acmay

93 LS400
On the second start of the day and beyond, the "TRAC" lite illuminates (without the Check Engine lite). What should I check and how do I identify and reset the ECU?
Thank you.
ACM.

tenpointed

I don't remember which fuse controls the ECU in your car, but you can check the owners manual or the fuse box covers to identify the fuse. Just pull it, leave it out a couple minutes, then put back in (hmmm, kinda sexy ). I'm not sure if that will help you with the TRAC light though. I know that there is a TRAC fuse in your car, so maybe it needs replacing.

Lextreme

The method above might not work. Easiest way is to unplug the battery for few hours. Eventhough the power is out, the TRAC still comes on after few minutes of driving. TRAC light comes on could due to the followings:

1. Traction Control System
2. One or more speed sensors (located by the tires/brake system)

Try this. run you car in a low traffic street. While the car is running (moving), turn off your engine for about 1 second and turn on again. Do it while you are in D gear. You should notice the TRAC should be off. The turn off and on procedure is done while the car is moving.