I read in the past posts on this but, everyone is giving different answers.

1)Disconnect battery for 20 mins
Problem:Keyless entry may have to be reprogrammed, time erases and radio settings erased. Don't know if the seat settings are erased also.

2)Take out ECU A , ECU B fuse, and Ign fuse for 20 mins.

3)Take out EFI fuse for 3mins.

4)Don't reset. Adaptive ECU will do it for you automatically.

So, which one of the four or are these solutions wrong in resetting the ECU.

 

#1 will do the job, but you will loose the seat settings and the radio station settings.

#3 will also to the job, but without a need to reset anything else.

#4 I don't necessarily trust the ECU to adjust properly automatically.

Chris K.
95 SC400

 

thi might be a dumb question but, what will reseting the ecu do?
thanks

 

It will "refresh" ECU settings. After the ECU learns your driving style it tries to set everything to save gas. This could mean that when you want to drive more aggressively for some reason the ECU won't perform to its limits (better acceleration vs. less gas).
Also, some people believe that after installing performance parts, for example a new intake or mufflers, this helps ECU to optimize settings.

Hopefully this helps,

Chris K.
95 SC400

 

does the ecu in the sc300 do the same thing?

and how often do you guys reset the ecu?

 

This is something I've wondered abiout myself. I'd really like to hurt whoever thought up the adaptive ECU, it's the only thing I don't like about my car. I wonder if anyone knows how to kill adaptive mode, or permanently set it on max?

 

black SC.....I have a 92 SC300 and reset the ECU not to long ago. If u have a 92-94 (or 95 mabye) SC4/3, disconnect the battery for 20 min. and then reconnect it. Yes u will lose all programmed settings (seat memory, radio, etc.) but if u cant remember them, u can write them down before u disconnect the battery. However, if u have an SC later than a 95 (or 96), then i would not recommend doing this because it might mess up ur key and then u will have to go to ur Lexus dealership and buy a whole new key which is at least in the high 200's if not higher (i have fogotten what the guy told me it would be exactly). I do not know to much about the other ways, but they all sound right to me. If u disconnect the battery, then wait about 5 min. after u reconnect it and go out and drive it like a sports car (do not go out during rush hour, etc.) drive it hard for at least 10-15 min. and u should notice a difference in shifting, etc. Hope this helps.

 

I agree with MADMAX the adaptive ecu SUCKS. I wounder if disconnecting any of the sensors and installing some type of device to send a false signal would do anything. DOES ANYONE KNOW HOW TO CANCEL OUT THE ADAPTIVE ECU, OR JUMP IT FOR PERFORMANCE.

 

Yes, I hear you. The '96 and later have the OBD 2 ecu so, I can understand that.

See, the thing is I did the procedure involiving pulling out the ECU A and ECU B, and Ign fuses in driver-side kick panel. When I installed intake and spark plugs. I noticed that the car was improved but decided to pull out the fuses a day after I installed intake and spark plugs. I drove really aggressively for half a day. Now, I notice a burning smell sometimes when I am driving under 40 mph. I am wondering if, I am running too rich or is my catalytic converter burning.

That is why I want to redo the procedure again but, correctly this time.

 

This works for both the VVT-i and early models right?

 

"Holy pull a thread from 4 years ago Batman "

But definitely props for searching!!

Peace,
Jonny

 

Remove an excellent ECU that helps gaurd against silly owners doing silly mods, and allows more timing advance to take best use of better gas etc? It is a great bit of the car, and unless you run all-out 100% of the time on 100+ octance fuel, it is best left alone. The basic learning and closed loop feedback of the ECU is not costing you any HP.

 

Exactly, leave it alone...or get another car if you want to race all the damn time, period. Don't buy a luxury cruiser and think you can easily make it into a race car. De-engineering isn't always easy...or smart.