deanshark

I know this has probably been asked in the past but I couldn't find it. I have an opportunity to get a 94 Ca. spec ECU cheap, and close. My car is 94 federal spec. Just wondering if the federal and Cali spec ECUs are interchangeable. I know they're not exact cuz the Ca has more smog stuff? I don't have the numbers off either one cuz they are still installed. If they do work I don't care if there's a CEL, that won't bother me with all the other lights I have. TIA

Yamae

Your car runs but the torque is a bit less when you use a Cali spec ECU for a federal.

deanshark

Thanks Yamae. A little torque I can do without as long as when I step on the gas it doesn't die. I'm going to pick it up in the morning, it's only 30 miles away. I just hope I can drive my car on the highway in the condition that it's in. I'll drive back with the new (used) one in. I found today in another thread, from over 10 years ago, (Thank you search feature ) where the guy ( 3UZTaco ) switched the federal ECU for a Ca. ECU and said

"it works fine with the exception of setting code 48 (air pump). I put a 1k resistor across the appropriate terminals to cure that and all is well."

Maybe I'll have to figure out what terminals he's talking about and try that, although the CEL wont bother me if I can't. I'll let ya know how it feels and runs when I get back.

peterls

Following this out of curiosity: what is an "air pump"? (pardon my ignorance)

deanshark

I have no idea what it does exactly cuz it's only on the Ca. cars so I never had a need to learn about it. It's actually a "secondary" air pump. Something with your crazy Ca. emissions.
I'm just waiting on a call from the junkyard to tell me they pulled the ECU. I hope it's soon cuz it's already 87* and I want to see how this thing works in the heat. Supposed to only be 55* tomorrow. Crazy New England weather. I'll let ya know how it works later.

deanshark

Well, I went up and took out the ECU out of the junkyard car. Wow what a parts car. Other then the hood and grill I'd say it was a 9.8 out of 10. Black interior with not 1 scratch on anything. Exterior the same, black and mint.
It turns out it's the same federal ECU that I have, not the Ca. ECU like I was told. Same part number 89661-50142. With it being around here it could have been changed out already just not needing the Ca version anymore. I've already noticed a little bit different. At highway speed I can feel a little hesitation at steady throttle like a skip. And at idle, very hard to notice, it seems like the RPM is up and down only about 20-30 RPM. And taking off from a stop sign it doesn't go like a rocket like it should, til the RPMs get higher. Maybe I just need a tune up. (plugs, wires, caps, rotors) I might not have noticed it before cuz I had bigger problems caused by the ECU. Eh, at least I can drive the car normal now without having to shift manually and not have to worry if it's gonna die when I hit the gas.

Sorry to peterls and whoever else wanted the answer if the federal and Ca ECUs were interchangeable. I don't have the first hand experience but, post #4 in this thread says they are. https://www.clublexus.com/forums/ls-...0-bad-ecu.html

peterls

Thanks for the update deanshark and I'm glad it worked out that well for you! Nothing better than getting a part you never expected to get
As for your hesitation issues, from what I have observed on this forum, when it's the ECU, there are more than just slight engine issues. Usually it involves a whole bunch of gremlins, until you replace the capacitors in the ECU and then, suddenly, everything's back to normal. No guarantees, but that's what it usually looks like, so as you say - I'd start with spark plugs, wires and such.
Oh, btw, I know I sound like a broken record, but just flushing my cooling system with Prestone (then refilling with Toyota red liquid) and replacing the thermostat (with the one from Lexus), my car drives even better! It also runs better in cold weather here in N. California. Something to consider, I guess.

deanshark

It was 42* this morning and the car ran pretty good, better then yesterday. Maybe cuz it was cold or it had to "learn" the car. Either way winter's here, sorta, so I'm good for now.
Funny thing though, after putting in the new ECU my A/C finally started blowing cold. Not freezing but not heat like it was. (now that I don't need it)