, if it thinks the fault has cleared.
I'm pretty sure mine is just the sensor after cleaning up the reluctor ring and the sensor as well as fiddling around with the connector for half an hour trying to get it back together one handed.
I see they're quite cheap on EBay.. from £7.50 upwards.

[KennyW]

Just drove the car today to take my mother shopping and no light came on.

Kenny

[c.morewood]

I've discovered that my light goes off after getting above 10 mph... However that's when things get a bit interesting, as after the light goes off the ABS kicks in every time I brake to a stop , giving the effect of being on ice.. so I'm leaving an extra long gap at the moment till I get the replacement sensor... BUT when the light is on I have normal braking, allbeit without the ABS.. Very strange.