1989 JDM Celsior. (First Gen LS400)
About a month ago I started getting the TRC (TRaction Control) light coming on after about 15 - 30 minutes of driving.
This is the same light that normally comes on if I start to slip the wheels and the Traction Control is engaged in some way
Over the last month that 15-30 minutes has reduced down to 2-5 minutes, so its getting worse.
Engine check light is not coming on (the globe works as all the indicators light up when you turn ignition on).
When the TRC light come on I loose Traction Control, but until the TRC light comes on Traction Control works properly.
If I stop and restart the motor, TRC light stays off for another 2-5 minutes and TC works properly again..
I have not noticed what seems to trigger it, braking, Accelerating, turning, etc.
Most of the time when I have actually watched it come on I have been just sitting at cursing speed (80-90Km/h - 50-56mph) but I have noticed it come on when I was gently braking at about 15Km/h or 10mph
Apparently TC on these early models was a dog at high speeds, but I've found it to be very useful at low speeds.
Its pretty wet here in Australia at the moment and getting this heavy car quickly off the line at a hard left or right in the wet can be a challenge without TC.

Anyone had this sort of problem or have some idea of what to check to fix the problem?

Thanks.

 

There are variety of causes such as the speed sensor, throttle position sensor, air flow meter, weak TRC motor, voltage drop, TRC computer and many others.

I'd read the code first shorting E1 and Tc as is shown below. I don't have the code table for Gen 1 but I believe codes are mostly the same with Gen 2 which I have. When you read, you need to see and count how the TRC OFF lamp blinks. Inform me figures you read and I'll give you translated contents of the code. There are codes 24 to 56 and all those are explained in Japanese.

正常コード means normal code and 異常コード means abnormal code. 秒 means second. 例 means example.

 

It could also be the brake fluid level. When the fluid is low, the "trac" light comes on.

 

@ Yamae:
Thanks mate. I'll get the codes shortly.

 

@ deanshark
Thanks.
If anything its slightly overfull.
When I replaced the front rotors and pads about a year ago, opening up the calipers overfilled the brake fluid reservoir. Since then, the fluid level has come down a little (pads have worn a bit) but its still slightly on the overfull side.Fluid still looks good. No leaks anywhere. Infact my car currently has no fluid leaks anywhere. Top and Bottom of motor is as clean as a whistle. Same with gearbox and diff. For 30 years old, that's something I'm both impressed with and surprised about.