Hello Lexus pilots,

On my 1992 SC400, the Trac light stays on after a cold start in the morning. This doesn't happen all the time, just once in a while. Then, after I stop and shut off the engine, this doesn't occur again for the rest of the day, and usually not for several days. My traction control system functions normally. What's going on here, anyone?

By the way, I too have experienced those "electronic gremlins" that I've heard about. Weird stuff like the old cell phone turning itself on and refusing to stay off, the Trac, ABS and Trac Off lights going on all at the same time, and the engine hesitating a bit, while I'm cruising down the road. This went on for a few days until I noticed that the screw that attaches a smaller cable to the positive cable on the battery was loose. I tightened it and have not seen those gremlins since, so I don't think this is related.

 

run a self diagnosis test.. search the threads.. i think it mite be related to some o2 sensor

 

Like persian said, it could be a defective oxygen sensor, or for my case, a bad charcoal canister, which happened last month on my '01 ES. The TRAC light would stay on constantly though, not like yours where it goes off and on at irregular rates. You should bring the SC to the dealership and have them run a check on your car to find out the source of the problem; it's not easy to find out on your own.

 

If the trac light is the ONLY light that stays on, then probably trac related. I.e. sub-tps, actuator, or accumulator. Get the codes pulled, I dought if it's O2 related. Especially if it's cold start only.

DD