Lexs400

1990 LS400 w/trac.
I wanted to know where the ABS ecu is located. because after checking all the sensors for a code 35, the lights of trac off and abs is still not going away. So i plan on swapping the ABS ECU to see what that does.

I tried to reset codes using the methods described. It says to jump the TC and Te1 and to take the jumper pin off.
the only place I found the jumper pin was on the far right side of the hood under a plastic cover. Is that the correct jumper pin used to reset the codes ?
thanks in advance. !

PureDrifter

iTrader: (10)

www.lexls.com has a tut i believe.

Lexs400

i checked but i didnt see any where the abs ecu location was mentioned...

AzHotLS

iTrader: (1)

It looks like it's in the center of the dash behind and climate control unit from what I can tell.

t o y o d i y.com/parts/p_U_1991_LEXUS_LS400_UCF10L-AEPGKA_8414.html

LiCelsior

iTrader: (32)

alldata + mitchells owns.

Lexs400

thanks for that input. Would I access it from inside the car or from the hood ? I have to change it to see if the codes causing are the ABS ECU itself or not. thanks again !

LiCelsior

iTrader: (32)

it should be under the glovebox. the cover under the glovebox is very easy to remove, just held in by clips, so u can pull it and it'll come off.

Lexs400

thanks for that.
would you happen to have the wiring diagram from the speed sensor to the ECU by any chance. I want to check the wires for connectivity as well while I'm at it. thanks again ! much appreciated.

LiCelsior

iTrader: (32)

PureDrifter

iTrader: (10)

ahh, my mistake, lexls has a Cruise Control ECU tutorial.

Lexs400

Could it be that the ABS ECU is bad but only code 35 which is an open circuit code is coming up ? Would a bad ECU not throw a specific code that would point to a bad ECU unit ?
From the codes, bad ECU would keep the light always on.... ?
any ideas. thanks in advance.
p.s. would i have to access the abs ecu from inside the car ?

nthach

Check the ABS sensors and harnesses at each wheel. The ABS light is on - that means the ECU is getting power but is detecting a fault.

To access the ABS ECU, drop the passenger knee bolster. It'll be mounted on a bracket and the engine ECU is right by it.

Lexs400

Thanks, yea well I've checked the sensors. The code is 35 meaning it's front left or rear right sensor that has an open circuit. I've checked the sensors even replaced them as I bought new ones but the code is still there.

What happened was that I gave it for suspension work and the mechanic broke the rear sensor. without telling me the guy then soldered the sensor back but that obviously wasn't done correctly. Now even with a new sensor in place the code doesnt go away. I'm thinking that during the course of soldering / tampering with the sensor too much voltage probably went to the ECU. ( my guess) and has tampered with the ECU itself. Otherwise,why would putting in a new sensor both in the rear and front not resolve the issue...

PureDrifter

iTrader: (10)

when he broke it, he may have broke the connector or the wiring AFTER it, so replacing just the sensor wouldnt do much.

nthach

Go to a junkyard and get the wiring connector and piggytail. You have 2 options to splice it back on -
a. You can solder+heat shrink the connection, this results in a more reliable connection
or
b. Use a butt splice, crimp it and heat shrink it.