powerbob

The Knock sensor needed to be replaced (both of them). The CEL causes the Trac Off light to illuminate. The Trac OFF light had nothing to do with the transmission, wheel sensors etc. The Autozone and other code reader read the code to be a knock sensor problem. The knock sensor replacement was expensive but it did correct the problem. By the way the car would not alway go into OD when the Trac Off light was illuminated (some protect default setting by the car computer). Hope this helps the next guy, bob

Replace both knock sensors since the labor will be 1/2 of the repair cost. The sensor will cost about $185 each from Lexus and about $165 from discount parts houses. both sensor are located under the manifold therefore replace both and do not try to guess which knock sensor it bad...good preventative maintenance. Lexus shop labor was about $550 plus parts (knock sensors 2, gaskets and assorted shop charges) for a about $1,000 repair bill just before Christmas. The good news is that the check engine light and the trac off light are now off. By the way the Trac Off light comes on whenever the check engine light comes on. Bottom line: replace the knock sensors and your CEL and trac light will be off, you will be able to stay in OD even after the wheels slip. By the way turn off the engine to reset the computer to be able to go into OD until you get the repair work completed. Your vibration may be another thing that is not related to the knock sensor failure. Get the work done at Toyota to be sure you are getting all the code read correctly and factory replacement parts will be used to replaced your failed parts. my 2 cent, bob

The knock sensor diagnostic probably means the engine is sometimes running too lean. That can be due to a failing fuel pump, a plugged up fuel filter, or even an engine intake air filter. It would not be unusual for OD to be disabled with a CEL and the Trac is a default condition when there is a CEL. Fix the CEL problem and Trac will be okay. wwest, Therefore there is no known cause for the CEL (check engine light) and Trac Off. Both come on when the check engine light comes on. I have noticed the check engine light and trac off come on going straight down the freeway. Then it may or may not be illuminated when I re-start the car. The check engine andt trac off seem to turn on for no apparent reason. Can Lexus service diagognose and read the code to determine the CEL problem? Other code readers could not read any codes related to a check engine light. The OD will work with this check engine light and trac off illuminated until the wheels slip, then the transmission will not go into OD. The car needs to be turned off to re-set the computer to go back into OD at highway speeds. thanks, bob

Are you sure you are getting the transmission into overdrive? The high RPMs may be due to not getting into overdrive. I get 24-25 MPG when all is working properly. I am having problems with the overdirve and have seen the MPG drop to 21 - 22. But I have stopped and turned off the car to re-set the computer to allow the transmission to go into overdrive so prevent additional fuel consumption. I am still fighting the problem and have been looing to this forum to find a cause for the check engine and trac off indicator coming on my 2000 es300. bob

2000 ES300 I have had a the check engine light and trac off light come on simultaneously. The lights will occationally go out, but then return later. No codes other than P0330 Knock sensor register on the Autozone code reader and my mechanic's Snap-on code reader. I have also noticed that the car will not go into overdrive if the wheels happen to slip with these dash warning lights lit. I have to turn off the engine to reset the computer to get the car and transmission to go into overdrive properly. The transmission will go out of overdrive after the wheels slip and the transmission drops out of overdrive. Is this a known problem on the 2000 ES 300and what is the solution? Thanks, bob

Did the Hi Flow cat converter correct the check engine and trac off light problem? Did you notice if the car would not shift into Overdrive consistently? I have noticed that the transmission will not shift from 4 to 5 consistently with the check engine light and trac light on. My mechanic was seeing a code 61 but could not decipher the code 61 meaning. bob