toyota sienna 2004 unlock problem

Hi all, I'm having the following problem with my Sienna. A while ago, I started having trouble with the remote unlock in my 2004 Sienna.

Initially I thought it was an issue with the remote starter (so I started [url=https://www.the12volt.com/installbay/forum_posts.asp?tid=127238&KW=sienna+2004+lock]this thread[/url]).

But today I spent a while with a multimeter and I found that the issue seems to be unrelated to the remote starter.

Thing is that the unlock wire appears to be grounded all the time. It looks to me that there is a shorted wire somewhere, as this would explain both the fact that the unlock wire is grounded, and that the problem started happening once in a while until now that it basically happens all the time.

Now, I have no idea where/how to search for the shorted wire. If it is any help, the unlocking from the door switches works perfectly. It's only the unlocking coming from the remote control that doesn't work (I think that the wire that the starter uses is the one from the factory remote).

If connected correctly, your remote starter uses the lock/unlock wires that come from the drivers key cylinder. Try turning the key in the door and listen. You should hear the power locks move the drivers first, then the others on a second turn.Mike M2

Tech Manager

CS Dealer Services

This is probably a lock processor control glitch. Place a 1N4004 diode in line from your R/S unlock wire band towards the R/S. Do the same for the lock wire although it's not affected right now. This might cure the problem.

Mike M2 wrote: If connected correctly, your remote starter uses the lock/unlock wires that come from the drivers key cylinder. Try turning the key in the door and listen. You should hear the power locks move the drivers first, then the others on a second turn.

The key and the switches work perfectly. It's only the remote that doesn't open the doors. When I click the remote I hear the relay inside the R/S work, too.

howie ll wrote: This is probably a lock processor control glitch. Place a 1N4004 diode in line from your R/S unlock wire band towards the R/S. Do the same for the lock wire although it's not affected right now. This might cure the problem.

Thanks, I will give it a try.

I still haven't tried the diodes, but I solved the problem by cutting the wire that goes into the wireless receiver (which is where the R/S is hooked).

I see. Simply put, if the lock outputs don't work the unit is bad. Try disconnecting them right at the unit and check there to see if they work...Mike M2

Tech Manager

CS Dealer Services

Mike M2 wrote: I see. Simply put, if the lock outputs don't work the unit is bad. Try disconnecting them right at the unit and check there to see if they work...

That was my idea. But I really couldn't figure out the cable mess behind the dash. It looks like it first goes from the receiver to the ECU and from there it crosses the whole dash again towards the pillar. I ended up cutting the cable precisely because I didn't have the time nor energy to keep removing things in the dash. And I couldn't find a "door wiring" diagram for my van either.