Will a 91-93 Q45 ECU work on a 94 Q?

[Kiven422]

Like the title says is it possible to interchange these parts?

[elwesso]

Yes

[maxnix]

Yes, but it misses out on a few things the later car has like the dual speed auxiliary fan.

[qship96]

As Brian noted, it may plug in and somewhat work, but the engineers tweaked the ECU numerous times over the years{sometimes many times in the same year},so best to stick with factory part # for ECU based off your VIN number.

[elwesso]

Ive ran a 91 ECU on my Q for the past year or 2... Take that with whatever grain of salt you want, but my Q still moves on its own power...

[qship96]

Ive ran a 91 ECU on my Q for the past year or 2... Take that with whatever grain of salt you want, but my Q still moves on its own power...

Nobody said it wouldnt WORK,just not AS DESIGNED. Actually,your Q doesnt move on its own power....you are on YOUR THIRD ENGINE!!!!

And lets not even bring up your first Q, gone to an early grave....

[Haitian_King]

Ive ran a 91 ECU on my Q for the past year or 2... Take that with whatever grain of salt you want, but my Q still moves on its own power...

The NICO Stage II ECU I got with Wes' autograph on it is from a 94 according to the writing on the case. Throwing a '94 reprogrammed ECU into a '92 won't be bad right? I haven't installed it yet.

[maxnix]

16 bit vs. 8 bit shoudln't matter, but don't know what will happen when it tries to change auxiliary fan speed on 2 speed later model fan.

[elwesso]

The NICO Stage II ECU I got with Wes' autograph on it is from a 94 according to the writing on the case. Throwing a '94 reprogrammed ECU into a '92 won't be bad right? I haven't installed it yet.

No not at all, it will work great...

Nobody said it wouldnt WORK,just not AS DESIGNED. Actually,your Q doesnt move on its own power....you are on YOUR THIRD ENGINE!!!!

And lets not even bring up your first Q, gone to an early grave....

Hopefully I dont need to point out anything to show the irrelevancy and daftness of this comment.

[Haitian_King]

Thanks for the info Wes.

[qship96]

[QUOTE=elwesso

Hopefully I dont need to point out anything to show the irrelevancy and daftness of this comment.

[/QUOTE]

I stand firmly behind my comment.....just because something "works", or "fits" does not mean it works or fits as designed, and will not degrade or damage, or even ultimatly destroy your car.

Will 20" wheels "fit" your car? YES, but seriously degrade the ride, possibly damage the shocks and suspension due to the added stress

Will those super stiff ESPILIR springs "fit" your car? YES,with the same downsides as above, possibly much worse

Will a 90-92 ECU "fit" or "work" in a later 94-96? YES,but not as designed and the possibility of damage or destruction of the engine due to different programming and the lack of the condenser multi-speed fan controller programming/control

Will performing all kinds of mods to the engine, even though they "fit" and initially "work" ultimatly shorten its lifespan, degrade,damage,or possibly destroy your engine? Well,you just gotta ask yourself Wes,why is my car on its THIRD engine,while others get 300K easily out of theiroriginal?Doesnt take a rocket scientist to see the long term results of the modifications made to the motor and the end results of trying to outsmart the engineers who designed it


Modified by qship96 at 2:38 PM 2/2/2008

[Haitian_King]

I stand firmly behind my comment.....just because something "works", or "fits" does not mean it works or fits as designed, and will not degrade or damage, or even ultimatly destroy your car.

Will 20" wheels "fit" your car? YES, but seriously degrade the ride, possibly damage the shocks and suspension due to the added stress

Will those super stiff ESPILIR springs "fit" your car? YES,with the same downsides as above, possibly much worse

Will a 90-92 ECU "fit" or "work" in a later 94-96? YES,but not as designed and the possibility of damage or destruction of the engine due to different programming and the lack of the condenser multi-speed fan controller programming/control

Will performing all kinds of mods to the engine, even though they "fit" and initially "work" ultimatly shorten its lifespan, degrade,damage,or possibly destroy your engine? Well,you just gotta ask yourself Wes,why is my car on its THIRD engine,while others get 300K easily out of theirs?

Ouch. C'est chaud, c'est chaud, c'est chaud!

I get what qship is saying about the 90-93 ECU not being optimal for a 94-95. My question is, "Will a 94 be detrimental to my 92?". I'd like to think that it is backwards compatible and will function well in the earlier model years, but I'm not 100% sure on the differences between those years. I know that the 94-95 was 16-bit and the 90-93 was 8. Running a 16-bit of a car designed for an 8 can either be ok or really bad right? On the converse side, running a car designed for 16-bit with an 8-bit controller either doen't hurt, or is bad. Right?

[qship96]

We all could guess at it all day long, but you got to ask yourself this simple question......Why would Nissan take the time/expense/shelf space/production costs to specify different ECU part numbers based off model year{and even multiple different ecu part numbers within SAME year based off individual VIN #} if they were all the same? THERE IS A REASON

Problems surface, big and small, when owners think they are somehow smarter or more experienced than the engineers who designed the car

sometimes a little knowledge is a dangerous thing...............

[Haitian_King]

So I guess the best choice for a modified ECU is one from your model year?

What about the JWT ECU's?

[qship96]

I have no knowledge of the modded ECU for the q45

Couldnt tell you what parameters have been tweaked and the upside or short/long term downside that results from this modification

Age,wisdom,and experience tells me their are always tradeoffs to every modification we make...both good and bad they come as an inseparable package

[elwesso]

Not to toot my own horn, but im pretty sure I have more experience with ECU's than anyone who's posted in this thread. Just throwing it out there.

No reason to beat a dead horse because the information is out there... Just a quick note on the fan though.. The fan is designed to come on at 221F which is well in the "overheat zone" according to the computer. The ECU can only put the aux fan into high speed mode, low speed is only controlled with the AC on, which comes on with the engine temp at 203F.

If your Q is running properly the ECU probably wont turn that fan on anyway, and if its that hot the AC will probably be on, and if it is then the AC control will probably turn the fan on before anything else happens.. you should never hit 221F and if you do something is messed up pretty bad, which of course means you shouldnt be worrying about your ECU but how your cooling system is messed up.

This is basically the only difference in the ECU's, or the only one that is appreciable, which IMO its not really that important. They really changed a lot inside the ECU for very minimal net change.

If you can live with the above (I can), then go for it. If you cant, then dont do it.

Im pretty sure that running 275 shot of nitrous and swapping ECUs between years are apples and oranges.. Which, BTW, both the first and second engines RAN when they were taken out. The first engine was just ragged out, the second was a bad motor to start with.

[Haitian_King]

Not to toot my own horn, but im pretty sure I have more experience with ECU's than anyone who's posted in this thread. Just throwing it out there.

No reason to beat a dead horse because the information is out there... Just a quick note on the fan though.. The fan is designed to come on at 221F which is well in the "overheat zone" according to the computer. The ECU can only put the aux fan into high speed mode, low speed is only controlled with the AC on, which comes on with the engine temp at 203F.

If your Q is running properly the ECU probably wont turn that fan on anyway, and if its that hot the AC will probably be on, and if it is then the AC control will probably turn the fan on before anything else happens.. you should never hit 221F and if you do something is messed up pretty bad, which of course means you shouldnt be worrying about your ECU but how your cooling system is messed up.

This is basically the only difference in the ECU's, or the only one that is appreciable, which IMO its not really that important. They really changed a lot inside the ECU for very minimal net change.

If you can live with the above (I can), then go for it. If you cant, then dont do it.

Im pretty sure that running 275 shot of nitrous and swapping ECUs between years are apples and oranges.. Which, BTW, both the first and second engines RAN when they were taken out. The first engine was just ragged out, the second was a bad motor to start with.

Well then. Guess that about says it all eh?

[Kiven422]

Ahh thank you guys for the info.

Is it possible for me to re-flash my ECU myself or at least tweak it?

We all know the 94-96 Q45s are slightly less agresive powerwise due to many factors, but is there any possibility of having more power with a 90-93 ECU...?

[AlabamaDan]

The NICO Stage II ECU I got with Wes' autograph on it is from a 94 according to the writing on the case. Throwing a '94 reprogrammed ECU into a '92 won't be bad right? I haven't installed it yet.

No No No. Don't use that. But, not to fret. I've got a 94 we can plug it into. I think you'd be better off with everything that's been said by passing that on to me and Getting Wes to build you a 92 ECU.

[Haitian_King]

No No No. Don't use that. But, not to fret. I've got a 94 we can plug it into. I think you'd be better off with everything that's been said by passing that on to me and Getting Wes to build you a 92 ECU.

Yeah? Maybe when Wes gets a chance. I still have my nice shiny '92 ECU in. The '94 one looks like it was beaten with a stick.