All,
My '94 SC400's memory seat settings don't work and I can't figure out why.
A Lexus tech and I went over the schematics and found that the ECU under the driver's seat controls the memory seats, as well as a few other things (e.g., steering wheel memory setting, power seat controls, etc...); it also uses the same fuse as the brake lights. Well, EVERYTHING works but the memory seats. I have a backup ECU I was going to try and swap out to see if it works, but after that the only thing I can think of is a loose wire in the door.

Any other experiences with this problem? Solutions?

 

I have this same problem. The seats do not work but the steering wheel does.

 

does anybody memory seat work?

 

Guys,

My seats work wonderfully! My mirrors will work the same after I get my Mirror ECU from GAZI ALI. He is the man. Usually a mech, like Gazi, can save you a bunch of time finding a problem due to their experience. Look for an experienced expert. Your comment about tracing every wire with a dealer shop tech tells me you are the guy that will solve this problem even if it so unique it has never before nor ever will again repeat. That is a sincere complement. My money is on the Seat ECU with a backup bet on the connections to it. Very old "electronics technicians" saying...A good visual inspection is worth a thousand tests". Spread pins in the socket and bent/missing pins in the plug are toughies. All of the troubleshooting and logic flow diagrams do not address wire or plug failure. There is only a statement at the end that says that your problem is in wiring.

I think you are going to fix it with a module replacement.

Good luck.

John

 

I have encountered this with 2 of the coupes in my past. One had an alarm installed when I bought it, bypassing the factory alarm. Removal fixed the memory seats.

After the remote start was installed in another the function disappeared except for when the factory alarm was enabled.

Can anyone else chime in? I believe the problem can also be associated with the RKE or the factory alarm ecus.

P

 

Anyone? My seat presets don't work either... nor does the power mirrors... Where is this ECU you guys speak of, and where can i find them?

 

Poor Baby,

The R&R proceedures starts off with disconnect the bat. Then the drivers air bag. Then the steering wheel........get the pic? The mirror ecu is above and forward of you right knee. You can unplug it if you remove the lower section of the dash. Then you can plug in the ECU that GAZI sends you and make sure it works befor you launch into the full change out.

Maybe the seat not working also changes the logic. Only an experienced mech can give you advice on that.

Good luck with this and let us all know.

John

 

I'm not sure about the mirrors..JohnEd sounds like he does, so go with him on that.

The power seat, memory function, tilt steering wheel (I thought the mirrors), etc... are all tied into the seat ECU under the driver's seat; just unbolt the seat and tilt it back to reveal the ECU under the cushion. You can't run a diagnostic, but you can verify its connected properly. A disconnected wire in the door sounds like a good candidate (see 933005spd's solution), I haven't tried to fix it yet, but I plan on doing so this weekend...I'll let you know how it goes. If that doesn't work, then it is probably a short somewhere in my seat ECU. If all of the other related functions (e.g., steering wheel memory setting, power seat controls, brake lights, etc...) work, then it narrows the problem to the actual memory button assembly or connections to and from it. It sounds like a lot of folks have written this function off as an "SC thang", but I'm too stubborn to give up...besides I hate it when I have to readjust my seats when the wife hops in occasionally.

 

you might be right it can be a wire in the door or something .im gonna operate on mines this weekend and see if it is the wires .did anybody try changing the buttons to see it thats the issue?

 

I had the same problem with my sc400...after i removed the driver door panel and reconnected the seat buttons, they worked perfect. i assume someone forgot to reconnect them when they last had the door panel off.
Moral of the story here is always start with the simple stuff.

 

mine still dont work, should ve made this a poll lol

 

any updates on this?

 

Just had the window regulator replaced and when I was putting the panel back on I made sure to connect the wire harness to the buttons and now the memory seats work perfectly. I don't remember unpluging it so it was probably left disconnected when the previous owner had the panel removed for whatever the reason.

 

Okay so i posted a LONG time ago that my seats didnt work either.. k so i changed the seats in my car from a 97 (i have 92) and when the key is on, the memory seats dont work. (i can set them, hear the beep and everything) but as soon as i turn the key off and push either (1) or (2) it works perfectly.. i dont know. try it

 

on my 92 300 the memory function only works when I unlock the door with the key and press the memory button,it wont work again untill I lock the door and unlock it again, weird.