We are leaving Charlottesville, VA in a few minutes in our 2008 Prius for the 725 mile drive home. Our son has had it for three years and recently purchased his own car. I tried to drive it from the parking lot two days ago and it would jump out of gear after about 1 second in reverse. I held the shifter down in reverse and backed it out of the parking space after the battery performed a recal. It would not shift into park at all unless the power button was pushed to shut the car off. It did the same thing in forward, so I pulled it back into the parking space. The interior of the car was extremely hot. I could barely hold the steering wheel.It is a black car and the ambient temp was in the 90's. Yesterday our son came to pick us up at the hotel in it and it operated normally. We drove it back to his parking lot and left it while we did the tourist stuff today in his car. It sat in the parking lot until about 4:00 and I decided to fill it with fuel and put air in the tires for a road trip.. Once again, it would not stay in drive. I held it in drive for about 20 miles with the AC running on high. The interior cooled down considerably, but it still would not stay in drive. I left it again for about 45 minutes and tried it again when we left for dinner. It drove perfectly. I had Autozone hook the Obd reader up to it and it didn't show any codes. The voltage was checked and he said it was at 13.1v. The car will be 5 years old in September and I was suspecting the battery. There wasn't a battery for it anywhere in Charlottesville, so we will head home with the original battery. I searched the internet (and PriusChat) last night and found the same issue in a lot of Gen II and in some Gen III. The repairs for the issue were sketchy, but some had said the dealerships had changed out the shifter and repaired the problem. The 12v. battery will be changed out when I get home unless I find one on the way. Any ideas?
Almost certainly you have a failing shifter switch. This is the little shift knob that sticks out of the dash. It has a series of switches that tell the computer what gear you want, and when it gets old it stops making good contact. Holding it in place is a temporary fix. You can have it replaced by the dealer, or if you are handy, you can do it yourself. Instructions can be found on PriusChat. Tom
The ICE has nothing to do with the 12V system. When in Ready, the 12V bus is powered by a DC to DC converter, so the voltage will always be in the good range unless the 12V battery is shorted or some other issue is keeping the DC to DC converter from working. Tom
"nothing" could be a stretch. One fact I left out, the first time I started it and had the issue, the 201v. battery did a recal.
qbee42 is right that it's the shifter switch. More specifically, it's a couple pieces of thin plastic that are used to keep dust out of the shifter switch that have warped, probably due to the heat, and prevent the shifter from staying in place. I'm too new to post a direct link, but search priuschat for "How to Replace 2G Gearshift Lever", (include the quotes). The first post describes how to get access to the shift lever. nickbike has a post about 2/3 of the way down that includes a couple videos, the second of which shows the offending pieces of plastic. nickbike was able to trim his to restore functionality. I had this same problem and had to discard the plastic because it was so badly warped. As a result, part of my shifter is now exposed to dust, but it works fine again. Good luck.
It is very simple. I have replaced 6 or 7 of these. Can usually get from eBay or car-part.com for $25-$40 Remove left side A/C vent by pulling gently but firm. If you have a plastic trim tool or wrap a screw driver with a rag you can pry a little. Unscrew now expose Phillips screw and Phillips screw below dash on same panel. Pull that panel off. It is unnecessary to unplug any connectors. Now remove the panel above the steering wheel by pulling. It is just held on with tabs like the lower one. Open the CD storage compartment below the radio and gently remove the A/C vent that houses the shifter. Be careful with this one it cracks or breaks easily. You can unplug the park button or just leave it plugged and move it out of the way. There are 3 - 12mm bolts that hold the shifter in. Remove them and unplug. Plug in new one and reverse to put back together. Don't forget to plug the park button back in if you undo it.
How to Replace 2G Gearshift Lever | PriusChat Note that you can probably repair the existing gearshift lever by trimming the plastic that keeps dirt out of the mechanism.