Rich good luck definitely let us know how it turns out.

I thought i'd do a quick update, but windows all work properly still. My problem was definitely the mpx box.

Ryan

 

i had exact same symptoms as author. as a fyi.... the part mentioned is for a g3 gs300 - gs400. same part work in g2 gs300 and gs400 models as well.

excellent article! i found a used one on ebay. around $100.

thank you for your post. nicely done sir.
rp

 

Good thread, helps chase down the uncommon ailment.

In my case, it ended up being a plain old bad window motor. Just like the countless hundreds he'd replaced before, said my service advisor (a former Lexus tech for 10 years).

#oldusefulthread

 

Oh and you should hear what the procedure is to dial in the automatic up/down window function is on these older cars after swapping in a new window motor. It's like putting together a Swiss watch. To my amusement, they gave it to the new guy to sort out.

To his solid credit, he got it on the first try. Nice.

 

Does all the MPX's are swappable or its like Front Driver is compatible with Front Passenger and Rear ones only with other Rear MPX

 

Did the mpx fixed your problem? Mine is doing the same thing.

 

i have mpxs if anyone needs for good prices.

 

I was having the same issues on the front passenger window. It went from sporadic up and down to not going up or down at all in two weeks. After reading this thread, I swapped in the driver's side MPX and it went up right away! Thanks for the thread!

 

To followup to my post a few weeks ago, I replaced the passenger side mpx with a used mpx. The passeneger window goes up and down just find using the passenger switch, but from the drivers switch, 1) I can't move the passenger side up or down and 2) the other three windows will only move 2 inches at a time. The drivers side switch was working fine prior to replacing the passenger mpx.

Is there a reset that needs to be done in order to synchronize the mpxs together?

Thanks!

 

Thanks for sharing! I was definitely wondering what might be the problem to this (as it's a slightly common problem with Lexus' in general.

 

My apologies if I'm resurrecting this thread from the dead but it's better than starting a new thread with the same topic I guess.

Anyway, as with everyone else, the front passenger window has been acting up until it finally would only go down and now it won't come up at all.

When I try to use the window switch, either on the passenger door or on the drivers side door I can hear a little clicking but nothing happens to the window.

I've swapped over the MPX module from the drivers side to the passengers side but still nothing I at least wanted to get the window up somehow. Also, now when I try either of the switches, there is no clicking at all.

Putting the drivers side MPX back in it's normal spot allows the drivers side to operate just fine again but the passenger side is still dead.

Is there any way to manually raise the passenger side window until I can source a replacement MPX unit?

 

you'd have to connect some power to the motor. measure how much voltage before hand though. i doubt its a 5v motor. but check to make sure

 

Cheers for that.

While driving later that day I was playing with the drivers side switch and somehow managed to get the window back up. However, I'll keep in mind the manual method you mention if it does happen again.

 

Hello,

I'll be switching the MPX from the passenger to driver side tomorrow to see if it fixes my issue.

I will report results.

Thanks guys!

 

Thanks for resurrecting this thread. I've been fighting this on my 2001 RX300 for 10 years! I know it's based on Camry body components so I'm hoping this applies too. I've performed the resets to no avail. Began on the driver's side and has now involved the passenger side too.

Did the new MPX box fix your issue based on your post from 2 weeks back?

I found this video describing how to resolder the connections on the door switches. Haven't tried it but it fixed his Mom's RX300 window issues.