I know this has been covered over and over again, but can't find any relevant topics.

Where are the relays, how to check the sensors are working, etc... any answers much appreciated.

CheeRS
Greg

 

 

on a saph,?

the abs ecu is above the engime ecu behind the glove box

 

Yes, on a saph dave,

I just can't remember which relays are involved in abs, how to test wheel sensors, etc...

It's all been posted here before, but I can't find it

 

whats your doing (or rather not doing..?)

 

The ABS tends to kick off while you are slowing doan and almost stationary, say like stopping at a traffic lights. Not breaking hard, just normal. ABS kicks in, pedal becomes really hard, you let go and then it breaks normally.... you get used to it!!

 

Ok, coast to a stop at traffic lights for example, and as soon as the car's speed drops to say below 5mph, the pedal kicks back and hardens as the abs kicks in. You have to keep your foot on it for the car to stop.

No light in the dashboard to indicate a fault, however, I know it works as it sometimes comes on

Sounds like the ABS "thinks" a wheel is locking up when it's going real slow. Just wanted to check the obvious before taking it to a specialist.

I have checked/cleaned the wiring in the engine bay (to the abs pump unit) so far, and no change.

 

this happened to me a twice frog .and it only happened after i had removed and installed the front drivers side wheel sensor,my fix was to remove the sensor and give it a good clean,by wipeing across the the face,some sensors have a rubber transparent cover over the face so be careful,i also cleaned in between the grouves on the cv joint ,you can see them if you look down into the sensor hole,it cured my problem and it hasnt happened since

 

Check its on the right side

 

Thank you all, looks like mrsFrog and I posted at the same time

Anything else to check ? How about making this post a reference for ABS problems

 

i would say definitely make sure the grooves on the driveshaft are clean.if there is a build up of dirt it can produce an incorrect reading(old bmws also suffer from this)

 

the problem that you have mr & mrs frog is an imbalance of speed readings between front and rear. i have had this on both all 3 of my sierra's and have cured it either by cleaning sensors and mounting face, or replacement (front only).

there are only 2 relays for the abs, green for the ecu, and purple for the pump. they are located behind the glovebox, clipped to a square metal bracket.

 

Hi,
Have a look here for my home grown method of testing the sensors, etc. http://bbs.rsownersclub.co.uk/showthread.php?t=71707

HTH
Iain

 

My 2WD Saph does EXACTLY the same thing. But like you said you kind of get used to it so i havnt really bothered with it. But it sure does piss you off when when the pedal becomes rock solid, it just messes with your judgement of distance to stopping.