Robnh

iTrader: (1)

Hi - I have a 1998, LS400, and after some troubleshooting and repairs, and checking OBDII codes, I have determined I need to swap the ECU.

I've obtained a good, low mileage ECU - part number 89662-50010. I now need to swap.

I have read a lot of posts on this, and they cover many years, as there are some differences both in ECU's, key transponder requirements, key challenges, etc...

What I am looking for is a little advice as to the EXACT steps I need to take to swap out my old ECU/ECM and replace it with this newer good one.

I am using the word ECU and ECM interchangeably here, as different posts I've read use both terms. They are one and the same.

Requirements vary from year to year, but I need to get a quick write up from someone who owns a 1998, and has addressed this problem before.

Among my questions are the following:

1. Is there a step by step process for the swap (not the physical aspect of location/unplugging and connecting the new one - as that is easy), but the sequence of events you need to take to activate the new ECU? If so, can you provide detail as to exact steps you took?
I don't want this to turn into an ongoing nightmare, as I rely heavilyon my car for daily use and really need to avoid any unforeseen circumstances.

2. Will my key require re-programming to be compatible with new ECU/ECM?

I guess that's it for now... I very much thank you in advance for any guidance you can provide.

Thanks,

Rob

Mauser

Just swapping out the ecu wont work. The new ecu will not recognize your keys. To use the new ecu you can either have it flashed or you can swap the immobilizer chip from your old ecu.

Robnh

iTrader: (1)

Thanks, could you provide any info on where I might find the immobilizer chip on the new ECM? What does it look like? where on the PCB does it it? Any guidance to offer?

Mauser

Pull the board out of the ecu. The chip you are looking for is a 93c56 eeprom labeled IC900

Mauser

Here is a quick video I did swapping an eeprom in an ecu from an LX470.

Robnh

iTrader: (1)

Mauser - that was an awesome video.... extrEmely helpful.

Question: are you sure the chip is the same 'IC900' in the 98 LS400?

Did you ever do this on a 98 LS400?

Rob

Mauser

I havent ever done a ls400, but have done several lx470s, land cruisers, rx300s and an es300. If it is a Toyota or Lexus the immobilizer eeprom is IC900.

timmy0tool

iTrader: (7)

great video!

to the OP, what made you determine it's the ECU?
ECU problems plague earlier models (90-94 primarily and a handful of 95-97) and hearing a later year car (98-00) have this problem is rare.

Robnh

iTrader: (1)

Robnh

iTrader: (1)