After months of trying to sync up with the Nissan tech to get the ECU/ECM reprogrammed we finally got together this weekend. This is for the O2 P0140 TSB and updated MAF that I recently replaced. So he plugged in the Consult II and started the process. It started reprogramming then it gave an error that the car battery was low and could not proceed. We then decided to move the car inside the service and hook up the battery charger and do it that way. Well, the car would not start then, it turned over but would start. We pushed it in, tried a few more times to start and nothing. The tech figured that the reprogramming started, erased the current program and since the battery was low did not download the latest program so that is why it cannot start. He told me to go home and that on Monday (today) he will try to get service the cover it under warranty somehow (I am just outside it at 82K ).

Today came, I called this morning and he told me that he found a broken wire at the ECU that he fixed it and the car can start now. He also told me that he could not reprogram the ECU saying that he thinks that something inside it is messed up and as a result I need a new one. They are more than happy to sell me one for $800! So I drove off with my old ECU and the car runs (no SES for now).

Before this I had SES on even after I replaced the O2 and reset the ECU/ECM for P0140 and some driveability problems that I unsuccessfully tried to solve with new updated TCM, MAF, coils...

I am asking you for some advice:
1) should I go and buy a new ECU/ECM or can I get a used one?
2) are used 2K ECU/ECMs programmable (I am fed spec) so I could program for O2 and MAF?
3) I am also considering buying a new car

Any advice is appreciated

 

See if the CEL's come back.
Check out www.car-part.com for an ECU
Make sure there no other broken ECU wires.

 

Thanks, I looked it up already over the weekend , found some in the area for $150-200. Will give it 300 miles to cycle and if it comes back will perhaps try going that route first... Dave B also quoted me $600 for it...

 

I have an extra ecu that a friend gave to me, I'm not sure if it is fed spec or not, so I will check. If interested let me know.

 

Sure, please check, thanks

BTW, my SES came back on for same P0140 this afternoon...

 

Thanks... I would need the VIN for the car this ECU came from. Apparently, my car is a 2000.5 edition and the ECU would need to be the same from the later half of the year and any from the earlier would not work. From the options I would need: auto, traction (TCS), federal.

ECU internal number (can be pulled out by Consult II) to be 23710-2Y964 or higher number than 964. Latest is 23710-2Y967...

 

It would be impossible for me to get the vin. Is there another way to check? The only numbers on the outside are...

A56-M29 Z02 9415 and a barcode 04520983-WA56M29Z02WW

 

Darn, I went through this with wreckers and dealers. I called a few wreckers and all they could give me was the s/n and dealers could not tell me if they would fit or not. I nailed it down to one wrecker whose ECU might fit based on the VIN it came from. It will be a $200 gamble. If it does not work I will need to buy a new one (Merry X-mas to me )...

 

I'v been thinking of hooking it up to my car just to test it, but I'm concerned it may damage something.

 

Thanks, appreciate that, but for your cars safety, don't do it... Used one is only $200...

I have just ordered a new O2 sensor from oxygensensors.com and will replace it to see if the SES goes off first, and if it still persists, then I will replace the ECU. Going the cheaper route. And if the used ECU does not help, I will get a new one...