When I start the car, the rear windshield wiper comes on one time .

I downloaded the owners manual and on Page 141 it shows that 'Off' on the rear wiper is if you use the washer fluid it wipes one time then automatically returns back to off. I can't see any reason it would do what you describe without you using the washer fluid http://www.toyota.com/t3Portal/document/om/OM35852U/pdf/1-5.pdf

Hi Mark, I am going to download the pdf you've attached and check it out. Maybe it should be in another position. It's never done that before when starting up so, I'm not sure. Thank you so much for your help!

My 2006 just started this same issue. I almost never use my rear wiper so I’m lost as well. It’s wierd though.... it doesn’t happen every time. Bryan

My 2007 4 runner just started with the same issue. Whenever I start my car, the rear windshield wiper goes on just once.

Test your battery, this is a common issue with 4Runner owners when the battery is getting weak you will get the one rear swipe on startup. Fixed mine as well...

This just happened to my 2006 4 runner. Weak battery. Don't know if it's a failsafe before the battery runs down to far that you can't start the car or not. But it does get your attention in the rearview mirror

Im going to change out the battery and get back. Sounds reasonable as I lost a coil pack and the traction control and other lights light up. Replaced the coil bad coil pack and all was perfect again.

The rear wiper on my 2007 Toyota 4 runner comes on when the engine is off and the doors are locked. Can’t stop it until you start the car. The battery and alternator have both checked out good. Also my rear hatch will not open sometimes. What should I check?

about the rear wiper issue..mind is starting to sweep one,the first time my 2009 4Runner is started..checked the battery is was down about 65-70 per cent ..put a trickle charge on it for a couple hours..now it doesn't come on.