I believe the ecu with the part number ending in 840 is for 94-95 motors and 841 is 96-99.
if it helps
my car is a 1996 model, my original ecu is the 841. i'm now using a power fc plug in ecu which came out of a 1994 wrc model.
both 1994 and 1996+ models are both Non-OBD toyota propietry diagnostics,
there are some minor differences on the dash like bulb locations and features plus airbags were introduced in 1996, interestingly 94 dashes have an unused 4WS bulb socket while 96+ ones have unused TRC off and skid bulb sockets. some of the cars electrics are very slightly different, -but- i have no clue if any of this makes a difference, maybe, maybe not.
neither jdm 94 nor 96+ models have egr.
can't really tell if the tune is any different
im guessing there is a possibility that one of the wires may be different, in this case, it could be best to get the one for your year range if purple ^^ up there is right -OR- maybe best to get the 1994 version since thats what all the wiring diagrams seem to be based on ??? just some thoughts anyways
Mike W1996 Toyota Celica ST205 GT-FOURGT2860RS turbine, TiAL mvr44, JE 86.5φ piston, Clutchmasters FX400, APEX P-FC269awhp / 273ft-lbs
89661-2B840 is pre august 1995 JDM 89661-2B841 is post 1995 JDM there is little difference the earlier ecu was fitted to the WRC's
Thats what my friend gottagoturbo told me ^^^^^
I imagine it doesn't changes much. Like the abs and some small stuff.
The tune should be the same since the engine was the same.. I belive
Thanks a lot delusionz and purplegt4
yeah i'm pretty sure my abs still works btw lol
Mike W1996 Toyota Celica ST205 GT-FOURGT2860RS turbine, TiAL mvr44, JE 86.5φ piston, Clutchmasters FX400, APEX P-FC269awhp / 273ft-lbs