Check Engine Light

[sternern]

I have a 1990 LS400 with almost 200,000 miles. The check engine light will not shut off. Even after the Dealer said it was fine. I reset the battery and did a few other things. Anyone have any ideas on why it wont turn off?

thanks...

[VMF]

you can try to locate your ECM and put it into test mode, write down the codes it gives you and later on just try to find info about those codes online, after putting your ECM into test mode it will reset it, and your check engine light should go off, also those error codes should give you some info about what is going on in your car. for cars younger then 95 there is a special scanner for those things but for cars before 95 you have to do this manually. i'm not sure how to do it on lexus, i did it on my brothers legend and my friends maxima and it worked. try to look for more info on how to do it for your LS.

Good luck

[cnacne]

Under your hood there should be a black cover usually located on the drivers side that says DIAGNOSTIC. You want to short TE1 and E1 with a paper clip or short wire run. When these two are shorted get in the car and turn the ignition to ON, do not start. The engine light will blink the first number in the error code, pause then blink the second number. Count these, post them here and I'm sure someone can help you out.

Joe