eknine9

iTrader: (8)

So my ABS light has been on for awhile an after replacing the brake lines, checking for vacuum leaks, and fully bleeding the brake system the brakes are still a bit mushy. So I jumped the diagnostic ports today (e1 and Tc) to see what code I'd get from the ABS system.

However I've had an air-bag light on in my dash since the Previous owner, who stated it came on when he had the viper alarm installed and they removed the gauge cluster. And when I jumped the ports I got the airbag code (code 41), which I expected, however the ABS light did not blink at all. It just stayed on, which I'm unsure if that means anything since all of the dash lights stay on anyways when the key is in ACC. However, this page says that if the ABS light stays on there is a malfunction in the ECU.

http://www.lexls.com/tutorials/intro/codereading.html

So has anyone else tested their ABS system? If so what did you get, and does the always on mean there's an ECU malfunction, or does it mean something else? Would an air-bag light stop the ABS light from blinking? Any help or input is appreciated, as I would hate to have a mechanic or the dealership fix this if I can do it myself.

I'm not really looking for any help with the air-bag light, I just included it in case it was relevant to the ABS light, I'm fully aware of how to reset the air-bag light, it just isn't a priority for me right now.

t2d2

iTrader: (8)

I've had the Airbag light on throughout my ownership and it didn't result in any ABS codes when I checked on that awhile back. My scenario was a bit loopy, though, as I had found an odd little fella down in the engine valley when replacing fuel injectors, and later realized it's the ABS jumper pin that's supposed to be in the diagnostic box. Someone must have dropped it down there years ago and left the ABS disabled. So, I put it back in and checked for codes, and everything appeared okay.

Did you remove that jumper when checking for ABS codes? It's necessary to do so, as I recall. The SC300 could be different, but I think those instructions applied to both. It's a very vague and confusing aspect.

eknine9

iTrader: (8)

Jumper pin in the diagnostic box?
By the diagnostic box you are referring to the obd1 diagnostic port, or are you referring to somewhere else? I'm not familiar with the term.

t2d2

iTrader: (8)

Yeah, the main diagnostic box in the engine bay. I imagine your '92 is the same setup as my '94 in that respect, both being OBDI. Check out this post:

https://www.clublexus.com/forums/per...ml#post6124292

That's the one that made me do a double take, having recovered that little 2-pin jumper (bottom right) from down in the engine valley. It's for pins WA and WB, as covered in the factory service manual on BR-52, pg 1021 in my PDF version.

eknine9

iTrader: (8)

Ok well I just checked my diagnostic port and I'm not missing the jumper, it's in the correct place on my car. I'm kind of at a loss as far as what to check. I guess I'll look at some of the wheel speed sensors and the connections to the ECU, but I have no idea what could be causing this brake feel and the non-code ABS light.

t2d2

iTrader: (8)

That's good you've got the jumper, but you supposedly need to remove it for checking the ABS codes. That might explain your uncertain results.

http://www.justanswer.com/lexus/3q85...97-causes.html

It took me quite a bit of searching to find any info on that jumper and what role it serves.

eknine9

iTrader: (8)

Hmmm okay, I'll remove it tomorrow and see if I can pull the code with it out then. I'll report back if it works or not for others.

eknine9

iTrader: (8)

You were right t2, thanks for the heads up.

ABS codes can only be checked when the jumper is removed from the diagnostics box..
After removing the jumper I'm getting code 35, which is a short in the vehicle speed sensor in either the front left, or rear right wheel. Makes this quite a bit easier for me. Hopefully this problem will have an easy/cheap solution, but I've got the car in the air now and I'm going through the sensors.

t2d2

iTrader: (8)

Glad that worked! I can only assume that very few people have had to deale with pulling ABS codes, or simply assumed there were none to pull for this very reason, because there's extremely little info out there about that jumper. Now we can share the info with certainty whenever the issue arises, so more people are likely to find the answer in searches.

oldManTan

i pulled my ABS ECU out completely eff that stuff lol all my sensors were messed up when previous owner changed bearings.