Had an 06 rev up motor put in my 05 G coupe (rev up) and they can't get it started. The mechanic it's at now thinks he narrowed it down to the ecu. From the research I've done I've read you have to replace with the same year and trim and everything so my question is do I use an 06 ecu to match the motor or 05 to match the car?

 

From what I recall, I believe the last few numbers of the ECU needs to match the motor. Did you get the keys reprogrammed? NATS might be preventing you from starting it up.

 

I thought the engines were the same? You can't just swap it like that? Wow

 

Yes, according to nissan's tech line, the ECU's are "somewhat" engine specific. You don't need the exact same ECU but it needs to be one that is similar for that model/yr.

 

@bythabay yeah we had two different locksmiths reprogram the keys with no luck. I think I may try to get an 06 ecu since I have an 05 now and it's not starting.

@jaE35 they are the same motor but like I said most people say the ecu needs to be very specific.

 

That just does not make sense to me. How does the ecu know what difference there is if the motors are identical?

 

I have never heard of the ECU being "that" specific. Relative to same year/engine/trans it should be the same. There are a few differences with some of the MAF sensors used in the models in the past. I wonder if thats why?

 

Yea but if you use your old engine harness nothing should be different

 

Thats most likely reason. If ECM replaced it needs to be reprogrammed by dealer, unless ECM is a virgin unit.

 

ECM or do you mean ECU?

 

This seems to be an on going issue.

Nissan/Infiniti FSM refers to Engine Control Module not a Engine Control Unit.

 

@jaE35 We used the same harness

@hotrodg35 I haven't changed the ecu yet, I'm wanting to. If I do, you're saying only the dealer can program it to my car or can I just have a locksmith come out to program the key?

Honestly I'm open to any suggestions at this point, this this has been so aggravating, been over a month with 3 different mechanics going through everything and it's still not starting. It cranks but that's it, there's no spark at all to the coils

 

I had to replace the ECM and required reprogramming by dealer. Not sure if your existing key can be programmed to the new ECM by a locksmith.

Was originally confused by your post with ECM. If the ECM has not been changed and is matched to your existing key than it maybe an issue with sensors on new engine.

Did you check Crank Sensor and Camshaft sensors on new engine ? or were the sensors swapped from old engine ?

 

Yeah I'm not sure either, guess I'll just ask the locksmith if I do end up getting a new ECM. My mechanic is now telling me he had my current ECM checked by some electronics specialty shop and they said it seems to be fine. We may still end up getting another one because it seems like there's nothing else it could be.

Yes the crank and camshaft sensors were checked and are sending signals to the ECM.

 

did u ever figure out the issue man ? u swapped ecu or flashed it ?