ABS diagnostic steps

[milty60]

My son bought his used Subaru with the ABS dash light constant on - seller is his friends brother - he said he pulled the fuse to stop ABS from kicking in. Fuse may of been out for up to a year until I put one in. ABS light is still constant on - ABS does not kick in when you hit the brake hard. I assume something - ABS pump - etc - is seized - etc. I've cleaned rust and crap from all wheel sensors. 

 

What DIY steps do you guys suggest to diagnose my son's ABS problem? 

 

Thanks, 

 

Milty

[Fairtax4me]

What year is the car? Older cars have a diagnostic plug that is used to make the ABS light blink codes. Diagrams, code definitions, and diagnostic procedures are all in the factory Service manual. Google around for a PDF download for your year and model and look at the ABS diagnostics section.

[golucky66]

9/10 times it's a wheel speed sensor that sets the light.

You need to get the codes. Abs can be very difficult to diy diag it.

[idosubaru]

mid 1990's ABS had faulty relays. 

 

If by "disabling" ABS the guy meant he was addressing an ABS issue - then it was probably this relay.  Subaru has an updated part for it. 

 

if he just didn't want ABS to operate then get the FSM or google the code procedure, it may depend on what year/vehicle which you haven't told us.

 

wheel sensors are the most common issue, the system isn't really that big or complicated, not many parts really. 

[Mike104]

Getting the codes is the first step, no point throwing parts at it until you know why the ABS light is on.  There is a procedure to install a jumper and count the ABS light flashes to get the code but that relates to the code.  Again it all depends on the year/model of your son's car.

[milty60]

My son's car is a 96 Legacy 

[Mike104]

Start here

 

http://www.ultimatesubaru.org/forum/topic/113645-how-to-read-abs-codes/

 

Download this for the TS flow for your code:

 

https://subaruport.ru/for1/for_01_chas_11.pdf

Edited August 16, 2017 by Mike104

[ricoc]

Thanks for the instructions to check the code without going to the dealer. But I have doubt about my interpretation. 

Can some one interpret my ABS light? I feel it's a 23 and 41 or 51. I am not sure about this. This is a 02 Legacy GT.

Here is the video I uploaded on youtube. 

https://youtu.be/1piYPVNTSwE