ABS fault codes/ALDL test plug/Paper clip

[DiamondDriver]

I see the method of reading ECU fault codes by shorting out terminals A&B of the ALDL plug has already been posted but does anyone know how to read the ABS ECU fault codes by this method?

On topbuzz it says to short out terminals A&K of the ALDL plug   (See  www.topbuzz1.carenthusiasts.co.uk)   but on my 1994 2.0L Carlton estate the ALDL plug does not have a terminal at K.

I think I have cured my ABS problem by cleaning the rear sensor cogs (I tend to be overgenerous with the Waxoyl spray gun) However it could be usefull for any club member with an ABS problem and should narrow it down to a particular sensor, solenoid etc if read in conjuntion with the topbuzz ABS fault code chart.

The last time I had a Vauxhall garage read the ALDL plug was for the alarm system. He put his meter on the plug, destroyed part of my heated rear screen by scratching through a couple of the lower circuits on the glass, charged me about £60 and it made no differance at all!!!  Never again!

So anybody know?

[bstardchild]

I see the method of reading ECU fault codes by shorting out terminals A&B of the ALDL plug has already been posted but does anyone know how to read the ABS ECU fault codes by this method?

On topbuzz it says to short out terminals A&K of the ALDL plug   (See  www.topbuzz1.carenthusiasts.co.uk)   but on my 1994 2.0L Carlton estate the ALDL plug does not have a terminal at K.

I think I have cured my ABS problem by cleaning the rear sensor cogs (I tend to be overgenerous with the Waxoyl spray gun) However it could be usefull for any club member with an ABS problem and should narrow it down to a particular sensor, solenoid etc if read in conjuntion with the topbuzz ABS fault code chart.

The last time I had a Vauxhall garage read the ALDL plug was for the alarm system. He put his meter on the plug, destroyed part of my heated rear screen by scratching through a couple of the lower circuits on the glass, charged me about £60 and it made no differance at all!!!  Never again!

So anybody know?

Yes and no you can't fault code the ABS using the ADL link

Back to basics

- Check wheel sensors

- Swap replace one at a time the three relays in the system

Never known a ECU to go dead without water imersion

Modulator is fine as long as you don't blow all the fluid out of the system with an air line!!!

[Whippit]

Probably a silly question BC............how do you check the wheel sensors?

[bstardchild]

Probably a silly question BC............how do you check the wheel sensors?

Not silly at all

Jack up car on corner with wheel sensor you want to check

Unplug wheel sensor and plug an analogue multimeter (set to ohms - lowest scale) into the two terminals on the plug to the sensor

Turn wheel slowly and the meter should flick as each tooth and gap goes past

NOTE: Most digital multimeters are pretty crap for this application but I bought one for £1 in poundland a while back just cos I thought it's gotta be worth a quid and it was analogue - I only use it for wheel sensor checking!!!

[Whippit]

Cheers, got my old AVO 8 should work a treat 

[DiamondDriver]

Yes and no you can't fault code the ABS using the ADL link

Back to basics

- Check wheel sensors

- Swap replace one at a time the three relays in the system

Never known a ECU to go dead without water imersion

Modulator is fine as long as you don't blow all the fluid out of the system with an air line!!!

That's a shame.   Topbuzz did state  "Admittedly we don't know if all ABS ECU's used in the Vauxhall range have the fault code logging facility or not."
It's a hard way of finding the problem in comparison to reading the codes.
Thanks for your help and it looks as if I need a trip to the scrappy for some sensors and relays just in case I get a problem again.

[Dave the Builder]

an abs light don't stop your brakes from working.just means you have a fault,you just have normal brakes like in the good old days.sensors from scrapyards tend to have brittle wiring and its this that makes em fail.not expensive new if i remember correctly.allways worth having a pocket full of relays when you visit a scrappy though.
that said ABS has saved me in some very near misses before.tiss a good tool to have.
now someone shout at me and tell me I'm talking b***ocks....

[mrchaz]

I found it easier to check the sensors with a meter at the ABS ECU (under the passenger front seat). You can check them all without having to jack up the car that way.

Pins 6 & 4.....front left
Pins 11 & 21..front right
Pins 8 & 9.....rear left
Pins 24 & 26..rear right

Put the meter on Ohms, unplug the ECU and check the values on the plug. Can't remember what the values should be but all 4 should be about the same, if ones different the thats your dodgy one.

[DiamondDriver]

an abs light don't stop your brakes from working.just means you have a fault,you just have normal brakes like in the good old days.sensors from scrapyards tend to have brittle wiring and its this that makes em fail.not expensive new if i remember correctly.allways worth having a pocket full of relays when you visit a scrappy though.
that said ABS has saved me in some very near misses before.tiss a good tool to have.
now someone shout at me and tell me I'm talking b***ocks....

Dave, yes & b***ocks!  The car may have still stopped but braking hard especially at speed with the ABS banging away was like suddenly driving over a pile of bricks. Bloody unnerving especially when you're never really 100% certain it's just an ABS system fault.

Take your point about brittle wiring on the sensors though.

[ian]

.allways worth having a pocket full of relays when you visit a scrappy though.

and all fuses+a selection of screws and bolts,
my pockets dont half get heavy at times

[HMK]

I've done a bit of work on Carlton ABS systems & I seem to think I've probably posted on this subject before - & so have others........Do a search!!

You'll be lucky to get any sensors out in one piece at the scrap yard

They are expensive from Vx - £80 odd seems to ring a bell when I last enquired 

Don't be fooled if you find one that gives a different reading to the others - I've found that there can be as much as 500 ohms difference between sensors & they will still work fine

Expect a reading of between 1,000 - 1,500 ohms (1k - 1.5k). They usually fail 'open circuit'

I find it's the rear ones on the diff that fail.........DON'T try to remove the sensor from the bracket while it's still bolted to the diff - I did on the first one I had to do, & the bracket broke straight off What you do is to go to a scrap yard & un-bolt the bracket complete with the sensor & replace as a unit - £5 should be the going rate .........If you can find a Carlton in a scrap yard these days........In this area, I'm likely to buy any scrap ones that I get to hear about, if they're not too far away & easy to get home, & break them to keep my fleet on the road for the next few years

[carlton_mad]

omega ones are the same iinm