We'll, as some may have seen my previous thread where I was trying to diagnose a starting problem I was having with my 1993 SC400 w/ 150K.
Here is the thread:
https://www.clublexus.com/forums/sho...d.php?t=266539

I finally gave up and sent it to the dealer to have them check it out. Well, after a diag, they've determined that it was the main ECU. They want $1240 for parts and labor

They are not sure if its anything in addition, but that my main ECU is bad. Car wouldn’t start unless its jumped from another car. Changed battery, cleaned terminals, wires, dist./rotors, coils, fuel ECU, tested fuel pump, etc, and still nothing.

Anyone ever had this problem before? And are the SC's ECU all compatible? (I plan on doing this myself) or do I have to get one from the 1993 model specific? I know on some domestics, there different ECU for the same year... designated per ECU code.

Anyone have any part numbers? Seen a few on eBay, and didtn want to pull the trigger until I was sure they are going to work.

Will be picking up my ride from the dealer tomorrow hopefully, Thanks guys.

 

If you know someone lese with an early sc400, try their ecu. It wouldnt take long. If thats what it is, you can pick one up cheap from a junkyard.

Use the $1200 to take a cruise, or something.

 

I know John, laxdude, had a problem similar to this on his sc300 and had to get the ecu replaced. The car would turn over, but would never start. Not sure if it could be related in any way with two different engines, but just so you know you're not the only one that this has ever happened to

 

anyone out of a pre 95 400 should work.

 

pmed i have a spare ecu

 

THanks guys for all yoru help. As soon as I typed this, i got a few PM's about ECU's... I'm really hoping this will end the two month long problem with my SC.

PM's replied. THANKS.

 

Hi Grand. Sorry to read about the issues you've been having; sounds like it's been rather aggravating. I'm sure your posts will end up helping others, though.

Did the dealership give you any specifics on the ECU diagnosis? I just wonder if that's the only problem, since the ECU could have been fried by the broken wires you found (depending on what they were.)

Also, it sounds odd to me that you were able to jump-start the car; this would typically indicate an electrical load issue, and I'm having trouble understanding how the ECU would play into this.

 

^ We all are. Hes been into this thing for so long. Replaced/Checked almost everything. The only thing I can think of he hasnt done was the starter solnoid, but it cranks just fine.

 

Yeah I had the exact same thing happen to me in the first few months of owning the car. Ended up replacing the ECU at the dealership. Pricey, but hey it fixed it.

 

Did the dealership explain why it was the ECU though, or what was specifically happening?

 

Car would crank, but not start. Everything checked out to be fine, so they determined it was the ECU. So once the ECU was replaced the car started and ran perfect.

 

I have an ECU, as far as i know it works fine. Let me know if ya want it.

 

Just got the car back from the dealer… they couldn’t even start it with their jump boxes… and wondered how I was going to take it home. I told them to push it outside the service bay, and I’d show them how its done (they were trying to jump it from their boxes… and it needs another running car to jump it) pretty strange huh?
Thanks, I’m hoping this could shed some light, for future reference. They actually didn’t give me any specifics, just said the ECU was bad. btw, wire I found was an ignition wire... solved a problem I had when I could get the car to RUN. (wire broke during the fiasco (I guess everyone kept pulling it in and out, and checking it.... and with age it broke... so I didn’t know it was an ignition wire at first, thought it was related to the car not starting problem, because it happened while i was test driving it).

LOL, I got to know the entire neighborhood, seeing them go, and come back from work while I was still working on the car. So whenever im outside washing my other cars, the neighbors pass by and ask me if I figured it out yet, and we just sit there and scratch our heads.

Wow, I’m glad to hear that the ECU fixed your problem. I figured when its something that doesn’t make sense like this, its got to be an ECU somewhere. There I have a SC, with a brand new headlight lenses, front bumper, lip, and it doesn’t start… just sad to see it sit there.

I know the question was directed to laxdude... but as I mentioned before, they didn’t say anything to me... just bad ECU.


PM sent. Thanks guys for all the input

 

FIXED

Finally got my ECU yesterday, put it right in, and she started up. The car is now running fine. Real glad it worked out.

Now im not sure if its directly related, but my compressor is not operating anymore, which is very strange, since it was just fine before all this happend. I dont know if this is age related, or due to all the cranking that she went through at the dealer, and bodyshop. The clutch seems to be stuck... Hopefully I can get this fixed before the summer.

Thanks guys for all your help!~

 

It's good to see everything worked out well.