wonderb

Have a bad ECU on my 96 LS400. opened it up and it looks like bad caps (two have given up their interior liquids onto the board). don't have the expertise to solder competently or the time to wait for the specialized caps to come in so I've snap ordered a replacement ECU.

I matched the numbers on the back plate of the ECU perfectly to the one I ordered, but there is some concern in my mind about the possibility of an immobilizer or other security system throwing a hissyfit and ruining my life.


Now, I know the car doesn't have a chipped key and doesn't need the factory key fob with the key to start, because the only key I have right now is a "dumb" key with no such chip.


Can I safely swap out the ECU if the numbers match?

Lzam

Save yourself the headache and order the correct capacitors 16.99 on ebay I just did mine. Work like a charm and you can clean the board with 91percent alcohol. If not you may waste more time and money.

sha4000

iTrader: (1)

You can swap out if they are the same part number but you don't know how long that used one will last or if it's damaged already. Just get the capacitors and have yours fixed so you don't have to think about it again.

https://www.clublexus.com/forums/ls4...capacitor.html

wonderb

Thanks for the answer and suggestions guys. Didn't have the time to find someone to do the soldering job for me (have zero experience nor a sodering gun or...well a car to go get one lol).

I will order the capacitors for this replacement unit and find someone who can put them in for me. does suck to have to spend $100 I wouldn't need to if I had more time to just do the job on the original unit...but such is life I guess.

black_LS

1996 was the first year for the immobilizer system. You cannot simply swap out the ECU on 1996-2000 cars and expect it to work unless you swap the keys as well. There is, of course, the reprogramming option. I'm not sure about the key you're currently using.

wonderb

I don't think my car has an immobilizer if it's tied to the key, because this is definitely a "dumb" key with no fob, and the ignition box was already replaced so I doubt it matches to that.

Just to make sure I'm going to call the local lexus dealership, hopefully they'll know something concrete since I've been getting mixed answers from google on this.

black_LS

If you've already ordered the ECU, swap it out, and if the it only runs for 2-3 seconds before dying, then it's an immobilizer issue. It more than likely will, but you never know.

black_LS

1996/1997 cars had an ECU immobilizer unit (part number 89780-50020).

Just showing proof that they exist.

wonderb

I might have gotten lucky then, my number is 89661 50303

anyway we'll find out tomorrow lol.

black_LS

The part number I provided was for the immobilizer unit (separate computer) just to show you that it exists, not the ECU.

wonderb

aaah I see, where's it located in the car? not that it matters at this point I'm screwed or I'm lucky, but may as well find out now rather than tomorrow.

wonderb

Update: hooked it up and she fired right up! ...and stayed on lol.



For anyone that has a similar problem to mine and is confused by the differing information out there:

looking online the part number
http://www.lexuspartsnow.com/Page_Pr...er=89780-50020
says 08/1996-07/1997 for the applicable date compatibility.

my car was made in 03/96, think that's why there's so much conflicting information for my car! Cars made before 08/96 shouldn't have an immobiliser, cars after should. If you're wondering how to check, look at the metal on the opposite side of the driver's side door on the inside after you open it. there's a bunch 'o information including tire pressure and manufacture date.

At least, it's a good theory for now. Hope this helps someone in the future.

RA40

iTrader: (6)

A follow-up for others with a similar production is to have the dealer run the VIN# to verify.

python

iTrader: (4)

+1!!!!!!!!!!

wonderb

=\ I agree with this wholeheartedly as a starting method, however in my case I rang about 8 dealerships in florida and left messages for the service adviser.

4 of them gave me calls back, of those 3 said they weren't sure and 1 said it wouldn't work (the day the part arrived so I just tried it anyway)

was somewhat surprised they couldn't just look it up (did provide VIN) but I guess that's what I get with an 18 year old car.