Why Arent S2 And S1 R33 Ecu's Interchangeable

[wallas]

Hey guys are there different plugs associated with the ecu's between r33 s1's and s2's? Just trying to clarify why they are not interchangeable esp in regards to aftermarket ecu's.

Edited May 25, 2009 by wallas

[d_liberate]

The stock ECUs arent interchangeable (correct me if I am wrong). I think it has to do with the base tuning? The AFMs and Cams are different to one another (as well as coil packs) so require a different setting etc....

For aftermarket ECUs however, the plugs are defintely the same as each other as the Apexi Power FC fits both S1 & S2 ok.

[Conrad 2NR]

Won't have anything to do with the ignition amplifier setup being different would it?

[mitchy_]

both are external to the ECU, S1 has external ignitor, S2 has ignitors in the coils.

S1 and S2 ecu's are interchangable

[Conrad 2NR]

I thought only the S2 ECUs were backward compatible whereas the S1 would still need the external amplifier for it to fire the coils.

[mitchy_]

they both have an ignitor that is seperate to the ECU, therefore it doesnt affect it.

the S1 has an external ignitor, and then 6 coil packs, S2 has 6 coil packs with built in ignitors.

[Conrad 2NR]

Talk about learning something everyday.

[mad082]

i have used a s1 ecu in a s2. worked fine

[wallas]

i have used a s1 ecu in a s2. worked fine

i guess itll work then. Lets hope for the best..

[bryce19]

and i have used s2 in s1 with no problems

[R31Nismoid]

The stock ECUs arent interchangeable (correct me if I am wrong). I think it has to do with the base tuning? The AFMs and Cams are different to one another (as well as coil packs) so require a different setting etc....

For aftermarket ECUs however, the plugs are defintely the same as each other as the Apexi Power FC fits both S1 & S2 ok.

Different CAMS? Oh come on... thats just silly.

They are the same.

ECU's can be changed between no problems, even Auto ECU's in the Manual work fine

[d_liberate]

R31Nismoid - thankyou for correcting my wrongness, and so subtle too.

witth the cams though, why are Tomei poncams not interchangeable between the series 1 & 2? Isnt that to do with the crank angle sensor being different in each model? Or am I just being silly again?

[paulr33]

mythbusters ahoy

as the guys have identified already, the main notable difference between series 1 and series 2 is the coil setup

this however, means nothing to the ECU, as the changes (between s1 and s2) are done on the engine loom side, so its transparent to the ECU

all of the sensors, dials, meters, voltage ranges etc are the same, and operate the same, there is no difference

there are other notable differences such as 4wire AFM vs 3wire but again, this is engine loom side difference, so its transparent to the ECU

an issue does however occur, when say on a series 2 skyline, you plug in a series 1 ECU and the MER (or MEC?) chip is different

from memory this is the main hitachi chip on the board. there are a few variants for S1 and for S2

if you use the wrong one, the car basically runs like a bucket of crap, sluggish, slow and doesnt go hard

there are no sensor errors, no warning lights, no backfiring etc when this happens, it just runs sluggish

why it happens, i dont know, its something to do with the MER (or MEC?) chip being the wrong model - ask toshi, he knows what it is, and why it goes sluggish

there would be minor minor differences in the map data between s1 and s2 but these differences would be neglibable

ie, you wont loose power or make magical rwkw by using a S2 ECU on a S1 R33, or vice versa

much is the same if using an Auto ECU on a manual car etc or vice versa

it will work and run ok, but you may find the Auto ECU expects "auto" gearbox signal, so it might throw on the engine check light

or it might refuse to start (its waiting for the auto box to say im in park) or you might find VCT wont engage (as VCT wont engage until the car is in gear, must NOT be nuertral)

so in summary

interchanging is OK - but check how the car drives

interchanging auto to manual is OK - but not recommended - why would you bother? its just a headache

in all cases its by far easier to source the correct ECU for your car, in all cases

the stock ecu is worth $10

aftermarket ECU's copy the stock ecu (they must, to work corretly) so a plug and play ECU will be the same

ie; its no difference s1 or s2 and it works the same

[wallas]

well done mate.. thanks alot

[Toshi]

S1 and S2 diffrent throttle senser.

S1 ecu and S2 ecu is diffrent program.(almost same map but progam is totaly diffrent)

Engine will start but ecu is not working properly.

[maximajim]

S1 and S2 diffrent throttle senser.

S1 ecu and S2 ecu is diffrent program.(almost same map but progam is totaly diffrent)

Engine will start but ecu is not working properly.

But why and how does the ecu know there is a difference?

[paulr33]

it physically looks different (there is an extra plug on the series 1 TPS) but i dont know of any difference in the ECU logic etc?

ie the voltage range is the same, it works the same, it functions the same, but the phyiscal appearance is difference

find a photo of a s1 throttle body and s2, youll note theres an extra plug

[da spike]

just get toshi to remap the ecu dont risk getting a ebay ecu...

[maximajim]

it physically looks different (there is an extra plug on the series 1 TPS) but i dont know of any difference in the ECU logic etc?

ie the voltage range is the same, it works the same, it functions the same, but the phyiscal appearance is difference

find a photo of a s1 throttle body and s2, youll note theres an extra plug

On what the tps? The s1 also has the extra connector on the tps body, it just goes to the tcu if you have an auto.

Edited May 28, 2009 by maximajim

[paulr33]

yeah thats what i meant sorry, the extra plug on the TPS body

do you know why this isnt present on the S2 ?