Gear Shift Problem Stuck in Neutral

OK, I read a couple posts on Gear Shift switching back to neutral. Here is my situation.
Got in the car to return some movies and realized I left them on the table. Went back to the house, and right before I turned into the driveway, noticed a metal coffee cup had come out of the holder and the edge was up under the accelerator. I had been applying my brakes to slow for the turn into the driveway, then when I went to accelerate, nothing, then noticed the cup.
Removed the cup and stepped on the gas to go into the driveway. Nothing. Turned the car off, then back on and tried to put into drive, goes a tiny bit then slips back into neutral. Tried it in reverse, same thing, pops back into neutral.
I can hold the shift lever in position and the car moves. It's in the driveway now and will get towed to the Toyota dealer tomorrow. Obviously a problem with the shifter as a result of the "coffee cup" under the edge of the accelerator. And yes, I know it's dangerous, hubby used the car last on his visit home this weekend and apparently the coffee cup either got put down on the floorboard or was knocked out. I had no idea, and I bring it in the home when I'm done.....anyway.
So, hubby is out of work and money is tight. I will have to have the Toyota dealer fix this, but I don't want to get taken to the cleaners. Anyone here have any idea if the most likely cause was the spring talked about in other posts breaking, or a switch sticking or what. Seems like something got knocked or shifted out of adjustment. Does the accelerator have some type of cut off switch if something gets lodged under it?
Any info is appreciated as to what may be wrong and how much I should be prepared for?

BTW 2008 Prius, 76,000 miles, had the transaxle fluid changed at 67,000. Everything has been working fine till this.

 

Oh yeah, forgot to mention it is HOT today. I saw that was a factor in the other reports.

So, least possible thing wrong? Any info is appreciated as to what may be wrong and how much I should be prepared for?

Also, will it hurt to hold the lever in "D" and drive it vs. having it towed?

 

Update: Went out this morning expecting to have to hold the shift lever in "D" to drive to the dealer. The car is shifting fine. Dealer couldn't take it till Thursday so it is back home with me.

After reading other posts, I'm thinking this could be heat related - either warping the plastic cover on the gear shifter unit, as you say heat damage to one of the Hall Effect switches, in the shifter assembly etc.

But I'm going to post the symptoms I now recollect I've been having over the last 6 months, in case anyone else is having the same problems. They may be an indicator of the same problem I am having and the start of gear shifter failure - might be helpful to know they may have a shifter going out.

Over the last 6 months:

1. On occasion, the shifter hasn't "taken" in "D". I've had to repeat the shift sequence when starting up to shift to "D" once or twice and it finally kicks in.

2. On at least two, if not three occasions on the freeway, I've discovered the shift in gear "B" when I clearly know I put it in "D" starting out. And no, I did NOT bump the shift lever. I put it in "D" to drive, then discovered it in "B", say an hour later. I have no idea how long it was in "B" during that hour.......

3. This situation last night with the shifter reverting back to neutral when attempting to put it in either "D" or "R". The car would drive if I held the shifter down in "D".

Thanks Tom for your reply. And Patrick on the other thread I posted on Prius Chat is a great resource, thank you to everyone who contributes.

 

Here is the update on my gear shifter problem. Brought it to the dealer for my appointment this morning. Of course I noticed that my left front headlight had gone out (car is 2008), so of course that is $75. Guess I should feel lucky my car doesn't have the expensive HID lights.

Back to the shifter, the service advisor just called and the shifter is bad. I asked him what was wrong and he tells me they found a "sticky" substance in/on it. I asked how that was possible as it was a sealed unit. He said it's not completely sealed and something got spilled on/near it. I said HOW could something be spilled on or near it if it is mounted on the dashboard. I have never had liquid or any kind on or near the dashboard. I don't open sodas, etc. in the car where some stray spray could magically just go inside the shifter opening without going anywhere else, hahaha. So no way anything sticky came from me.

He said, they've seen it before and that is what it is: sticky substance. So, that leaves two possible options:

1. It's something that Toyota failed to clean off in manufacture.

2. The VERY, VERY remote chance that when the car was at a carwash in all of two times in two years, they used spray cleaner to clean the dash and somehow sprayed it into the gearshift opening. Guess this COULD be possible, but I think highly unlikely.

Cost to repair $699. for the shifter, plus $75. added bonus of the headlight.

Hope the headlight going out was just normal wear and not an indication of a "battery" issue like poster above his having.

So, just thought I would post so everyone knows about this sticky substance getting on the shifter and causing failure. Be really, really careful not to get anything near that shifter opening.

I have asked for the old part to be returned to me so I can inspect it. I want to see the "sticky" substance firsthand. Any of you experienced members want a look at it?

 

No, there was no real difficulty shifting it - sometimes it wouldn't "take" the first time and I would have to repeat the process, but not very often. I have a call into the service advisor as I want to ask a few more questions and make sure they know I want the old part.

They didn't have the shifter in stock so had to order it. I won't have my car back till tomorrow.

I know the DIY was a better option, if I had someone to do it that would be great. But I don't. i'm going to ask the Service Advisor how much was part and how much was labor.

AND more about the sticky substance......