Question

what is the difference in part numbers on the ECUs?
my 1995 Sov had an ECU that matched the cars build date of 2/95 so likely original ECU with part number LNA1410GF/301
my parts car 1994 Sov had an ECU that was obvious replacement being build date 8/95 (1 year after car was built) with part number LNA1410WB/301
has some warranty stickers on it, looks like it was potentially refurbished

now obviously they are interchangeable my 1995 runs perfect with the new ECU. my question is what are the likely differences and what do the differences in part numbers mean?

BACK STORY.

So I had a big issue today when I went to drive, the cat would not start.
it was starting then instantly dying.
it would run if I pushed the accelerator but then die as soon as I took my foot off.
the car seemed to have unburnt fuel coming out the exhaust so I put it down to a bad airflow situation.
swapped out the MAF from my parts car, no improvement.
then I took out the IACV and swapped it out, still no improvement.
so I got the IACV and manually wound it open more, and it would run with high idle, but if I plugged it back in after a few restarts it was back to dying.
so at this point I know that the car is just not getting enough air and unable to maintain idle.
so I take the ECU from my parts car and swap it in, she starts and runs beautiful.
take it for a drive and it is idling good but when I try and slow down the revs drop too low and she stalls every time I try and stop.
so I go home, swap the IACV back to the one that was originally in the car and now she drives perfect.
idles around 800ish in park, and down around 650ish when in drive.
nice beautiful stable idle.
drives like a charm.

so now I get my ECU and put it into my parts car and start her up,
and well she runs, it is keeping her alive but it is idling in park way down at 500rpm.
and when accelerating it revs ok but runs rich and blows a lot of white smoke, then take the foot off and the revs dip and she almost stalls
so obviously there is something wrong with the ECU and it is not supplying enough air.
parts car ran perfectly before swapping the ECU.
now I don't mind it doesn't run well, it is a parts car after all, just great that she is still mobile.
maybe a TPS reset would get the idle set to right for this car but that is not something I am looking to do anytime soon.
maybe later if I decide to also fix this car and have them both on the road.

 

The North American market had a Service Action/Recall and I replaced DOZENS and DOZENS of PROMs during the campaign.
The differences in part numbers were simply the PROMs installed in the ECM.
Here is the TSB we received at the dealer.(for information)
Other Countries probably were NOT affected?

 

Australia would not have been affected as we do not have EGR on our cars.

 

Interesting, it is good to have a parts car. Your old ECU might be failing! Value added for the parts car. Very fortunately it seems like the two ECUs have the same O2 sensor and TPS settings.

Certainly the benefit of parts swapping when there is a problem. I did that a lot with my X300s back in the day.

 

certainly already showed me how nice it is to have a parts car. maybe having my accident was a blessing in disguise in that sense.
just knowing i have the ability to swap out and test parts makes diagnosis and repair so much easier.
it does seem like the old ECU is failing, it is barely allowing the parts car to idle.

the tps setting seems to be very slightly different between the two. but negligible.
got lucky there. was surprised at how smooth it runs with the ecu sawp.
car is idling at something about 675rpm instead of just over 600 where it was.
at some point I might take it to get adjusted but it is not a major concern right now.