Ford Scorpio Forum - Print Page


    
      
        Ford Scorpio Forum
        (https://www.fordscorpio.co.uk/cgi-bin/yabb/YaBB.pl)
      

        General >> Problems >> ABS Problems?? Please help
        
(Message started by: ro284 on Jul 4^th, 2009, 2:49pm)

Title: ABS Problems?? Please help
Post by ro284 on Jul 4^th, 2009, 2:49pm

Hi Guys, have a strange fault! when braking to slow the car down (not too heavily) i get a noisy vibrating through the pedal. if i push the pedal harder, i seem io have less braking power, as if i lose servo assistance momentariliy, i notice that the driver side front wheel skidded on its own, when the brakes were not full on! it's a 98 Scorpio 2-3 estate, Any advive for a baffled owner Please?
Cheers Bob

Title: Re: ABS Problems?? Please help
Post by Highlander on Jul 4^th, 2009, 4:13pm

Is it happening all the time?

Does your ABS light come on when it happens?

The ABS module tests the solenoids and if you are braking at the same time you will get the same thing as you have described but you shouldnt feel it very often

Check your tyres pressures..

And tyre sizes just in case you have one different ;)

Title: Re: ABS Problems?? Please help
Post by Tompion on Jul 4^th, 2009, 4:24pm

If a wheel is skidding (or attempting to skid) then you would expect to feel a vibration through the pedal as the ABS tries to control it.
What speed is this happening & what’s the road surface like?

Title: Re: ABS Problems?? Please help
Post by ro284 on Jul 4^th, 2009, 5:24pm

Thanks for replies, it is not happening all the time, but it is a bit alaming when it does, the abs light does not come on when it does it, it is very noticible.
Tyre pressures ok and tyre/wheels all same sise. the front drivers tyre skidded a couple of times at low speed just as i was sweeping in to a parking space, not on full lock, i am aware of the normal slight vibration with abs but this is very pronounced and seems to relate somehow to that wheel,
Thanks Bob

Title: Re: ABS Problems?? Please help
Post by Highlander on Jul 4^th, 2009, 6:01pm

Weird one,

If its doing it at the same place under the same conditions
eg a braking turn at slow speed I wonder if its a sticking caliper or wheel bearing/warped disc causing it.

Is it only happening on one side? either a left or a right turn?

Title: Re: ABS Problems?? Please help
Post by Tompion on Jul 4^th, 2009, 7:58pm

You could disconnect the ABS to test whether it’s what Highlander suggests, but probably not much use if intermittent.

Have you cleaned the sensors & sensor rings? It could be losing the signal from 1 sensor at low speed.

I’ve had a similar problem at very low speed (below 5mph at a guess).
In my case it was too big an air gap with a rear sensor. At some stage presumably when a bearing had failed the sensor had come into contact with the sensor ring & had about 1mm ground of the face of the sensor.

Just guessing, but I assume there’s a threshold speed (T) at which the ABS stops working & my sensor was losing its signal at say T+1.
When I approached a junction with very little braking, when the speed reached T+1 the ABS cut in on the rear wheel at which point I didn’t think I was going to stop so I pressed harder on the brake, the speed by then was down to T & a wheel locked (not necessarily the one with the faulty sensor).

That is my thoughts on what probably happened, but it felt like the ABS was cutting in, a wheel was locking & I wasn’t stopping all at the same time.

I think in my case it only happened with very light braking & sometimes the light would come on.

I know it’s the front locking, but look at the rear sensors, the faces should be flat – if one is concave then it’s rubbed on the sensor ring.
In fact both of mine had rubbed & were concave but one was shorter. When I modified it to reduce the air gap the problem went away.

Title: Re: ABS Problems?? Please help
Post by ro284 on Jul 4^th, 2009, 9:23pm

Thanks for your time guys, a bit more info having driven a long way now! if im doing a good speed say 50-60 to test for this fault and put the brakes on firmly, she pulls up fine, no problem, the strange bit is if i keep the pressure on, its when the speed is reducing to 20 mph there is a phut! and a vibration on the peddle which goes right down to stop, so it seems what ever speed i am braking from as soon as it hits 20, that is when the problem starts. juddering pedal and wheel trying to let go!
Cheers Bob

Title: Re: ABS Problems?? Please help
Post by Tompion on Jul 4^th, 2009, 9:53pm

If you can consistently get the symptoms then unplug the ABS multiplug or pull the ABS fuses & see if it still happens.

An ABS scan may help

Title: Re: ABS Problems?? Please help
Post by wojtekor on Jul 4^th, 2009, 10:24pm

abs module is failing... ::)

Title: Re: ABS Problems?? Please help
Post by ro284 on Jul 4^th, 2009, 10:38pm

abs module is failing...??? do you think thats what it is
Wojtekor? have you had this problem? Thanks

Tompion i will try the multiplug to tomotow to see what happens!
Is an ABS scan a dealer job? ive not come across anything like ABS problems before,
Also where is this module Please?
Cheers Bob

Title: Re: ABS Problems?? Please help
Post by Tompion on Jul 4^th, 2009, 11:57pm

I had considered the module or the valve block, but with it occurring at 20 & below, whilst I wouldn’t rule them out I’d be surprised if it was the problem.

You can get a scanner, but you need to be sure it can read ABS. Some of us have a lead from http://www.obd-2.com/ that can read ABS (I should mention that there are a few later 2.3’s that can’t be scanned with these leads).

Whereabouts are you, someone may be able to do it for you.

If you click on the pictures here:
http://www.fordscorpio.co.uk/absmodulator.htm

This shows the older style control block, the modulator is underneath.
The later control block has the controller in front.

I would also carefully check the disks and pads for damage.

Title: Re: ABS Problems?? Please help
Post by ro284 on Jul 5^th, 2009, 12:34am

Brilliant Tompion, many thanks for that, well i don't have a scanner but willing to get one, if it will help, i have just looked under the bonnet, and it looks to me as though the module is mounted on the front, so maybe the scanner will not work on mine, i live in Christchurch. Dorset, by the way, in the morning i will have a look at the wheel/brake sensors etc, to see if i can find any obvious problem,
Thank again Bob

Title: Re: ABS Problems?? Please help
Post by Tompion on Jul 5^th, 2009, 12:44am

It’s not the type of ABS fitted that prevents some 2.3’s from being scanned.
My 2.3 has the later type of ABS & can be scanned with my tricom lead from http://www.obd-2.com/

Title: Re: ABS Problems?? Please help
Post by ro284 on Jul 5^th, 2009, 10:19am

Thanks again for your help and this link, ttp://www.fordscorpio.co.uk/absmodulator.htm did cleaning all this out solve the problem? i guess i need the scanner but i would find using it to highlight the problems difficult, i am pretty handy with a spanner.not so sure about scanner! so i wonder if there is somewhere i could take the car, to scan it for me? i wonder if it would be easier to change the unit, which i imagine would be very costly. and difficult to justify the expense for an 11 year old car.if there was someone in Dorset who vcould say its this or that part change it, that would be great! or its either the abs or the module, can each of these be changed independant of the other?
cheers Bob

Title: Re: ABS Problems?? Please help
Post by Tompion on Jul 5^th, 2009, 12:11pm

Having thought it over some more, a scan may not reveal anything, as the ABS light doesn’t come on there probably aren’t any codes.

If there were any codes you would need to scan it twice – once to clear the codes as they may be from a previous problem & again after the problem occurs.

Since you say it occurs at 20mph & below, I think that rules out the problem I mentioned of a lost signal caused by to big an air gap on a sensor, as it would have failed the rolling test after start up that occurs at approx 15mph (the ABS light would come on).

The modulator, control block & pump can all be changed independently.

I think careful inspection of the disk, pads & calliper as Highlanders suggests is worth doing.
There have been reports of pieces breaking from the disk.
Also the webbing in the vented disks can rust to such an extent to weaken the disk.

Title: Re: ABS Problems?? Please help
Post by gozz on Jul 5^th, 2009, 12:21pm

ro284.
There is a bloke in Bournemouth,a participant on here who is dismantling his 2.3,'Stafford' is his name,look back at previous parts for sale posts,there was something in my mind relating to him and a scanner,don't know if he was selling one or wanting one.Send him a PM,he may see it.
GOZZ.

Title: Re: ABS Problems?? Please help
Post by ro284 on Jul 5^th, 2009, 1:04pm

Many thanks GOZZ,That could be helpfull. Do you know roughly how long ago Stafford was advertising this,
Cheers Bob

Title: Re: ABS Problems?? Please help
Post by wojtekor on Jul 5^th, 2009, 3:30pm

on 07/04/09 at 22:38:40, ro284 wrote:

abs module is failing...??? do you think thats what it is
Wojtekor? have you had this problem? Thanks

me personally no, but the symptoms you described are filed on the polish forum under FAQ abs module failures. unfortunately the only cure seems to be changing the module itself together with the abs pump.
i don't know why but on the polish forum they seem to have quite a lot ABS problems, so I've read about them all. Some specialists say that it's due to very poor roads in poland.

Title: Re: ABS Problems?? Please help
Post by Highlander on Jul 5^th, 2009, 4:24pm

on 07/05/09 at 15:30:46, wojtekor wrote:

Some specialists say that it's due to very poor roads in poland.

They should come to Ayrshire!! }{

Title: Re: ABS Problems?? Please help
Post by ro284 on Aug 18^th, 2009, 6:11pm

Sorry no reply before now, the problem remains, however, i found the diagram of the connections Teves
20 wheel sensors ABS PLUG, (probably from tompion) very helpfull in as much, that i have got some readings with a multimeter, as follows==
RR=01.1
FR=01.1
RL=01.1
FL=27.3 fluctuating constantly to 30.3
Please note the Meter set to 200k ohms! Could this be a clue?
Thanks Bob

Title: Re: ABS Problems?? Please help
Post by Tompion on Aug 18^th, 2009, 6:33pm

You need to separate the front left sensor plug that's in the front wing, clean it and check the resistance to the sensor directly. If you still get the same reading you probably have a faulty sensor.

If the reading is now the same as the other sensors & stable plug it back in & test back at the controller plug, if it’s still wrong or fluctuating then you need to check out the wires and connectors from the controller to the sensor plug.

Title: Re: ABS Problems?? Please help
Post by ro284 on Aug 19^th, 2009, 1:56pm

All done! Huge thumbs up to Tompion for all the help advice and diagrams! ;D it was not the abs module failing! which was my major worry, With the diagram i was able to pin point the bad connection and rectify it, all with a multimeter! i never did managed to get a scanner,
Anyway no more abs light, no juddering, Thanks again to everyone who replied,
Cheers Bob

Title: Re: ABS Problems?? Please help
Post by Tompion on Aug 19^th, 2009, 5:33pm

Glad to hear it's fixed :)

Title: Re: ABS Problems?? Please help
Post by PJDavis on Aug 19^th, 2009, 5:58pm

This forum is so helpfull. I've read through this thread to familiarise myself with the problem and what fantastic feedback from Tompion! I'm a bit old for these more modern cars, when I did my apprenticeship on Zodiac / Zephyr Mk 4's and really I'm more 'hands-on'. I'm kind of going through a repeat "I want big Ford" life, even though I still have a Mk4 Zodiac Executive. I hope I can eventually be of use to this site regarding mechanical repairs but currently my Scorpio is running great.