Trac light stays on - Big or little problem?

[Speedo]

A few questions re Trac dash light that stays on. Vehicle is LS400 1991.

Articles on this site point to bad speed sensors as the most likely cause of this. Is this a problem worth ignoring, that causes little or no real harm, or does it reduce gas mileage, or otherwise definitely needs to be fixed? Thats question #1.

Q #2:
If best that it be fixed, whats the best way to proceed? Keep in mind that I'll have to take this to some shop for the actual work being done.

 

[Lextreme II]

This is a very common problem. 8/10 owners have this problem. There are many reasons why the light comes one, but all are very costly to repair. If the light is not affacting the engine performance and other issue. I would just ignore it. I had the same problem before but i hit the dashboard few times and the light is off now. Not sure why. I might broken it or its just a faulty light.

I have the most innovative and high tech way of fixing this problem and the cost is less than one penny. Would you be interested? You can also u an inch of black electrical tape and tape over the light. The light in on the top of the instrument cluster. Its the reflexion of the light on top that allow you to see. Before u tape. Turn on your engine and let it runs until the light comes one. Once its on, move your and around the top of the cluster and your hand will block the light. Eyeball it and tape the black electrical tape over it. Light disappeaar and no change in performance and function.

This is not the best, but the cheapest.

 

[Speedo]

Big or little problem?

I appreciate the black tape idea... have already used it on another irritating faulty light in the dash.

What I don't know is if the speed sensors being bad or the light being on most of the time constitutes a nuisance or a real and serious problem that should be fixed.

I take it you dont' think it is serious, and I thank you for your input.

Any contrary opinions out there?

 

[Lextreme II]

My idea sound cheesy, but its the one most mechanic encourage. The fixing of the light can cost thousands and after one to two thousands or so, it might not be fix. For me its more of an eyesore then anything else. I would also like to find out what other think too.

 

[Speedo]

Speed sensor - ABS system connection

I'd like to get other's opinions on this if anyone feels knowledgeable...

Further reflection on the TRAC LIGHT coming on as a result of bad speed sensors in the wheels: if speed sensors are bad, and not reporting the correct wheel speeds, won't the ABS system work incorrectly from the bad data, possibly causing mishandling during a heavy (ABS inducing) braking situation?

Does anybody know?

 

[deathblow]

i had the same problem with my sc400. they said it was the speed sensor but i found out after i replaced it it was not. It was the o2 sensors that cause the trac light to come on. i Would tell you to change them firlst before you jump to the speed sensor.

 

[Speedo]

I appreciate the info.

Where are the o2 sensors located, how many are there, and how expensive a fix is this?

 

[deathblow]

Well my sc400 had 4 o2 sensorrs 2 by the cat and anther 2 a couple alittle bit more down. I think i paid like $30 -$50 each you would have to go to a store near u to see how much they will charge. BUT you can install it your self it only took me like hour and a half to do every thing.

 

[GSMnow]

I currently don't have my manuals here, but I would suspect you can us a jumper or something and read the error code. That should tell you what the TRAC ECU "thinks" has failed. On board diagnostics may not be perfect, but they sure can help show you where to look. When I do get my LS400 motor up and running in my Celica, I know I will be tracing down a few "Check Engine" light codes to make it all happy. Wheel speed sensors are a common failure since they are in a hazardous location, but I would also expect an ABS error light to come on if one has failed. I would look at things like the secondary throttle motor and TPS as these are TRAC only items. Most of the other signals used by TRAC also tell the engine ECU and ABS systems something like vehice speed, throttle input, brake status, etc. If the TRAC OBD gives a code for a failed TRAC ECU or ABS pump assembly, then tape over the light.

Gary M.

 

[gdaelemans]

Good thread - been dealing with the stupid light on and off for a few months. I usually manually overide Traction control and keep driving... figuring that it's an expensive fix.