Hey Guys,
I just picked up a 97' LS from a mechanic shop behind my work. They indicated that the vehicle is not communicating with the ecu. My question is, how can I determine if the ecu is the original one that came with the vehicle from Lexus and not a replacement? Is there any way to tell?
Thanks so much!

 

Yamae has a listing of ECU par#'s for the respective models. Recapped ones done by a shop will likely have a sticker on them. Most likely it is the original that will need to be re capped.

 

My worry is, the ecu currently in it, has already been sent out and been replaced with a different 97' ecu not native to the vehicle. If I am not mistaken, 97' was the first year that the immobilizer option was utilized. If that is the case, how can I start the car?

 

sounds simple to me, maybe I am dumb.. but use Yamae's part number for the 97, yank yours out and put his in.. it runs or it dont..
it should be priced to where you can take a chance...

 

I believe if you call a Lexus dealership and talk to the people in parts and service they can look up your car by VIN and tell you if you have the correct model, but I don't know how that applies to the immobilizer; that may be serial specific. As already pointed out, rebuilt models will likely have shop stickers. Additionally, look for paint pen on the casing; this indicates a possibly salvaged part.

However, I will also say I just replaced all the capacitors in my 97 and all I have left is to test a diagnostic tool to see if I got function back. My advice is to pull the ECU and visually inspect it.

Stupid question, but is it not starting and that's why it was behind a mechanic's shop?

 

My suggestion would be to pull it and call the dealer for the part# to compare. As well contact the shop that sold the car and get as much history that they have so you can piece a plan of action together for this.

 

For the record, 1997's have a separate ECU immobilizer that connects to the ECU. So changing the ECU wont effect your key programming