Traction Control Appears To Not Work At All

[dpellet]

Hi There,

Any assistance with this issue would be greatly appreciated.

Just purchased a US model 91 ls400, 116 original miles and is in very good condition. Wish I new about the forum prior to purchase but oh well.... Everything appears to work perfect with the exception of the trac control, it does not light up at all and no response to pushing the trac button either, is there a way to tell if the system is even functional. Checked for codes and got nothing at all other than a 41 that was related to the steering that I just had overhauled. (shop did good work but man was it expensive, good lesson for me. They have done something to the spiral cable and will be looking at it tomorrow as my horn, cc no longer are functioning and the airbag light is on and I am unable to clear it but they are responsible and will take care of it.

Any assistance with checking my trac system would be appreciated as I don't want to pay shop diagnostics if I don't have to.

[leximus]

Simple question, have you checked the fuse for the TRAC? Maybe the previous owner had something done to the TRAC system?

[dpellet]

Simple question, have you checked the fuse for the TRAC? Maybe the previous owner had something done to the TRAC system?

Thanks for responding.

Checked the fuse first, would have been nice to see it blown but not the case. Any thoughts?

[daffy]

Hi dpellet,

When you press the switch in, does the light on the dash light up? That would mean, it is shut off. Press the switch again and the light should go out, indicating that it is working. If on ice or snow or maybe gravel(ugh), you can best tell, if it is working, as another light comes on when accelerating, and you can hear the back brakes doing their job, stopping the spinning wheel. Daffy

[dpellet]

Hi Daffy,

No lights at all, thanks for the information though as it's good to know what is supposed to happen. Could it be that the light itself is out??? But then would at least except it to be working but I'll give it a go on a little gravel tomorrow and see what happens.

Other thoughts?

[Rx330driver]

another thought may be the previous owner wanted mroe sporty driving my disabling it forever so that he didnt have to keep pushing button. i doubt it, but some people do that. dont know how they would do it either...dont own the car and im not usually on this forum

[wwest]

The only functionality the early Trac systems can or will provide is a warning of slippery roadbed conditions of which the driver may otherwise be unaware. In my 92 LS I quickly learned to always disable it, religiously turn it off each time I started the LS. On the other hand it may have failed ('91, miles??) and some "wise" dealer removed the Trac diagnostic icon bulb so you wouldn't know, notice.

[chilkoot]

^The 'trac on my 90 saved me several times, especially in snow. Even if you didn't have a trac off light, was your trac lite blinking? That'll be your clue that its doing its job, but before it kicked in I definitely felt my car slipping and it gave me back control.

To the OP, it could be that a wire leading to or the trac off button itself is broken, and the rest of the system is fine; thus no lights. I can't imagine a failure so bad that traction control wouldn't work and the trac off light still would not come on, at the very least you'd see the trac light. My traction control still works and my trac light is on the majority of the time, i'm surprised you don't have any lights just due to age.

[fencera]

Something obvious, but I would double check to make sure your car does in fact have traction control. It is possible that the previous owner changed out a broken ashtray with one that had the button despite the fact the car doesn't have trac. I have seen it before.

1. Make sure the throttle cable cover says "trac" on it (under the hood).

2. There should be two sensors, not one, on the side of the throttle body that are easily visible.

Probably isn't the problem, but just in case...

[wwest]

Something obvious, but I would double check to make sure your car does in fact have traction control. It is possible that the previous owner changed out a broken ashtray with one that had the button despite the fact the car doesn't have trac. I have seen it before.

1. Make sure the throttle cable cover says "trac" on it (under the hood).

2. There should be two sensors, not one, on the side of the throttle body that are easily visible.

Probably isn't the problem, but just in case...

In '92 heated seats and trac were a combined option.

[fencera]

ie: If the seat heaters work, you have trac.

Attached are diagnostic and mechanical pages from the manual that may help determine the problem. I have no idea how mechanically inclined you are, some of the procedures are rather complicated.

Good luck.

br_165.pdf

br_168.pdf

br_163.pdf

br_155.pdf

br_76.pdf

[dpellet]

ie: If the seat heaters work, you have trac.

Attached are diagnostic and mechanical pages from the manual that may help determine the problem. I have no idea how mechanically inclined you are, some of the procedures are rather complicated.

Good luck.

Thanks all for the info, I definately do have the opiton as the trac unit is under the hood and also have the heated seats. I'm leaning toward the bulb being removed due to possible problems, is it as easy as taking the trim piece off the front cluster to check em?

[dpellet]

Ok, the trac bulb is missing, likely to be issues with the system but cannot diagnos it until I can find a replacement bulb. I've looked hig and low and checked with local dealer who advises they are not stocking and cannot locate. Anyone know where I can purchase them?

[dpellet]

Here's an update:

A few bulbs burnt out in cluster, all fixed and working now.

The trac/ABS light issue wound up being a disconnected ground on the trac actuator unit, once found very easy fix.

Latest issue after clearing codes is a trac code 19 - pressure leak somewhere and I think the culprit is right on top of the trac actuator unit, the line that shares with the ABS actuator is a little wet and looks like it was installed off angle so hopefully the threads are not trashed!!