P38A ABS Fault + Suspension lights "always on"

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R

richl

Member
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28
Location
Bath, UK
Here we go again!

Further to my thread about the BECM (thanks for all the replies!) we "sorted" that and got a new battery, but that went flat last week after not been used for a few days.... So we relented and bought the YWY500170 (Turns out it had already been upgraded to the "interim" one). I've just fitted it, but... I'm not sure if these new problems are related to that, the battery going flat, just coincidence, or...?

- ABS Fault on the display, and the three abs/brake/tc lights stay on. This has happened before, but "reset" when the ignition was turned off. The nanocom reports "01-07 Brake Switch Failure". Is this likely to be one of the pedal switches (the brake lights work fine, might it be the cruise one - is it a simple continuity test?) - or something to do with the ABS unit? Browsing "the internet" suggests it could be either...

- The Air suspension works fine when running (goes up/down/etc) but when the ignition is off, all 4 height lights and the lockout button light are permanently on.

Also, when I was just reversing back to park after a "test run", first the HVAC fans stopped, then the dash almost appeared to "reset" itself (lights off, then on with temp warning light, then "OK") - it did that a couple of times, then seemed "fine". It didn't do it when I was going forwards!

Are these issues related? Suggestions welcome.... (if they are cheap, preferably!)
icon_smile.gif


Cheers
Rich
 
Look at Nanocom live data, brake switch has two contacts, when one is made other is open. They should swap senses as the brake is pushed. If they don't you will get that fault. May just need resetting may need a new switch. Look at RAVE for how to set switch.
 
wammers said:
Look at Nanocom live data, brake switch has two contacts, when one is made other is open. They should swap senses as the brake is pushed. If they don't you will get that fault. May just need resetting may need a new switch. Look at RAVE for how to set switch.
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Not sure about the other things. Has the BECM got wet? Or you may like to take a look at the delay relay.
 
Last edited:
I think the fault was "just" a corroded connector - all the faults have gone, but the dash is still rebooting... i'll have another clean!

Out of interest though, which are the two fields in the nanocom live data? I can see "footbrake" which switches when I put my foot on the brake, and "cruise switch" which is the one on the dash. I couldn't spot anything else brake related...

Rich
 
richl said:
I think the fault was "just" a corroded connector - all the faults have gone, but the dash is still rebooting... i'll have another clean!

Out of interest though, which are the two fields in the nanocom live data? I can see "footbrake" which switches when I put my foot on the brake, and "cruise switch" which is the one on the dash. I couldn't spot anything else brake related...

Rich
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Look in WABCO D on your car. Go to INPUTS screen 5. You should see "Brake switch 1" and "Brake switch 2". One should be open one should be closed. They should swap senses as the pedal is pushed and change back when it is released.
 
wammers said:
Look in WABCO D on your car. Go to INPUTS screen 5. You should see "Brake switch 1" and "Brake switch 2". One should be open one should be closed. They should swap senses as the pedal is pushed and change back when it is released.
Click to expand...

Thanks! I hadn't spotted that...

I've just been out and checked (ignition on, engine off). They both start out closed, then as I slowly push the brake pedal switch one goes open as the lights come on, then a bit further switch 2 goes open...

So they do both change - just not in the same way as yours! I'm guessing that's "OK" though...?

Rich
 
richl said:
Thanks! I hadn't spotted that...

I've just been out and checked (ignition on, engine off). They both start out closed, then as I slowly push the brake pedal switch one goes open as the lights come on, then a bit further switch 2 goes open...

So they do both change - just not in the same way as yours! I'm guessing that's "OK" though...?

Rich
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No that is the fault, they should never be open or closed at the same time one should always be open when the other is closed. The closed one should open and the open one should make when pedal is pushed then revert to normal when pedal is released. If they are both open or both made at any time it will throw a fault. Either switch needs setting or it needs changing and setting. See instructions in RAVE for setting or replacing brake switch.
 
oh right - that is odd then. It's not throwing any fault codes at the moment though! I might just change it anyway to be on the safe side... I'll look into changing it, and see what happens when I clean the connector properly!

Rich
 
richl said:
oh right - that is odd then. It's not throwing any fault codes at the moment though! I might just change it anyway to be on the safe side... I'll look into changing it, and see what happens when I clean the connector properly!

Rich
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There's not a lot in it to go wrong! Switch just twists and unclips behind metal thing hanging down behind brake pedal. 3 quid for shipart or 11 for the real deal and I think 3 of that was postage.
 
richl said:
oh right - that is odd then. It's not throwing any fault codes at the moment though! I might just change it anyway to be on the safe side... I'll look into changing it, and see what happens when I clean the connector properly!

Rich
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When mine was duff it only ever faulted to ABS fault never put the TC lamp on as i recall. One switch is for brake lamps the other one is cruise control related. It disengages cruise when brakes are applied. Petrols have a separate vac release switch also.
 
Touch wood, it seems that all the ABS/Suspension/Dash faults were cured by cleaning the connector in the door pillar, and (hopefully) curing the leak round the scuttle air intakes.

I've spent today replacing coils to hopefully cure a misfire!

It's all fun and games...

Rich
 
richl said:
Touch wood, it seems that all the ABS/Suspension/Dash faults were cured by cleaning the connector in the door pillar, and (hopefully) curing the leak round the scuttle air intakes.

I've spent today replacing coils to hopefully cure a misfire!

It's all fun and games...

Rich
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You nearly had me going then, COILS (as in suspension) oh no. :D:D
 
ha... no! :)

The coil packs behind the engine where you need to dismantle half the engine, and then have to have tiny hands with joints in odd places to get to the bolts!

Fingers crossed. Seems to have had the odd misfire reported since, but not the continuous stream like before :/
 
as an "aside"... When removing the connector from one of the coils, I accidentally "fired" the metal lock wire thing *Somewhere*. Despite searching, I can't find it.... I've "borrowed" one from the idle valve (I think - the one right on the top of the engine!) connector - but... does anyone know if/where/etc I can get a replacement?

It's in the attached photo - any idea what they are "called"? Bit annoying! Suggestions welcome though...

Rich
 

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richl said:
as an "aside"... When removing the connector from one of the coils, I accidentally "fired" the metal lock wire thing *Somewhere*. Despite searching, I can't find it.... I've "borrowed" one from the idle valve (I think - the one right on the top of the engine!) connector - but... does anyone know if/where/etc I can get a replacement?

It's in the attached photo - any idea what they are "called"? Bit annoying! Suggestions welcome though...

Rich
Click to expand...

Make one from an old metal coat-hanger?
 
ha... tempting :) I'll just stick a cable tie round the connector on the top - I used the "proper" bit for the coil, as I definitely don't want that dropping off... :/
 
i think you push the metal bit to disengage ,dont remove it and if its the same size as other connectors ,there will be one unused some were on the car.There on all pugs citroens ect ...:)
 
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