MOT and ABS question

[Jaf]

Ok so this is 3rd hand...a friend's kid has a xantia with ABS. When he gave her the car the ABS light had been on a couple of years, his mechanic said he disconnected it but he just stuck a sticker over the light, then it passed the MOT a couple of times. Mechanic quoted £1000 to fix it, sending away a computer, but wouldn't recommend it as he said the fix might not last?!? So it's had the ABS problem for 4 years.

Now the kid has taken it for MOT, failed on ABS. The new MOT place says now it has failed for ABS it must be fixed as any subsequent MOT will check the ABS as it's registered on MOT computer. So I guess she can't take the bulb out. I would be tempted to try somewhere else but that's no good if they really do check on the computer.

Obviously the car's not worth a grand fixing. I know nothing about ABS. Anything easy to check? I'm in Spain, they're in UK so it won't be me doing it!

Oh yeah the MOT place said they could continue to drive for a week on the old MOT. I thought once it failed you couldn't drive?

[xantia_v6]

I think that tape over the ABS warning light was always a fail, as the tester should be checking that it flashes correctly on startup. Airbag warning lights could (until last year I think) legally be covered by tape.

An open circuit wheel sensor can be detected by measuring the resistance, but any other diagnosis really needs to be done with a Lexia code reader.

[Hell Razor5543]

There are several reasons an ABS system can fail. The first things to check (using a multi meter) are the sensors themselves. The following link explains how to do this;

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

and it has the pin outs for both S1 and S2 Xantias.

[chinkostu]

I got told mine might be the abs ecu dying, two new sensors and it works beautifully.

Theres a pin out somewhere that you can use to measure the sensors using the ecu multiplug, thats how i found mine was the front two.


Does the abs light flicker at all when you turn the ignition on?

[Jaf]

Yikes. Glad I don't have ABS! Not sure the fella even has a multi meter. Will talk to him in the morning. He's muttering about buying her another car, a fiesta, for £1600. But a car that cheap is bound to have problems too.

Thanks!

[turbom]

Have a look on the drive sharft first to make sure the trigger ring is there my picasso had a abs fault brought 2 new sensors and found the trigger ring had broken £1.40 off ebay. Was very lucky it was a easyish fix.
I know on commericals and psv"s if they had abs it had to work.So when vosa use to come and mot the vehicles they would drive them around the yard to make sure the abs light went out.

[mad_at_french_cars]

Ok so this is 3rd hand...a friend's kid has a xantia with ABS. When he gave her the car the ABS light had been on a couple of years, his mechanic said he disconnected it but he just stuck a sticker over the light, then it passed the MOT a couple of times. Mechanic quoted £1000 to fix it, sending away a computer, but wouldn't recommend it as he said the fix might not last?!? So it's had the ABS problem for 4 years.

Now the kid has taken it for MOT, failed on ABS. The new MOT place says now it has failed for ABS it must be fixed as any subsequent MOT will check the ABS as it's registered on MOT computer. So I guess she can't take the bulb out. I would be tempted to try somewhere else but that's no good if they really do check on the computer.

Obviously the car's not worth a grand fixing. I know nothing about ABS. Anything easy to check? I'm in Spain, they're in UK so it won't be me doing it!

Oh yeah the MOT place said they could continue to drive for a week on the old MOT. I thought once it failed you couldn't drive?

It's correct that it's registered on the computer, but it's not a massive problem. Unless it's the ECU, which I believe is rare, any local Citroen independent should be able to fix it, probably for less then £150 - that's including an hours labour and a couple of sensors. Less if it's simply a trigger ring.

EDIT: HINT - in the UK, I find it's often the nearside front sensor that's failed. I imagine this is because it's the first to come into contact with road grime and get jarred by potholes.

[wheeler]

If it is the ECU thats failed then what you need is a wiring diagram for the ABS system & a wiring diagram for the oil pressure warning light, I'll leave the rest to your imagination.

PS an mot is valid until it expires regardless of the results of any test after it is issued, however having a valid mot doesent excuse you from driving a dangerous or unroadworthy car.

[macplaxton]

I think that tape over the ABS warning light was always a fail, as the tester should be checking that it flashes correctly on startup.

Yep

Method of Inspection
3.4.1. If the vehicle is fitted with an ABS and/or ESC system, check that the relevant warning
lamp(s):
a. is fitted
b. illuminates
c. does not indicate a fault

Reasons for Rejection
3.4.1. A warning lamp:
a. is missing
b. does not illuminate
c. indicates a fault

Airbag warning lights could (until last year I think) legally be covered by tape.

Wording on that is still:

Method of Inspection
5.4.2. Check that the Supplementary Restraint System (SRS) malfunction indicator lamp (MIL) does not indicate a fault in the system.

Reason for Rejection
5.4.2. A Supplementary Restraint System (SRS) malfunction indicator lamp indicating a system malfunction.

Explains the train of thought of the missing SRS lamp: https://mattersoftesting.blog.gov.uk/co ... t-testers/" onclick="window.open(this.href);return false;

Until they change the wording to be like that of the ABS light, I'd still say that the above info on the SRS light applies.

Whatever you do, don't turn up for test with one of these

[DickieG]

Whereabouts is the Xantia in the UK? There are a number of members on this forum who offer diagnostic checks using Lexia, the Citroen diagnostic tool which will provide quick/accurate diagnostic information rather than wasting time/money stabbing in the dark.