I've got an 03 AT LS that I need to get a new ECU for. The part number on mine is MR988331. I found one from an 02 AT LS but the part number on it is MR578489.

Since the engines are the same, wouldn't the ECU from either year work just fine?

 

ask RRM, i'll bet they know for sure.

 

they should b same...but like ^^^ said...check w/ rrm...waht happened 2 ur original ecu???

 

there haven't been any recalls for ecu reflashes, but they do exist. the new part numbers may just mean they're updated, but should otherwise work.

 

WIth the Mirages, certain ECUs had more aggressive timing, more advanced fuel maps and removal of limiters.... maybe there are slight changes between the years. It should still work back tho.

 

Isn't an automatic's computer called a PCM not ECU..

 

Yeah, the Cali spec tunes are less aggressive than the national tune. I don't know if there's a difference by year however.