Most difficult RX330 problem
Lexus Champion
Joined: Apr 2019
Posts: 11,197
Likes: 1,582
From: FL
The ECU-B fuse supplies "battery power" to the Body ECU and a few other things posted above- this is battery power(always hot) for when keys are out of ignition.
The Body ECU has more than one power wire but items like the "Door Control Receiver" mentioned above do not.
This is why you lost some features like the door locks and maybe other feautures that require the body ecu and other components powered by this fuse to be powered when keys are out of ignition.
Lexus Champion
Joined: Apr 2019
Posts: 11,197
Likes: 1,582
From: FL
Power Back Door ECU gets "battery power" from the ECU-B fuse too and you say it's wet back there?
And also supplies battery power to Moonroof Ecu" located at M12.
Last edited by Margate330; Dec 3, 2020 at 11:33 AM.
Thread Starter
Driver
Joined: Jun 2020
Posts: 77
Likes: 8
From: MD
Awesome info!! Im onto this i think. How do I access the power back door ECU? My power back door does not work and never did so I feel like I may be getting close.
ALSO.-- I read another post which said the right rear door control often is the culprit and when replaced it often stops the ECU-B from the parasitic draw.
I took the right rear door panel off but cant find the "door control" unit. Can you help me find these and learn how to access these two control units? 1- right rear door control unit, 2- power back gate control unit.
I want to check them both because now its getting to be a bother not having power door locks and having to reset clock every time I power up the car.
thank you!!!
ALSO.-- I read another post which said the right rear door control often is the culprit and when replaced it often stops the ECU-B from the parasitic draw.
I took the right rear door panel off but cant find the "door control" unit. Can you help me find these and learn how to access these two control units? 1- right rear door control unit, 2- power back gate control unit.
I want to check them both because now its getting to be a bother not having power door locks and having to reset clock every time I power up the car.
thank you!!!
Lexus Champion
Joined: Apr 2019
Posts: 11,197
Likes: 1,582
From: FL
Was just guessing it coud also be running down the front driver door pillar(wireless door lock receiver) or rear driver side trunk pillar(power back door ecu).
I've had the pillar cover off on passenger side trunk area but not on driver side where the pic above shows the location of the back door ecu- hopefully someone knows easy way.
PS- there are many modules involved in the fuse in question, if it was my car I would hit the ones that have only one power wire to ECU-B first and also the power back door ecu since it never worked and any other module that is malfunctioning before tearing everything out of the car and unplugging every module that connects to this circuit. lol
Last edited by Margate330; Dec 10, 2020 at 01:19 PM.
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AlanPauler
RX - 1st Gen (1999-2003)
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Oct 24, 2020 12:04 PM
