Hello everyone, I'm new to the forum and new to a sc400 I took on a trade. These are very nice cars considering they are 20+ years old. Although I'm having problems with this one.
I had a cel and pulled the codes for maf sensor, iat sensor, and rpm signal.
Now I replaced the maf with no luck, still jerking and cel, but unplugged does ok. Also Trans shifts fine until wot and then will not shift into next gear? Hope it's not on its way out. Fluid is spot on. Upon looking over the car I noticed a repair manual that had a sticky note in the section with ecm replacement, go figure so that's what I'm leaning towards for the above problems but would appreciate some advice. Who is a good vendor for ecm rebuilding? Thanks everyone.
95 sc400 180,000 miles.

 

Rebuild the ECU. Tanin Electronics here on the forum are excellent and quick. If it were me, I wouldn't replace parts until after the ECU is rebuilt. From what i've noticed, 90% of SC400 transmission problems aren't due to the tranny, but the ECU.

 

Thanks for the recommendation, I'm believing more and more it is my ecu, is it safe to pull of ecu and leave off until ecu is rebuilt? Repair manual says you have 90min of working time??

 

People send their ECUs off for repair or buy used ones all the time. Obviously, that far exceeds the 90 minute window (which is news to me, anyway; memory is cleared much quicker than that, I believe). I had mine out for the weekend for local repair and didn't have to do anything after reconnecting it.

 

I also thought that was odd but I didn't want to do anything I wasn't sure of, just going off what the manual said. Hopefully someone that has had one rebuilt or a rebuilder will chime in so I can mine rebuilt

 

When I sent mine off to be rebuilt, it was gone for almost a week. The car sat without an ECU that entire time. Started right up once I installed the ECU. You should be fine.