ABS fault - I admit, I need some help now! (406 estate)

[PugLover]

Right I am in desperate need of some advice regarding my long-standing ABS issues.

I noticed the fault the day after I picked the car up (Dec 2011) and I have not been able to rid myself of it since, it is very very intermittent.
I took it to a garage early 2012 when the throttle clip came off and was charged £50 diagnostics for nothing to flag up, only for me to drive half a mile before it came back on.

Okay so, last year to get it through the MOT I had Peugeot Planet diagnostics done on it which revealed it was the rear right ABS speed sensor.
I replaced the speed sensor and cleared all the fault codes with my PP2000.
It stayed off for about a week but then came up as soon as the key was turned (before setting off).
When I was replacing the sensor all the reluctor rings looked in tact. There is certainly no juddering under the brake pedal to even suggest it.

Fault is still very intermittent, sometimes it is upon start up, sometimes it is half a mile down the road, sometimes it's 20 miles later, sometimes it stays off for complete journeys and there seems to be no rhythm or reason as to when it comes on! (It seemed okay in the wet and worse in dry weathers, however recently it appears to have changed the other way round).

I am 99% convinced that although diagnostics still state the fault is with the Rear right sensor that it is some of the wiring to the sensor.
My next port of call was going to be completely eliminate the abs connection box which sits on top of the fuel tank, access is limited though and with an impending bump, fuel tank and soldering iron I don't know whether I can do this myself...

My question is this, are there any known faults within the 406 wiring that commonly break? Also wondering where the wire goes into the car or joins a loom or what ever?
I did notice that when I put the sensor in and connected the box up (near fuel tank) that I put some WD40 in the plug and maybe a week later is when that dried out?
Just speculating really as to be honest, this fault is really beginning to bug me! It's got to go through an MOT in May time and I will be only 4 weeks away from giving birth so what ever I need to do to sort this fault (if I can) I need to do soonish!

Thanks everyone

P.s if it helps, it's a 2001 (semi multiplexed) 406 estate. It's a 2.0 petrol

[addo]

You need to check all wiring runs for continuity/resistance in case there is terminal corrosion on a connector.

I have ABS problems on a Pug, in my case it's either a worn relay on the ABS bloc or the unstable alternator supply which is not allowing the ABS computer's own power feed to "latch" on and stay on. Do you have any flickering to the dash lights, or if you operate a power window with the headlights on, do they momentarily dip?

[PugLover]

You need to check all wiring runs for continuity/resistance in case there is terminal corrosion on a connector.

I have ABS problems on a Pug, in my case it's either a worn relay on the ABS bloc or the unstable alternator supply which is not allowing the ABS computer's own power feed to "latch" on and stay on. Do you have any flickering to the dash lights, or if you operate a power window with the headlights on, do they momentarily dip?

Well, electrics isn't my strong point! I don't have a multi meter and wouldn't even know which setting to use it on or how to use it for a continuity check!
What pug have you got, is it semi multiplexed like mine? Have absolutely no flickering or dipping of lights
Where is the ABS relay in the block? I am convinced it's wiring because of it is very intermittent! It's going to be a right sod to find if it is a very slight break in the wires somewhere the continuity may come through as okay apart from when ever it lights up the fault!

At my wits end now, can you tell?

Thanks for all the advice though!

[citronut]

were did you purchase the sensor you fitted, wasn't that E bunch were it

[Gibbo_Wirral]

My brother had the exact same problem on his 307 estate, his was the rear left.

We traced it back to a slight break in one of the wires at the ABS block.

If you're anywhere near Sheffield I'm sure he'd be happy to try the same thing on yours.

[uncle buck]

...Well, electrics isn't my strong point! I don't have a multi meter and wouldn't even know which setting to use it on or how to use it for a continuity check!

Well you're either going to have to learn or take it to a garage

You can pick up a multimeter for a few quid these days, have a look in Maplins or the likes for a cheap meter.

There's tutorials on youtube showing how to use one, it's not dificult.


Cheers.

[PugLover]

were did you purchase the sensor you fitted, wasn't that E bunch were it

Umm... yes it was...... My bad?

My brother had the exact same problem on his 307 estate, his was the rear left.

We traced it back to a slight break in one of the wires at the ABS block.

If you're anywhere near Sheffield I'm sure he'd be happy to try the same thing on yours.

Thanks for the reply, did your brothers show as a rear right on the diagnostics? A chap at my local MPD did suggest that sometimes the diagnostics get confused and it **MAY** be the opposite side that needs doing...
How did you repair the slight break in the wires? Did you solder it back up or replace the wire / loom?
Sadly no where near Sheffield, I'm down in Oxfordshire!
Will I have to rip the car to bits to trace this fault? Is that what your brother had to do? Thanks in advance!

...Well, electrics isn't my strong point! I don't have a multi meter and wouldn't even know which setting to use it on or how to use it for a continuity check!

Well you're either going to have to learn or take it to a garage

You can pick up a multimeter for a few quid these days, have a look in Maplins or the likes for a cheap meter.

There's tutorials on youtube showing how to use one, it's not dificult.


Cheers.

Thanks.. I guess I will have to learn
Will have a look at multi meters now and see if the pennies allow it... though this past week she's been a good girl and not said the dreaded you know what... it's like she knew I posted this topic

[Hell Razor5543]

You can pick up a multimeter for around £10 that will meet most of your needs. You didn't say where in Oxfordshire, so I found the link for Maplins, Oxford;

http://www.maplin.co.uk/store/oxford" onclick="window.open(this.href);return false;

There is something you might want to try. If it is easy to access, pop open the ABS connector (from sensor to loom), spray a load of PROPER contact cleaner in there (not WD40!), and then put a bit of Vaseline into them before closing it back up. When I had a cheap sensor start to play up I did this, which cleared up the problem for a few months until I replaced the sensor with a decent one.

[PugLover]

You can pick up a multimeter for around £10 that will meet most of your needs. You didn't say where in Oxfordshire, so I found the link for Maplins, Oxford;

http://www.maplin.co.uk/store/oxford" onclick="window.open(this.href);return false;

There is something you might want to try. If it is easy to access, pop open the ABS connector (from sensor to loom), spray a load of PROPER contact cleaner in there (not WD40!), and then put a bit of Vaseline into them before closing it back up. When I had a cheap sensor start to play up I did this, which cleared up the problem for a few months until I replaced the sensor with a decent one.

Worth a try, thanks for the help! Hopefully I can get on top of the problem! Where did you buy a new sensor from and at what cost?
I had to glue the new sensor in because the retaining bolt rounded off and I couldn't get any further with that....

[Hell Razor5543]

That could be your problem. The sensor has to be close to the reluctor ring for it to pick up the changes properly. If you can get a replacement bolt of the right type, I would spend some time using Plus Gas on the original bolt. Not for nothing is it known as "Dismantling Fluid"! Given enough time (typically a daily application for a week) it should help loosen off the bolt. Once you have done so, cleaning up the surfaces is needed to get the distances right.

Just to give you an idea how sensitive the sensor can be, somebody on the forum fitted a new front sensor (on a Xantia) with the heat shield between the hub and the sensor. Only a couple of millimetres from where it should have been, but enough to throw the ABS system. Once they got it right (it wasn't me, honest!) the ABS settled down.

You can get Plus Gas from ECP (wait for Citronut!) for under £10 a can. It does really work, given enough time to soak in.

EDIT; By the way, I have a Xantia, so I don't know how much a sensor would be for your Pug. I got my good (well, they seem to be so far) front sensors off e-bay, at about £30 each.

[PugLover]

That could be your problem. The sensor has to be close to the reluctor ring for it to pick up the changes properly. If you can get a replacement bolt of the right type, I would spend some time using Plus Gas on the original bolt. Not for nothing is it known as "Dismantling Fluid"! Given enough time (typically a daily application for a week) it should help loosen off the bolt. Once you have done so, cleaning up the surfaces is needed to get the distances right.

Just to give you an idea how sensitive the sensor can be, somebody on the forum fitted a new front sensor (on a Xantia) with the heat shield between the hub and the sensor. Only a couple of millimetres from where it should have been, but enough to throw the ABS system. Once they got it right (it wasn't me, honest!) the ABS settled down.

You can get Plus Gas from ECP (wait for Citronut!) for under £10 a can. It does really work, given enough time to soak in.

EDIT; By the way, I have a Xantia, so I don't know how much a sensor would be for your Pug. I got my good (well, they seem to be so far) front sensors off e-bay, at about £30 each.

Well I drilled out the metal sleeve of the new sensor which then just slid over the existing stuck bolt so there really shouldn't be any gap..
I've never heard of that stuff before, I'm guessing when I do get that stuff to remove the bolt (and glue) it'll be a case of keeping the car off the road during that week period, in case it really does fall apart - or am I exaggerating?
Thanks for your advice

[Hell Razor5543]

Not in my experience. Plus Gas is an aerosol spray (jet rather than spray), so you can aim it. Spray the offending area, let it soak in, and then head off to where you are going. Do this daily until you are ready (and so is the car!) to fix the problem. Given enough time it will soak into the rust and break it down. Forum experience would suggest a week should do. I have used it on crusty bleed nipples, and (provided you give it time to work) they have not argued when it has come time to remove them. Mind you, I have then replaced them with new ones (with copper grease on the threads).

This is what you are after;

http://www.ebay.co.uk/itm/Plus-Gas-Lubr ... 53fb45593b" onclick="window.open(this.href);return false;

[myglaren]

There are scads of multimeters on eBay. I bought one a few years back that has been perfect, paid fifteen quid for it but there are loads for a fiver that are more than adequate for your needs, like this one
Note the guff below, as it says, they are easily damaged if used incorrectly (seen that happen, guy on the next test bench to me turned one into smoke and shards )
At that price it is no great loss, although somewhat alarming.