Wondering if anyone can help me out.

I recently tried to use my fob to lock/unlock my doors, but it didn't work... I then later noticed that my interior lights/dome/door, would stop working shortly after I turned the key off, same with garage door opener.

So now after I turn the key to the off position, exactly 14 seconds later, the interior/dome/door lights, garage door opener, and the locks/alarm from the fob all cut off and stop working. Put the key back in and turn to on position and everything back to working normally. Key fob is fine, changed the battery, I can turn car off and close the door and have 14 seconds to lock with key fob but when I come back it won't work and have to use key to open driver door, locks wont work until I put key in and turn on. Somehow 14 seconds after I switch to off position they stop working.

I do have a hunch that this has something to do with a large bit of rain that fell as it seems to have started after that rain. Also sometimes during a heavy rain I will get water leaking in from the top roof middle front by where the offroad controls/dial, garage opener, lights are ... I have had drips from there for years but no issues. But this last time it was a huge rain storm, had had a small bit of water on drivers side floor.

Any thoughts on what the problem is or how to troubleshoot. Other than that everything else is running fine.

Thanks, Bill

I would start with fixing the water leak...

Then you can address all of the electronics that have been damaged due to that water leak you let continue for years.

Don't treat the symptom, treat the cause.

Thanks that was helpful

Water leak could be due to clogged sunroof drains. As I remember from previous threads the drain lines run from the roof down to the driver and passenger sides foot well in front and down by the rear doors in back.

If you are asking how to stop the leak there are several threads on the most likely causes. I would start with; 1. Sunroof drains, 2. Roof Rail seals.

No I am not asking how to fix the leak. I am asking how to fix the electrical problem that I described.

once its turned off the power should cut off to all electronics. I have never timed it but yes it cuts off as designed. As for the key FOB replace the battery if not working.

The problem is with a damaged MPX Body computer. I was able to figure it out based on a thread in a different forum. You can see the brown spot in the bottom left corner. Car still drives fine just can't use the key fob 10-15 seconds after I turn it off. Problem is I can't find a replacement part, it is listed as 89221-35112. I find many similar ones but not one that is the right part. Anyone know were to find the MPX body computer for a 2013 4Runner Trail?

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I am having a similar issue. Ive tried everything to fix it but have not opened the MPX body computer. Did you replace this? Did it fix the issue?

Since the OP hadn't replaced the computer, he/she doesn't know (or didn't report) that the issue was fixed. I'd do my own troubleshooting if it were me. I'd start checking the drains and look for signs of leaks and fix that first. If water caused the board failure, then a new board will fail eventually if the leaks are not fixed.

Yes I can report that I was able to fix it by replacing the mpx body computer. It is a small computer box by the fuses by the front drivers side feet. It's not too hard to replace, there are some good youtube videos on all the stuff you have to take apart to get to it. I tried taking it out and cleaning it but that didn't work, seemed like one of the chips was blown. Hardest part was finding the right replacement part. A new one from Toyota was going to be insanely expensive so I waited and waited and watched for a salvage one to come up. It was pretty hard to find the correct part numbers, I guess the numbers changed and the different boxes work or don't work based on what year/trim/features you have. Best bet is to look for a salvaged one of the same year/trim... I picked one up for like $100. It was likely something leaf/stick, bug. who knows that probably clogged the drain hole to the sun roof leading to some water ripping down the door pillar into the MPX computer. But changing it out seems to work.... but curiously I now have a different problem. When I open the back right door, the back passenger dome light doesn't come on... if I open any other door, the back passenger dome light does come on... not sure if it is related to the new computer or not... haven't really tried to troubleshoot it yet?

I had the same issue where I was getting water in from the sunglass compartment. I never thought to connect to two issues. I have since unclogged the drain spouts. I have looked at everything and spent way too much time looking into how to fix. I was trying to avoid replacing the body module because I saw the price of the new module and was trying to avoid it. I opened it up yesterday and didn't see any stand-out issues like your photos but I am sure that doesn't mean anything.

Your dome light issue might be related to the door jamb switch being old? I just swapped one out. Pretty cheap and really easy to replace.

Toyota 4Runner Switch, Courtesy Lamp
Part Number: 84231-60070

Anyway, I greatly appreciate the response. This gave me the final push to just replace the damn body control module.

Last questions... Did you have to get this new MPX Body computer programmed?

So, the question is, is the new MPX computer responsible for the rear door dome light problem? You could swap the old MPX computer back in and see if the dome light works; or troubleshoot it as a new problem. Seems like you know what you are doing with swapping things (disconnect battery to prevent damaging anything, etc.) so I'd try that first.

I purchased a used MPX from ebay and installed it this past Sunday. It fixed the issue with the 10 second deadline of locking the doors but I wasn't able to program the key faub. I figured it was due to not having the MPX flashed or reprogrammed yet. I brought it to Toyota dealership first thing the next morning. They kept the car for 2 and 1/2 days telling me they couldn't get it to work. They of course quoted me $1,600 to install a new one which I could do myself.

So frustrating because I don't know if they were just dragging me along and were always going to try and force a new MPX install or if it was actually faulty. My gut tells me it was the first.

I am literally in "no-mans land" because I don't know if I'll get the same issues if I try somewhere else. Or if I should just cut bait and return it.