As some of you all know I got mid door level water in my 98 SC300 during Hurricane Harvey. Since then I bought a 99 SC300 and gutted/cleaned the 98. Since it will cost nothing to store the 98 and I am not paying registration or insurance on it there is no deadline to fix it. When I find an interior it will get done. But, before getting to that stage I want to get it running and check all systems to make sure things still work. I plan to document the repairs in this thread but it could be a long time so be patient.

The only part I changed so far is the SRS computer that sits under where the radio is located; did not want the bags blowing up as soon as a hot battery was installed. The engine ECU was completely submerged so I pulled it and let it sit for weeks in an air conditioned room. The chance of it working was next to nothing but I figured I would try it out. The keyless locks still work and the cluster will light up when I turn the key to start. I can hear the fuel pump running as well. That's about it.

From what I am telling you is the best move to buy a used 98 ECU (part number is one model year only and they did not make too many yikes) and have keys programmed to it? I found a shop that will take a used ECU and program a key for $250. With the cluster lighting does that mean the key is being recognized but that's it or the cluster will light no matter what if the key is cut to the barrel and turns?

 

I have nothing but time and patience, Dr. Frankenstein. Looking forward to this one!

 

Could you not send the original ECU to Tanin or your ECU rebuilder of choice and have them restore/fix it? May even be less expensive than going the re-key route...

 

I'm using ali sc3's guide for a jdm ecu and it requires no rekey.

I'm not sure why you need to reprogram the ecu for the keys your sc has a seperate door lock ecu and immobilizer they are not in the main ecu

 

A little bit off topic here, when you installed the SRS module, you have a 98 model with the newer box, how exactly did you do it? My computer has gone off and i've been putting off replacing it because I don't know what it'll do if I do replace it. Also the immobilizer computer is the one that deals with the key programming I think, so long as the ignition matches the key and the immobilizer sends the signal to the ECU, the car will fire up.

 

I called up the local Lexus shop that used to service my car and they advised me that the SRS computer is not programmed to the car. It simply detects signals from the cash sensors and fires the bags. My battery was dead and disconnected so I just undid 3 torx screws and swapped it. I am inclined to think SRS computers are not married to the bags because of so many steering wheel and airbag swaps people have done; no lights came on and their cars worked fine. So long as the part number is the same you should be good.

 

Where can that guide be found?

I would still debate doing it because of so many subtle differences they program into these cars just to make it harder to DIY and swap things. 1998 was a one year only ECU part number; that's total insanity when the engine is identical with DIS ignition from 98-00. This makes me miss the old days of the early 90s when it was all interchangeable and plug/play.

 

Never heard of Tanin but I will search for his info. But I am kind of hesitant to throw money at an ECU that was underwater for 36 hours and then sat under damp carpet for at least 3 weeks while I had more important house repairs to tend to. I'm pretty sure it is toast with corrosion on every point on the circuit boards.

Thanks for the reply.

 

Hi, Tanin Auto Electronix here. We are vendors on the site. We are really sorry about your situation with the flooded car and ordeal of going through Hurricane Harvey! Unfortunately, for ECUs, the ICs on the boards shouldn't be soaked in water. If it is turned on while damp, it will cause permanent damage.

We can however, locate a replacement ECU for you if you are interested. Give us a call at 262-456-4147 if that is something that we can assist you with.

 

That guide is for the older 92-97 ECU that has no immobilizer.

For programming the keys on a 98+ "t2d2" did a great of researching the information on how to program them in this thread:
https://www.clublexus.com/forums/per...ogramming.html

Theoretically, if you can locate a replacement ecu with 1 key, then you can swap the internals into your key and it should start right up.

*Edit* The dash lights will turn on regardless if the key is recognized or not. The way to know the key matches is if the red light above the key ring turns off.

 

I called Tanin and spoke to a gentleman who was more than extraordinarily professional. Unfortunately they are unable to help me with my 98 issue. No need to get into the details but if you have a 92-96 I would say call them for help and don't bother with the others out there.

 

Thanks for that info. I have a used ECU on the way and a locksmith lined up to program my old keys to it. There are many other factors that will determine if the car starts when I turn the key. However, this is the place to start since you can't expect electronics that have been submerged in dirty water for 36 hours to work as if it was no big deal.

 

Be sure to give all the harnesses a good cleaning before you connect the new ecu. Good luck with it.

 

UPDATE

Had to mail my existing keys and new ECU to a shop in the DC area. At around $200 they were very reasonable and outstanding at how fast they got it done. I get it back in the next 2-3 days so we shall see if the engine fires up. This is more exciting than finding and buying a car that is in good condition to begin with.

A few days ago I saw a 2000 SC400 with black interior for sale in my area and the thought of just killing the SC3 project, selling the car as is for parts, and buying the SC4 came to mind. After a few days to think about it I find there is much more satisfaction in solving a problem and fixing something. Oh, and my insurance company wrote down the value of the car to $1,000 after I got paid for a total loss and kept the car. They are telling me I can repair it and write the value back up once I have a title to legally operate it on public roads.

 

Well, the car is not firing so something else is wrong.

The keys seemed to be programmed to the ECU properly because the red light stops blinking when the key is put in. I tried a key for my 99 in the 98 and the red light keeps blinking with it. Anyway, with so many changes Toyota made to the ECU and electrical system of this car from year to year my next step is to buy a 98 specific service manual and check every circuit that has to do with the engine electrical.

Plan B at this point is a possible GTE conversion with new harness and ECU but I am not there yet. The body is too nice to let this one die.