Help! Moving backwards in drive
 

I have a beautiful 2008 4Runner with about 77,000 miles. I was leaving a store today & while the car was in drive it started rolling backwards (we were not on a hill). I shut it off and then tried again & the same thing happened. I put it in park & when I put it back in drive it was fine. The weird thing was when I would try to give it gas while it was rolling back it did nothing. I am not a car savvy girl (:redface:) at all so I was hoping you guys might have an idea of what happened. Thanks for any advice you can give me!

Was your foot on the brake??

No, my foot was not on the brake. I put it in drive and as I was going to give it gas it was rolling backwards, I kept looking to make sure it wasn't in reverse or neutral & it was definitely in drive. The gas pedal just wasn't working either, I could easily press it all the way down & just keep rolling backwards.

Has any major service been done to it? (Transmission fluid change/flush, rebuild, etc.). Are any warning lights coming/staying on?

First impression is that you don't have enough T-IV ATF fluid, and the torque converter is running dry (and the rolling backwards just so happens to be a slight rear incline). Lack of response from the gas pedal could be from a safety when the transmission detects a low fluid level.

Second, you may have the wrong type of transmission fluid (hence why I asked if you had any major service) that is possibly restricting a hydraulic line to either a band, or the reverse gear actuator or a whole host of different hydraulic problems.

Third, something is loose in the gearshift linkage, making your gauge read "D", but your transmission is actually in "N".

Fourth, the transmission is failing (extremely unlikely for a 4runner so new with very little mileage, unless it wasn't properly taken care of).