Programming ECU ECM
Thread Starter
Driver
Joined: Feb 2017
Posts: 79
Likes: 4
From: MD
Programming ECU ECM
I searched but could not find an answer so I post the question here. I have a 97 LS400 that needs to replace an ECU, do I need to program the ECU (used from EBAY) before starting the engine or just swap and let it learn by itself hopefull after awhile everything becomes normal? If the answer is yes, how do I program it? I saw someone programmed it online for Toyota ECU (basically, short between pin 4 and 13 of the OBD port and claimed that it also worked for LS400 as well but wanted to ask here before doing it.
Lead Lap
Joined: Nov 2019
Posts: 3,693
Likes: 1,102
From: Michigan
Hello,
I think your LS400 should already have an immobilizer (you can tell it by the key you have), which means that you will not be able to just plug the new ECU in and hope that it will work, you will need to program your key into it. With that, there are several ways to do it - let the dealership program it, or try to follow procedure described here.
Hope this helps and best of luck!
I think your LS400 should already have an immobilizer (you can tell it by the key you have), which means that you will not be able to just plug the new ECU in and hope that it will work, you will need to program your key into it. With that, there are several ways to do it - let the dealership program it, or try to follow procedure described here.
Hope this helps and best of luck!
Thread Starter
Driver
Joined: Feb 2017
Posts: 79
Likes: 4
From: MD
That video is impressive. Thank you Arsenii for providing the link. Mine does not have chip in the key so I think I do not have to do it (all the wiring, hacking, and all good stuffs). My car starts up fine with the Ebay-ECU (with correct part number). I am just concerned if I miss anything because some sellers on Ebay specifically ask for VIN number to program the ECU before shipping.
Lead Lap
Joined: Nov 2019
Posts: 3,693
Likes: 1,102
From: Michigan
That video is impressive. Thank you Arsenii for providing the link. Mine does not have chip in the key so I think I do not have to do it (all the wiring, hacking, and all good stuffs). My car starts up fine with the Ebay-ECU (with correct part number). I am just concerned if I miss anything because some sellers on Ebay specifically ask for VIN number to program the ECU before shipping.
I am not exactly sure why sellers ask for VIN number, I think every seller has his own reason for that. Maybe they can even get the ECU to the shop and really program your key in it..
CL Community Team
Joined: Aug 2011
Posts: 4,172
Likes: 1,006
From: Japan
A 97 LS400 has an immobilizer system but it has a separate unit other than the ECU. You can use another ECU without any problem if the ECU is a good one.
The ECU learns your driving habits as you drive the car and you don't need to program anything. All you need is just to drive your 97 some more. Sometimes it takes more than 100 miles to complete the learning depending on conditions.
The ECU learns your driving habits as you drive the car and you don't need to program anything. All you need is just to drive your 97 some more. Sometimes it takes more than 100 miles to complete the learning depending on conditions.
Thread Starter
Driver
Joined: Feb 2017
Posts: 79
Likes: 4
From: MD
Thank you Yamae and Arsenii ! That keep my head straight.
I drove it around this afternoon for an hour and it ran fine without any fault codes. All the sensors seem to report like they are working. The old ECU gave me code P0773 (there was something else too) and I could not start the car at all. I sent to a repair shop (found on Ebay) but they could not repair it, said the main processor was dead. I don't care about fixing the old one anymore as long this one is working.
I drove it around this afternoon for an hour and it ran fine without any fault codes. All the sensors seem to report like they are working. The old ECU gave me code P0773 (there was something else too) and I could not start the car at all. I sent to a repair shop (found on Ebay) but they could not repair it, said the main processor was dead. I don't care about fixing the old one anymore as long this one is working.
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