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I ended up buying an ECU from a company online that is supposed to be programmed to my car already based on my VIN number. They say that it's "plug and play." It arrived yesterday and plugged it in. Car would crank, but not actually start.
I matched the ECU numbers from the old unit and the new unit. The number on my new unit is 89661-48070. My old unit was 89661-48071. Don't know if that makes any difference.
Other things to note:
The reason I got a new ECU in the first place is because I lost my only key to the car and then a locksmith scratched the new ECU where it was not usable. However, I do have the replacement keys already cut. They go in the ignition and can turn it, so don't know if there can be an issue there.
I did call my locksmith and he asked specifically about the security light on the left of the steering wheel. He asked what it was doing. It is blinking. He said it should be solid. He also told me that I could bring him the ECU to reflash.
I just wanted to see your all's thoughts about this. Is there any fix I can do? Did the company not program correctly? Or could there be another issue that I can fix easily. Thanks.
Also wanted to add, there is no "programming to vin" on these. To flash the immobilizer you write some simple hex code to an eeprom in the ecu that resets it to auto registration mode. When done correctly you add 3 keys (2 master and 1 valet) just by inserting them into the ignition switch.
The 1 at the end of your part number indicates that it is the updated version of the ecu you received.
Since you are not able to add keys then either the programming to reset the immobilizer is incorrect, or the keys have the wrong chip.
When your key is recognized by the ecu the security light will extinguish.
Is there a specific way to tell whether the keys have the correct chip? A locksmith was the one that cut the keys, but he was also the one that messed up the ECU.
Also, if the "programming to reset the immobilizer is incorrect," is that something that would be fixed by reflashing the ECU by the locksmith. I guess I could send the ECU back and get it fixed, but this will take a couple weeks at least.
Is there a specific way to tell whether the keys have the correct chip? A locksmith was the one that cut the keys, but he was also the one that messed up the ECU.
Also, if the "programming to reset the immobilizer is incorrect," is that something that would be fixed by reflashing the ECU by the locksmith. I guess I could send the ECU back and get it fixed, but this will take a couple weeks at least.
Since you are starting out clean, I would suggest have the reflasher wipe out all previous codes. Then send one or two keys to be registered as Master to the person who will reflash. You can even send the third and ask the refresher to register that as valet (make sure you mark them ... at purchase you get 2 master (black) and one valet (grey).
You can do some otf the work yourself as long as the ECU recognizes A MASTER key. Else do as I suggested above and pay extra for the reflasher's time.
I would suggest that you use private mail (PM) with Mouser and see how he can assist you.
Note: Please chose the flasher with care and make sure he stands by the work and not burn up your ECU.
The 1 at the end of your part number indicates that it is the updated version of the ecu you received.
Since you are not able to add keys then either the programming to reset the immobilizer is incorrect, or the keys have the wrong chip.
When your key is recognized by the ecu the security light will extinguish.
So I realized the ECU that was sent to me was the one that ended in 0. Whereas the one that was working originally ended in 1. Since the newer one is not the “updated” ECU, will that matter for it to start?
Didn’t know if this is something where you can go “forward,” but not “back.”
So I realized the ECU that was sent to me was the one that ended in 0. Whereas the one that was working originally ended in 1. Since the newer one is not the “updated” ECU, will that matter for it to start?
Didn’t know if this is something where you can go “forward,” but not “back.”
The ecu that you received would still allow the car to start if the programming is correct.
Is there a specific way to tell whether the keys have the correct chip? A locksmith was the one that cut the keys, but he was also the one that messed up the ECU.
Also, if the "programming to reset the immobilizer is incorrect," is that something that would be fixed by reflashing the ECU by the locksmith. I guess I could send the ECU back and get it fixed, but this will take a couple weeks at least.
A locksmith should be able to read the chip in the key. You need a 4C keytag.
If the programming is incorrect then a reflash should work.
I can send you a chip with the proper programming. If you are able to remove and replace a small surface mounted eeprom it is an easy swap.
This is the proper code to be written to the eeprom to put the RX300 ecu into auto registration mode.
A locksmith should be able to read the chip in the key. You need a 4C keytag.
If the programming is incorrect then a reflash should work.
I can send you a chip with the proper programming. If you are able to remove and replace a small surface mounted eeprom it is an easy swap.
This is the proper code to be written to the eeprom to put the RX300 ecu into auto registration mode.
Awesome job Mauser!
Do you have a good part# for the replacement EEPROM chip(preferrebly a Mouser pn#)?
I looked online and sites are saying the EEPROM is a 93C56 8 pin soic but they make a version A(8 bits) and a version B(16 bits) and have no way to confirm any of this is accurate and plus another thing this item is offered in several package styles.
If someone has an ECM open and wants to take a pic and get the numbers off it that would be fun.
We're looking for an 8 pin chip probably surface mount package style and hopefully be easy to find on the circuit board.
For anyone following along, please touch something metal to ground oneself before handling the ECU circuit board and never touch the processors unless you know what you're doing- plz do proper ESD handling.
I think my Xgecku programmer(ebay or amazon) should do it. I got mine in a kit with adapters.
Shown here is Xgecku(TI866+) programmer with 8 pin adapter installed.
Looks like the Xgecku supports both 8 bit and 16 bit for 93C56.
Mouser sells the 93C56(A/B)chips for $0.30ea so they are dirt cheap. I may buy a few on my next order and try to burn some just to see if the programmer will do it but need a good part# for the chip first.
Awesome job Mauser!
Do you have a good part# for the replacement EEPROM chip(preferrebly a Mouser pn#)?
I looked online and sites are saying the EEPROM is a 93C56 8 pin soic but they make a version A(8 bits) and a version B(16 bits) and have no way to confirm any of this is accurate and plus another thing this item is offered in several package styles.
If someone has an ECM open and wants to take a pic and get the numbers off it that would be fun.
We're looking for an 8 pin chip probably surface mount package style and hopefully be easy to find on the circuit board.
For anyone following along, please touch something metal to ground oneself before handling the ECU circuit board and never touch the processors unless you know what you're doing- plz do proper ESD handling.
I think my Xgecku programmer(ebay or amazon) should do it. I got mine in a kit with adapters.
Shown here is Xgecku(TI866+) programmer with 8 pin adapter installed.
Looks like the Xgecku supports both 8 bit and 16 bit for 93C56.
Mouser sells the 93C56(A/B)chips for $0.30ea so they are dirt cheap. I may buy a few on my next order and try to burn some just to see if the programmer will do it but need a good part# for the chip first.
Thank you Mauser!
Your pic is worth a thousand words. lol
Do you have a curernt avaiable replacement part# for this EEPROM and a recommended affordable programmer for DIY you like to share???
From Mauser's pic I can see a Fairchild logo so this is what I came up with so far, please anyone feel free to check my work, add info, comments, and experience, as much as you want.
*Note- original Fairchild EEPROM is "Microwire" programmable and appears to be obsolete but Microchip makes a replacement that is "Microwire compatible" serial programmable that I think can be a drop in replacement- someone plz correct me if I am wrong and recommend a better/alternative replacment if one exists.
Original EEPROM:
MFG: Fairchild
Part#: 93C56
Status: obsolete, may be found in surplus inventory
Data size/type: 2,048 bits arranged in 128x16
Communication: 16 bit, "Microwire", serial
Package: SOIC 8
Programmer: listed on device list for Xgecku
More info: see datasheet attached
Replacement EEPROM:
MFG: Microchip,
About part#'s: 4 choices so can choose whatever is in stock. T=tape and reel packaging(ignore).
Part#: 93C56B-E/SN or 93C56BT-E/SN, standard temp rating.
Part#: 93C56B-I/SN or 93C56BT-I/SN, industrial temp rating.
Status: active, current, readily available at mouser.com @ $0.30ea
Data size/type: 2,048 bits arranged in 128x16
Communication: 16 bit, "Microwire compatible", serial
Package: SOIC 8
More info: see datasheet attached Attached: Fairchild and Microchip's datasheet
Here is the dimensions for a replacement, plz compare to original and let me know if it is a match.
Also, happy to see the Xgecku programmer(ebay,amazon) supports the Fairchild as well as the Microchip version
Any tips, tricks, and info plz add. PS- very generous for Mauser to post up the "virginize data"
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Hi Mauser,
Not trying to put you on the spot so plz forgive me but have you considered becoming a Club Lexus vendor/sponsor and offer this as a paid service to members?
It seems like you've done qite a few and when I started looking into this last week and saw videos on youtube I didn't realize this affects so many models and some of the ECM's are becoming scarce to non-existent.
I realize this is way outside the scope for DIY except the "hard core" guys.
Requires delicate soldering experience for smd work and EEPROM programmers and tech experience and in my opinion that is value added.
Even with Youtube walkthrus this coud be a big challenge for someone who's never done it and they rather send it out for an ECM Reset than mess up their car.
Hi Mauser,
Not trying to put you on the spot so plz forgive me but have you considered becoming a Club Lexus vendor and offer this service to members?
It seems like you've done qite a few and when I started looking into this last week and saw videos on youtube I didn't realize this affects so many models.
I realize this is way outside the scope for DIY except the "hard core" guys.
Requires delicate soldering experience for smd work and EEPROM programmers and tech experience and in my opinion that is value added.
Even with Youtube walkthrus this coud be a big challenge for someone who's never done it and they rather send it out for an ECM Reset than mess up their car,
I do a lot of these on another forum. I don't do it for money, but for donations to charities that help US Military Vets or food banks local to the customer. In just under 2 years over $10,000 in donations have been made. It would cost too much for me to be a vendor here. I have already been scolded here for offering my services and not being a vendor.
07-02-21, 05:00 AM
NEW ECU Issues
