can i use RB25det series 1 ECU in a series 2 motor?

[zephyro90]

i busted my series 2 box due to faulty wires. we have corrected it. we cant repair the old box (series 2). i was able to source out a series 1 box, can use this on my sereis 2 engine?

thanks happy new year!

[Carl H]

no.you can use a series 2 ecu on a series one engine but not a series one ecu on a series 2 motor.pfc might be a good option if you cant source a stock ecu.

[eh?]

Why can't you use the S1 on the S2? doesn't make sense if the S2 ecu on a S1 works and the fact that the pfc and ems work with either without any changes.

[zephyro90]

yah... why not?

dont they share the same harness?

[Carl H]

im not totaly sure why, but i remember while crusing SAU that some guy tried a s2 ecu on his car and it worked but the s1 on his friends car didnt.it would be safe to assume that nissan built the backwards compatability into the s2 ecu for those weird 'mid year' cars such as the s1.5's.........go figure.

[zephyro90]

even if i still use the S1 harness?