Ok guys someone tell me what the differences if any between the S4, S5, TII and NA ECU's are I have a S4 TII with a bad ECU and I plugged in an S4 NA ECU and it fired right up it doesnt run all that great but some one give me some info on interchangeability. Thanks

 

I think if its the same generation (ie s4, s5, s6) theyre all interchangable, but you cannot mix and match between gens

 

no... harnesses are specific to type of ECU. ECU's are only interchangeable between sub model.

For example. A N332 (87-87.5 Turbo) ECU would only be compatible in a N33X car, (87-88 Turbo) and could be interchanged with a N332, N333, or N338 ECU.

Conversely a N37X series ECU would only work in a N37X car (89-91 North american spec Turbo). You could not put a N370 ECU into a N332 car without changing the engine and dash harnesses.

Or a N326 (non turbo 86-87.5) ECU could only be used in a 86-88 non turbo car, but a N327 ECU (87.5-88 non turbo) could also be used.

See the first three digits must match the cars engine harness and existing ECU.

And all of this has been covered countless times as well as can be found in the 2nd gen archive. Please use the search function found in the upper right hand corner of the page before posting.

 

thanks for clearing that up ice

 

So what about the fact that I have an 87 S4 NA ECU that plugs into my 87 S4 TII harness are the maps going to be different?

Also which N33* series ECU has the best performance map?

 

Stock maps on a N332 and N333 are almost identical with the only difference being the N333 is set up for saturation injectors, while the N332 is set for Peak and hold injectors. Completly interchangeable though and no performance gain using one over the other.

And the NA ECU (N326 or N327) will not work the same in that harness. There are some substantial differences on how the load inputs work between the two. You might be able to run the car temporarly on a Non turbo ECU, but the engine will suffer for it. Only the N338 would work both a non turbo and Turbo motor correctly with minor wire swaps.

Remember the N326/N327 ECUs do not have the inputs for the knock sensor, or the outputs for the twin scroll system.

 

S4 and S5's are different

but i know you can use a s4 auto ecu on a s4 stick, but doesnt run to hot.

 

Thanks guys thats exactly what I needed!!

 

Ah, that is wrong.

There is no such thing as a S4 auto ECU, or a manual tranny ECU.

All S4 non turbo FC's of the same year used the same ECU regardless of tranny, and added a auto tranny controller box that hooked up with two wires to the ECU.

For example if you had an 88 GXL with a auto transmission. It used the same exact ECU as the 88 GXL with a manual tranmission (the N327) or the 88 GTU (that only came with a manual tranny).

Or if you had a 86 Luxury Coupe with auto tranny, it used the same ECU as the 86 Luxury with a manual tranny (the N326).

Please do not post if you do not know. Wrong answers can hurt more than just your ego, but can hurt your fellow members pocketbook.

 

I have a 89 Convertible ECU that went out, what did they do different to the ECU for the convertible that would keep me from using a regular 5 speed NA ECU? (N350 instead of the stock N353?)

 

Hey so I have 88' convertible rx7 thats not turbo'd, but the ECU is n338, is that possible? That's how I picked up the car it's not running currently and I'm trying to figure out whether or not I need a new ECU and what types are interchangeable with the car. Any info would really help!