'08 GS350 RWD...I'm having weird problems.
I replaced my battery which lead to replacing the matrix. Now
​​VSC check coming on, steering angle sensor, key fob won't unlock the door or trunk but the car starts and runs perfect. The telescoping steering doesn't retract and security light goes on for 10 seconds then off. Assuming Security isn't arming. Noticed I can't unlock the door locks once I'm in opening manually. Even when I turn off the car I'm not able to pop the trunk or gas cap. Like there is no power until I push the start button. I've reprogram keyfobs and did sensor test and the car recognizes the keys but not after I power the car off.
Could this be a bad ecu? Maybe a relay???
Running techstream shows ABS/VSC/TRACK code C1231 , AFS B1424 and steering angle sensor. (Tried resetting steering angle sensor per instruction on this forum both manual and through techstream. No luck)
I've been through all the reset threads with these problems with no luck. Trying everything for the past 2 weeks. Pulled the ecu next to the matrix and looked at it. Didn't see anything burnt up or weird dark spots. No blown fuses
Any help would be great before I purchase another main ecu. I've searched the heck out of this forum for answers and haven't found a solution. The car starts/runs and drives perfect. No traction control but...
The weirdest thing is no power anything after I shut the car off.
THANKS EVERYONE!

 

Sounds like its possibly bad battery terminals, have you ever replaced them with oem? If not you can use ones out of a toyota yaris, as they are the same and cheaper.

 

I have complete power as soon as I hit the start button. Power doors work, trunk opens. Everything works as it should.
I did notice my mpg reset Everytime...
​​​​​ like what happens when you fill the tank. I've cleaned my gas cap and made sure it was sealed many times. Weird the mpg reset Everytime I start the car. It used to only reset when I filled the tank

 

Sounds like youre getting poor voltage, you can have intercepted voltage that will still start the car, and power things up. But when you get the voltage drop and the battery connection is lost, it will run off the alternators voltage. Which is why I suggested first start with new terminals. Or atleast take them apart, inspect them for any broken tabs clean them with sand paper, remove the 12 or 14mm nut thats on top and clean those terminals aswell. If you still get poor I would inspect the wires from the battery to other points of contact like to the starter, make sure your ground cables are tight and secure etc.

Also I believe you can run techstream and do a voltage check while driving the car. If you do see significant drops then I would check things like the voltage to the alternator while the car is running it should put out around 13.5 volts

 

Voltage are good with car running 13.4v and car off at 12.4v.
Running through Techstream I can see the updated voltages. Checked Voltages at multiple fuse boxes and main ecu and had 12.3v and good a good grounds at multiple points. In techstream I did go through every tab today and found that the "Gateway Can" was not responding or available... is this normal?


plus I couldn't find a tab forsecurity. Reading on another thread saying there theft deterrent ecu was bad and replacing that solved there problems. They had very similar problems. I could find anything about the theft deterrent ecu on techstream or how communicate with it too see if that's a culprit.

 

These ecu's rarely go out! Only the 2006 year has common ecu problems.

Did you try redoing the battery terminals and cleaning them? What about the battery in the key fob, have you replaced it recently?

 

Oh yeah everything everything is nice and shiny. I put a new battery in the keyfob. I've run the test on techstream where it test's the key all around the car. No problems, the car recognizes the key at all 4 corners. The problem is deeper into the car. As long as acc is on.

When you power the car down from(car not actually running). The vehicle cuts all power to everything. Power door locks don't work, can't pop the trunk or gas cap.
Example: if you pop the trunk when the car is on(not running). The trunk will open and soft close no problem. But if you open the trunk then shut the power off after popping the trunk, you cannot close the trunk, it will not soft close or even allow you to slam it closed. You then have to power the car back on(not running) to get the trunk to close properly. These are all test performed without the car running.
Somewhere the voltages are being but off after the can is turned off. Totally baffled. Check every single fuse again last night and everything is perfect.

 

Researching this morning.Looking... at the schematics from the Gateway Ecu. Everything from the theft deterrent ecu down the line is not working. So the question now is to find the Theft Deterrent ecu and probe from there. Anybody have an idea where it is?
Thanks 😁

 

https://workshop-manuals.com/lexus/g...ion/locations/

 

I crossed looked up all the numbers on what the gateway ecu should be from the diagrams. Maybe I pulled the wrong part. It did look ok. Nothing burnt up (not that proves that is good) the part number that comes up 82730-30a52 is a Fuse Junction Block Relay Box. maybe I missed something.
Anybody know if this is part of the gateway ecu?
As for pulling the immobilizer ECU. Holly cow that's not gonna be easy and looks like a complete dash removal. Anybody got suggestions?

Think I've narrowed it down to the 2 things it can possibly be??? Should I replaced the gateway ecu or the immobilizer ecu?
All opinions are welcome 😁
This is what I pulled out tonight to check 👇

 

There was a member that had an immobilizer go bad on him, the dealer quoted him a dash removal. Why not try taking it to the dealer and pay for 1 hours worth of diagnostics.

 

I'm nearly at that point. I read on the LS forums a guy with similar problems said the immobilizer cured everything. I sent him a message for some insight. A new gateway can ecu is $100+- on eBay.... Might take gamble on that since it's super easy to replace. Checked last night and Techstream still can't connect to it.
Having the scary feeling a dash removal is coming. 😭

 

I would avoid throwing parts at it hoping to get lucky, pay someone who is good at diagnostics