ABS Self Test

[Spannergal]

I know that any vehicle fitted with ABS will perform a self-test when the vehicle is started.

What I want to know is what it actually does during the self-test and what conditions would stop the test?

[dazzag]

it checks to see if there are any faults such as short or open circuits in the abs components like the sensors or the auctuators. the test stops after a pre determined time set by the factory

[Spannergal]

yeah, i knew what it was testing for - but I'm needing to know how it does does the test. figured since there are a few mechanics on here (and google seems to have stuff all) that I'd ask here

[matt dunn]

yeah, i knew what it was testing for - but I'm needing to know how it does does the test. figured since there are a few mechanics on here (and google seems to have stuff all) that I'd ask here

It measures the voltage to the ECU through the circuits to make sure the inputs and outputs are all connected and have the correct resistances.

[Spannergal]

thanks matt. thats what i needed to know

[GTCRSHR]

yeah, i knew what it was testing for - but I'm needing to know how it does does the test. figured since there are a few mechanics on here (and google seems to have stuff all) that I'd ask here

It measures the voltage to the ECU through the circuits to make sure the inputs and outputs are all connected and have the correct resistances.

and what are the voltages suppose to be do you know ?


And what should be checked/replaced/cleaned when the ABS light stays on permanently on a AE101 fxgt

should i reset the computer 1st ?

cheers for any help

[fivebob]

and what are the voltages suppose to be do you know ?


And what should be checked/replaced/cleaned when the ABS light stays on permanently on a AE101 fxgt

should i reset the computer 1st ?

I don't know what the voltages should be but I have been working on a document that tells you how to check the ABS fault codes. It's not complete but there should be enough information to allow you to check and reset the codes see http://www.users.on.net/~fivebob/ABSCodes.htm for details

[aesc]

Having your ABS light stay on isnt a good sign im afraid. have you had any suspension work done on it since its started lighting up? They might have damaged one (or more) of the sensors. And the are $&#$% hard to find 2nd hand for Super Strut as well as I have found out previously, and very expensive new

[GTCRSHR]

yeah have just had the suspention done ....

and yes the light is permanently on ... i dont want to just take the bulb out or anything

i want it working properly... i had a scout around the web and have narrowed it down to a few things ... wheel sensors, abs sensors, and the need to have the computer reset /.cleared


i just want to k now what to look for.... and which way to tackle them if its easier to have new ones put in then so be it ... but if there hard to come by ...


what sort of price would i be looking at would mr revehead have these?


cheers fivebob interesting read (similar albeit easier to read than that russian one)

... can any damage be done if this is done wrong ... ?

cheers !

[aesc]

In that case theres a high possibility that they have damaged the internal wiring of one of the wheel sensors, visibly you wont be able to tell which one it is Apparently if they havent been removed from the hub in a long time then the can get stuck, which requires force to get them out then thats when breakages occur.

Im hearing ya, because if your ABS isnt working then your insurance could be voided if you have an accident

I think when I needed mine a second hand one cost about $120, but they are very rare. And theres 2 different typres for the front atleast as I found out, pre 5/92 the sensor part is 17mm, post 5/92 they are 16mm. I got a pre 5/92 sensor and it wouldnt fit into my hub So i just got the hole reamed a little larger, they still work fine. The only diff between the two is the diameter I think new they were around $350 ex japan

I would be going back to the suspension place and telling them to fix it since it was obviously them who have done it

[matt dunn]

and what are the voltages suppose to be do you know ?

No, and you dont need tp know as there is no way of testing or trying to fool it.

I think new they were around $350 ex japan

I would be going back to the suspension place and telling them to fix it since it was obviously them who have done it

I agree, take it back and get them to fix it as they will have stretched the wires. they will never admit it though as they seldom do when they dont understand.

The nissan we were doing abs on at work today are over $700 for a sensor!!

99% of the problems you get with ABS is a sensor,
or something that someone has shagged with.
(unless it's amn early falcon)

All the jap stuff is too reliable for other problems.

You can diagnose with a basic multi meter but you need to know what your looking for.

Matt

[GTCRSHR]

cheers for that guys

at least i know what im on about and what to look for now


does any one have a picture of the wheel sensor i can give to show them what it looks like or anything else that could have been damaged

if there just not put back in properly would that cause them to stop working also as i have never seen one i dont know how they sit or are connected in

so a pic would be great (i dont have the car on me for a while)

Cheers once again

[aesc]

I did have a pic of a sensor on the car but have since deleted it. Ill be home tomorrow night I can take one and email it to you then if you still need it

Practically impossible for them not to be mounted properly. In the front they bolt onto the hub and they have a small cylindrical shaped head on them with a rounded end which goes into small hole in the hub which reads the teeth of the CV I think. The wiring for them runs across the front control arm and then bolts into the wall of the wheel arch

[GTCRSHR]

hey yeah that would be great if you could send a picture over

chriselse@gmail.com

cheers !!!