Abs system faulty

[NewC5dude]

Hi everyone, just returned home for a 90 mile trip today. On way home ABS light came on a beep. Says ABS system faulty. So it turned off ESP and also ABS light and ESP light stayed on the dash. There was no change in braking/driving experience. Am i right in saying these have the same issue as the clios with the toothed rings for the speedo? Or anyone had the same problem?

[NewC5dude]

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[c5ted]

im going through the same thing

a diagnostics should tell you where the problem is

[NewC5dude]

Just been out for a short drive around 4mile round trip. It never came on at all, so i am thinking maybe a sensor(maybe dirty) had the same problem on my clio, turned out to that toothed rings think it is to measure speed? Not sure exactly what the garage said but changed both side of them and ABS light went off.

[NewC5dude]

It was called the ABS sensor ring

[RichardW]

What engine is in it?

[NewC5dude]

2.0 VTR HDI+NAV

[Doo]

I was having the same issue with My Range Rover and the intermittent soon became always on

Anyway, I took the front hub apart and it turned out the reluctor ring had rusted, swelled up and split which is pretty common no matter what type of vehicle you drive. I was able to order & fit a new CV joint complete with ring for under £30.

The reluctor ring turns with the drive shaft and produces an induced alternating voltage. The teeth on the ring interfere with the magnetic field (make & break for each tooth and each gap) which is picked up by the sensor and it can tell if one or more wheels is stopped (locked up under heavy braking) and thus sends a signal to the ABS module which rapidly opens & closes a valve in the block to allow the wheel to brake and release rapidly (that's when you get the chatter off the pedal in snow for instance.

If your ABS light is on, the pump is switched off and normal braking is still enabled and you can then lock up the wheels under heavy braking.

If you are pulled by the plod, they "could" book you under construction & use. But if you were to have a crash and the ABS was found to be inoperative, you WILL be charged and heavily fined and your insurance "may" be null and void. In other words, get it fixed ASAP. My wife's C4 was off the road for 2 months until I got LEXIA found the cause. Other code readers wouldn't communicate with the ABS systems so it was safer to let her drive the spare car.

[Hell Razor5543]

Please be careful. If the ABS system has any semblance to that on a Xantia it could be dangerous. On a Xantia, if the car is moving when the ABS throws an error, the brakes will NOT work for a few seconds while the ABS system evaluates what has happened. If this happens under braking it makes things interesting for all concerned. I know, it happened to me (as one of the reluctor rings was no longer tight on the drive shaft, so it was turning at a rate different to the other three rings, which threw up an error). Fortunately it happened on an empty straight road with enough room to allow the brakes to come back on line.

[NewC5dude]

When the error appeared i did a brake test was only doing about 25mph when the code came up. I tested the brakes every so often on the way home and was cautious all the time. It has not not appeared up today at all

[xantia_v6]

Also be aware that some modern vehicles don't have separate ABS reluctor rings, the teeth are integral to the wheel bearings.

[NewC5dude]

Yeah i read that somewhere, thanks for the quick responses, will get it looked at tomorrow hopefully. But looks like it is all pointing to ABS reluctor rings.

[Doo]

Also be aware that some modern vehicles don't have separate ABS reluctor rings, the teeth are integral to the wheel bearings.

I was going to post that, but I thought I may sound a bit "annoying dad"

I recall telling my boss to get ONLY Renault rear discs for a customers car, but would he listen?

The car rolled off the ramp with a live ABS lamp... "Try it and if it doesn't go off, come back tomorrow...!"

He came back, I ordered original discs from Renault and had them fitted within minutes of delivery. The ABS light was off by the time it came off the ramp and up to reception

Those type of rings work slightly differently, but the end result is the same

[van ordinaire]

When I got the red Cherokee the ABS wasn't working but I didn't know because there was no light (or so I thought), I've never learned to change my driving habits to rely on it & it's an option on these, at least in America. There was one horribly distorted reluctor but changing the 1/2-shaft made no difference (nor did refitting the fuse & relay); turned out it was both front sensor leads. Curiously my 1st XJ40 was the same, diagnosis was ECU, changed that, out went the light, only to come on again - 1/2-way to Prague. Back at my local indie specialist we went through a box of leads 'til we found one with the same resistance as the other 3. Moral: if the sensor's not damaged and the connectors are good & clean - it's most likely a lead, but simply replacing it won't necessarily fix it.

[NewC5dude]

Its booked into garage at 2pm today, the ABS is working fine and no lights on dash just hope it pops on before i drop it off.