Margate330

Hi members,

Just for fun I ordered a replacement ECM for my 2004 Lexus RX330 with 150k miles so I will always have a spare but also to see if the car runs better/different with a replacement ECM.

Here is the replacement I got on ebay matching the part number.



First, I opened it up to inspect and found a bad capacitor locted at C200.



So I replaced the capacitor with a new 1uf @ 50V and visually inspected the board-
Here is a pic under my soldering microscope of the repair located at C200.



Now it's ready to go in the car but I don't know if I can set it up thru Techstream so it will run and work with my existing keys or is
there another different & easy proven way?

Edit: My car currently runs great I only want to swap so I will have an extra ECM ready to go if I need it and to see if car runs with more pep/etc.

>> Has anyone done a swap or an have experience to share?
>> What needs to be done to make it work with my existing keys?

PS- I found videos and stuff elsewhere but no real walk thru that I know will work for sure on this year/model and not looking to take
chances on my only vehicle so if someone has done this please let us know and I will try it and share my results with everyone.

Nad1370

My understanding is when an engine ECM is replaced, you have to register the ECU COMMUNICATION ID between the ECM and the transponder key ECU.
But this is on a brand new un-married ECM.
I dont know if it'll work on a used engine ECM from another vehicle. <-- could work.

Either way, its pretty simple to marry the Transponder ECU to the engine ECM.

Register the ECU communication ID.
--- After the transponder key ECU and/or the ECM is replaced, turn the ignition switch ON (the engine is not running).
--- Short the TC and CG terminals of the DLC3 and leave it as is for 30 minutes.
--- Check that the engine starts.

FWIW:
Only way i know for a vehicle to run with more "pep" than stock is by reflashing the software to run leaner with more timing with no knocking, retarding, etc...without tripping any codes.
Or a piggyback controller. Need a wideband to monitor AF ratio when tunning.
I remember the old SAFC days with my Honda/forcefed rice burners.
Butt dynos dont count so if you cant generate more than 20whp on your pursuit w/ more "pep", id lighten up the load instead.
Maybe chuck the driveshaft and rear end and make it a FWD. lol <-- i shouldnt laugh since i might go this route this summer.
Well.. the driveshaft part of it.

Good luck.

Margate330

Success!!!
Awesome Job thank You!
ECM swap works perfect as detailed by nad1370 and was very easy.

Steps I took in detail to make this as easy as possible:
0) Move the seats back all the way to give yourself extra room or it may not be fun squeezing up in there. haha- added 03-09-2022
1) Start up car and charge up battery- I didn't do this and ran my voltage down into 11V's but I was lucky it didn't quit half way thru- draws a lot of power it seems.
2) Unhooked battery and pulled the radio fuse to save juice and waited a few mins.
3) Carefully replaced ECM.
4) With no key in ignition I carefully jumped the two pins with a paperclip as shown in previous post by nad1370.
4.5) Hooked up battery.
5) Turned key to on position but Did Not Start the engine- turned off all lights and unneeded accessories to lower power drain.
6) Waited 30 mins- for this step it doesn't matter if someone opens or closes the doors because I did it several times- but didn't mess with anything else.
6.5) Hint: lots of lights in dash lit up like christmas tree and blinking all over- don't freak out, lol -this is normal and means it is "pairing to the Immobilizer".
7) After 30 mins I turned the ignition key to off and removed the key.
8) Next I removed the jumper.
9) Started car!

Here is the location of ECM- glove box removal required.


There was no Check Engine Light after the swap.


Next I ran a health check with Toyota Techstream and scanned for codes and found a code for the Immobilizer(but no Check Engine Light)- which I cleared and no probs.


After clearing it I ran the car until normal operating temp and printed live data.


I drove the car around a few blocks and all is well.

Observations of the live data comparison:
1) Normally my car ran approx 15 dregrees ignition timing and now it's running 18 degrees at idle.
2) My calculated load usually averaged around 14-15 but it is now reading approx 20 at idle.
3) Techstream reads the last vin stored from the ECM- which is not my VIN- but I didn't have to change it unless I want to because car still runs.

Tomorrow I will drive it more and see if the engine responds any different with the ECM swap.
>> Sorry about the bad pics my phone doesn't like taking pics of my laptop screen.

PS- Anyone swap an ECM or seen ECM issues on our model or have more tips to to add plz share.

Margate330

UPDATE AFTER ECM SWAP...

Butt dyno and scanner says everything is the same after ECM relearned after some miles including ignition timing, etc.

When I test drove a 2009 RX350 last year it had a more snappy throttle response vs my car so I guess I was just dreaming a fresher ECM might make any difference at all in how it runs.

>> Maybe I'll do a valve lash adjustment next since I do have a ticking lifter on bank 1- anyone done this??? Any difference???

I wish our cars has more throttle response and Pep!

Nad1370

1/3MZ uses a bucket type with shims.
Pop a valve cover off and use a feeler gauge to measure valve lash on each valve.
Although i doubt this will give you a better throttle response even if its way out of specs.
Simple to do though if you know your math .lol

Our vehicles are simply under powered and overweight.
Although im getting a little better get up and go from a stop switching to my winter wheels (lighter) with a smaller diameter tire.
I dont dog it whatsoever since im preserving my tranny which i believe is a weak point on the 1st gens.

Margate330

02-12-2020

Interesting update- still running on my swapped ECM and everything is good.
My wife drives the car about once a month to get groceries and stuff and I thought I would have to do this pin jump procedure again to program her key to the ECM too.

I completely forgot about it until she got back from the store and then realized her keys already worked too!

It seems this procedure programs all keys to the ECM with this one time procedure somehow.
>> Is the key info stored outside the ECM somewhere?

Nad1370

Keys never communicate with the Engine ECM on this system.
Transponder ECU does.
Keys ---> Transponder ECU ---> Engine ECM
Your keys has always been paired with the Transponder ECU.
It was your replacement ECM that needed pairing to the Transponder ECU