abs problem

[Finnon]

hello all,

i have a big problem with my supra,

the car failed its mot on the abs light staying on. i have pulled the codes for the abs and it seems to be throwing a code 24 and code 34. now i cant find reference to a code 24 in the toyota manual. does anyone have an idea what it could be?

for some reason the light flashes slowly at first for 3 flashes then does start to show codes.

has anyone on here had an experience of a fault like this before?

i know a code 34 is the speed sensor on the front, but it doesnt say which one. Is there a way to test them to find out which is the faulty one?

could it be a wiring fault?

oh my car is a uk 7m-ge btw

thanks

Paul

edit: just realised it was my first post, sorry for not introducing myself etc first.

edit 2: sorry if its in the wrong section aswell

 

[Big Wang Bandit]

http://www.cygnusx1.net/supra/techtip/engineerrorcodes.html
There ya be. Welcome to insanity!

 

[Finnon]

cheers for that mate, but thats for the ecu error codes,. as far as i can tell there is no code 24 for the abs. it jumps from code 23 to code 31 iirc. Ive used that site often and its a good resource non the less.

one thing i can think of is. i swapped the abs actuator over as there was an error code for the 3 position solenoid of the rear wheel. Its part of the actuator. the thing was it came from a turbo model and was slightly different to the original type. perhaps ill try refiting the electrics to it to see if that code 24 dissapears and the code for the 3 position solenoid reapears.

 

[Big Wang Bandit]

Lemme do some diggin for ya. 1 sec

 

[Finnon]

the code 34 im getting,

Open circuit in front speed sensor


* Speed sensor
* Sensor rotor
* Wire harness and connector of speed sensor

it doesnt say which side though, any ideas?

cheers

Paul

 

[Big Wang Bandit]

Okay this might be some good reading. This is the Repair manual for a 1990 or 1991? There must be a common ABS system. Do not take my word on that. :icon_conf

http://www.cygnusx1.net/supra/library/TSRM/br/BR_46.html

 

[Finnon]

cheers mate, ive read through the fault codes and there still seems to be no mention of a code 24.

perhaps im mixing an older type of computer with a newer type of abs actuator then and its not too happy about it hence the code 24.

ill use the info on there to check out the wiring though to make sure that is all fine.

cheers

 

[Finnon]

nice car btw, in the best colour aswell

 

[Big Wang Bandit]

^ Thanks!:icon_surp

Here is the link to the main page of the Repair manual. Its worth its weight in gold!

http://www.cygnusx1.net/supra/library/TSRM/index.html

 

[Finnon]

cheers mate,

ill look into what i said before about trying the old actuator to see if this misterious code dissapears.

il keep you guys posted as to what i find out.

does anyone know how to find out where an open circuit could be? as to the code 34 ive been getting?

 

[Nick M]

Most ABS codes that are speed sensor are where the wiring has been damaged/destroyed from something in the road. The sensor itself can fail, it just isnt likely.

 

[IHI-RHC7]

I would check the fenderwells inside the engine compartment and make sure the little white 2 conductor connectors are in good shape through the wheel well.

 

[Finnon]

the conections are all in good shape and ive tried all the tests in the online manual for the speed sensors, they all check out ie continuity etc

ill check the wiring after the connections tomorrow. but like i said the sensors seem to check out fine, unless the serated section of the hub has some debris in it perhaps

 

[Nick M]

You are looking for a sine wave and certain frequency when checking the speed sensor. A scope is needed.

 

[Finnon]

You are looking for a sine wave and certain frequency when checking the speed sensor. A scope is needed.

ahh right, i beleive a friend has an oscilloscope (sp) somewhere in his house. Ill have to wait though as he is away at sea just now.

 

[Finnon]

right ive printed off all the abs pages from the tsrm (that cygnusx1 site) also the wiring diagrams for the abs. ill keep you guys posted and hopefully we will learn what a code 24 is lol

 

[Finnon]

ive been checking the wiring with a multi meter today. using this list:

http://www.cygnusx1.net/supra/library/TSRM/br/BR_72.html

the folowing didnt do as it said they should:-

T - body ground. should show continuity (mine doesnt) ive checked the wire with the meter set to continuity and it beeps so that should be ok.

MR - R- show resistance 50 - 80 ohms (mine doesnt) the meter just stays on 1 (does that mean its showing infinite resistance?)

fr+ to fr- should show resistance, again mine doesnt the meter stays on 1

fl+ to fl- should show resistance, same again the meter just stays on 1

both of the last 2 checks for resistance should show a resistance between 0.8 and 1.3k ohms


any of you guys have any ideas as to where i should go from here?

cheers

Paul

 

[Finnon]

just checked the resistance values of the speed sensors on the car, the right hand side one is within spec but the left hand side shows no reading, ie it just stays on 1. luckily i have a spare left hand side which is within spec but its slightly deformed

edit: ive now rechecked the fr+ to fr- terminals and that checks out fine

 

[Finnon]

ive now plugged the abs actuator in and got the correct readings from all bar the front left hand speed sensor

 

[Nick M]

the right hand side one is within spec but the left hand side shows no reading, ie it just stays on 1

I don't know if you are familiar with working with electricity or not, so 1 is the meter's way of saying no continuity. The winding or wire to the plug is open electrically.