JUST BASICALLY CAME FROM MY CERTIFIED MECHANIC FRIEND.

he figured out that somewhere at the fuse box area one of the culprits is that there was less ground connection at this certain wire, thus all power no ground.. and HE HAS THIS DIAGRAM OF THE ELECTRICAL/ELECTRONICS THINGY AND SUGGESTED TO REPLACE THE ECU..
now how much?? I'm gonna research n order hopefully not expensive..

THANKS EVERYONE FOR THE REPLY.

Disclaimers: ITS MY OWN OPINION AND MADE UP NUMBERS

 

Please let us know the ultimate solution once resolved. I thought about a ground issue that would be common to all these gremlins, but an electronic control unit seemed a more likely suspect (or a ground to an ECU). When you said your mechanic friend suggested replacing the "ECU," is he speaking of one of the many general electronic control units, or the Engine Control Unit? If he is speaking of a non-engine control unit, then which one?

 

yes, I will inform you guys of the development. as of now I'm waiting from FS1inc.com to give me the price. (I've given them my info n the VIN).

I have pics but apple iPhone's file is .heic. --> any suggestions so I can upload files here?...

anyway, in text description, the ecu we're talking about is the one by the radiator, near the left headlight, kinda triangle shaped with 3 10mm bolts... that u have to remove negative battery terminal before opening... just in case.

@ FS1inc.com its SKU CFP-11348

This Engine Computer also referred to as an Engine Control Module (ECM), Engine Control Unit (ECU) & Powertrain Control Module (PCM) is a guaranteed replacement for all 2003 Lexus SC430 PCM models with a 4.3L engine size.

Disclaimers: ITS MY OWN OPINION AND MADE UP NUMBERS

 

just to clarify / update my list way above the conversation (problem, price of parts, and price for labor).

my friend diagnosed what is common to all of the problems, and also would like to fix the aircon first(its summer).

simple technical description of what he did was manually tried to turn on a/c by fiddling with a wire..(might be thermostat), anyway it blew cold air.
he said the original ambient temperature sensor (and the new one I bought), was working fine there is electricity of 1.266 OH / OM -- forgot the term.

there is "signal" but it cant "send" -- I forgot what he said...



based on his wiring schematics it suggested to replace ECM.

.... just got email from FS1inc.com part is $299.99

Disclaimers: ITS MY OWN OPINION AND MADE UP NUMBERS

 

If the price you get for the new ECM/ECU/PCM is astronomical, you might want to look into having your OEM module repaired or refurbished. The common cause of failure is blown capacitors. Companies specialize in the replacement of the capacitors at a fraction of the cost to buy a new module. Good luck and keep us posted!

 

I SHOULD ALSO SAY IN EVERY WRITING I DID

Disclaimers: ITS MY OWN OPINION AND MADE UP NUMBERS

 

My disclaimer regarding my "opinions" should go without saying, but I had to put it in writing after multiple assaults. Some CL members have gotten very upset with me for stating opinions that differ from their own! I don't know about you, but I joined because I wanted to hear other's opinions.

The good news...I haven't been assaulted since using my disclaimer!

 

just got back from vacation, thus late update.

I finally got the ecu for the sc. installed it and everything works.