I could really use some help from the community, a mechanic, Toyota/Lexus technician possibly, anybody.

I have a 2004 Lexus RX330, and I've been having a parasitic battery draw issue, and I tracked it down to my power windows. They seem to stay on after the car is off.
I've used techstream did a full health check and shut all of my lighting options down, (IE exterior entry/exit lighting, headlight delays etc) everything that I can think of. Still power remains on hours after the car's been sitting.

I thought maybe my body control module was bad. I've also noticed a new issue that goes along with it.
When I have the window 'lock' button enabled, while driving the car. I can't roll down the windows with the master switch,(except the driver's window) BUT they can be rolled down at each individual door. It's totally bizzar. Any thoughts?

Thanks,
Sean

 

Try this test, remove/disconnect the master window door switch and see if the draw stops. I would think it's the master switch with the new issue of the window lock. Toyota did have some bad luck with master switches and it was recalled for certain year Camry's.

 

Popped out master switch and unplugged, voltage dropped by 1/2...other windows stayed active and able to be rolled down still at their doors. I got another master switch off eBay, will let ya know if that solves this weird power windows active with key off issue. Otherwise I'm thinking maybe BCM? Pull out the ol parts cannon..

 

BECU is not fun to replace, hope it's the master switch. Best of luck!

 

Thanks for all your help. Yeah, I've been thinking of all these modules talking to new BECU, Immobilizer issues VIN changes. Thanks again

 

Update: well, the new 3rd party master switch arrived today.unpkugged battery and installed. Have to say, it was the weirdest thing I have ever seen.temp gauge started going up and down, TPMS sensor light started flashing, lost all console lights for AC and vents. Windows worked for driver only. Now I know it's not a Toyota part, but for the PCB in that switch to cause all those problems makes me think heavily on a funky BECU. Gonna return this master switch and look for a used Toyota module and see if it works. Power still stayed on this unit too.

Sav

 

Crazy! lol
Did you ever figure it out- body ecu or switch?
Thinking the 3rd party switch could very easily send "inapropriate" data on the multiplex BEAN bus wire(MPX) causing all kinds if strange symptoms if not compatable with our cars aka not as advertised.

 

it's the bcm, I'm guessing it's inside the instrument panel fuse box. At lease that's what I've found out so far.gwtrigg ready to get a used on on ebay.anyone else know if the BCM us actually inside the fuse box under dash? I know the engine fuse box has a computer board on the front side of it..with a heat sink and all

Sav

 

Yes, the one onder the driver side finish panel under the steering wheel with all the fuses is the Body ECU.
The engine fuse/relay box with the heat sink is a junction box.

PS- I picked up an extra Body ECU off ebay a while ago dirt cheap for a spare and planned on opening t up to have a look but haven't got around to it yet.