Two problems related to automatic transmission have been reported for the 2010 Mercury Mariner. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2010 Mercury Mariner based on all problems reported for the 2010 Mariner.
I was driving when it felt like the vehicle was reving in park then the "wrench" icon appeared on my dash. I went a couple blocks & my vehicle felt like it wasn't shifting automatically as it should. I pulled over & turned it off. It started right back up with no lights on, I went half a block & stopped at a stop sign but while stopped the engine reved up. I was worried I was going to be in an accident. Then the "wrench" light came back on, since I was close to home I figured I'd just try to get home. About another block, the check engine light came on & was making strange noises. I kept my vehicle at about 5-10 mph & got it home. My car was very jerky.
2010 Mercury Mariner. Consumer writes in regards to vehicle hesitation intermittently at various speeds. The consumer stated she began noticing the problem in 2011, after a 2010 update of the transmission software in a factory recall. In addition to the hesitation when trying to accelerate, there were also a few instances where the cruise control seemed to either surge or back down, as if it didn't know quite how to respond, usually, but not always, when on a slight incline. The consumer stated on one occasion, when the vehicle was in park, with the motor idling, she was unable to get the vehicle to go into to gear on the first attempt, when it did shift, it shifted very hard and noisily into gear on the 2nd attempt. Also, the vehicle would shift rough in lower gears, typically from as top or accelerating after slowing to almost a stop. The consumer went to another dealer, after the dealer where she originally purchased the vehicle from, failed to address the problems she experiencing. The second dealer informed her, the transmission valve body was damaged even before the recall came out in 2012. The part was replaced. However, the consumer experienced a hesitation in January 2013. The consumer stated after reading about an investigation of Ford vehicle, which included her model year, she was concerned about the throttle body, which had not been replaced.