Programming transponder key and ECU Issues...

[504InfinDog]

Hey whats going on NICOs. I have an issue with my 99 Q45 that has me quite confused; I’ll explain the situation. My keys were stolen from me nearly two months ago which left me with no way to operate my car, I had no spare. Sucks, I know. Upon having my keys stolen, I went forward and called a locksmith to make a transponder key for my car. For whatever reason the technician explained to my mother, he was not able to make a transponder key, but cut a door key for the car so that I could get in and out, roll the windows up etc. I then had popalock to come and service the issue; however, they could not get a reading from the car to program the transponder key. So finally I brought my car to the local Infiniti dealership. There they had informed me that my car’s ECU was not responding to any of the computers they had connected to the car and suggested that I replace the ECU. The technician gave me a price for the specific ECU for my car which was a little over $1400. The technician then notified me that once I replaced the ECU, that it may not be guaranteed that will resolve the issue to have a key programmed for the car. This is all puzzling to me because the car was running just fine before my keys were stolen. A mechanic that is a close friend to my father told me that my car thinks it has been stolen and has shut down. All in all, my question for anyone here is: Is it possible for me to insert an ECU that does not match the exact model number as the one in my car, but from the same year and model and still have my car operate?(the technician informed me that the ECU I need is 2371M-3H001/RE) I have priced several other ECUs for the car which are substantially cheaper than $1400. Has anyone ever dealt with a situation similar to this? Looking forward to some feedback/responses.

[Q451990]

to NICO!

Gotta love that kind of diagnosis... "why don't you throw $1400 at the problem, but if it doesn't fix it you're SOL"

Check out your car's factory service manual, available at www.infinitiservicemanual.com

It goes in to a lot of detail about the NATS system, and what the security indicator lamp should be doing at different times. All of this starts at page EL-458. It does seem curious that everything worked fine with your old keys. There is a "lock mode" that comes in to play if someone attempts to start the car with an unregistered key more than 5 times, but the dealership technician should have seen that with Consult during the diagnosis.

I think I would get a second opinion... where are you located? Maybe someone can recommend a lock smith with a Consult, or a good senior tech. that has experience going back to when that car was newer.

[504InfinDog]

Thanks for the welcome and link to the service manual. Yes, it's very strange the car isn't operating now...I am located in New Orleans. In the meantime I'll attempt swap my ecu with one from another vehicle and hope to get a reading.