Gear shift issue

[Julio C Perez]

Hi, I've got a 2010 toyota corolla. It's been having a weird problem. When it is raining and I have to use the windshield wipers it starts to jump and goes off gear. It also happens when I make a right turn with the turn signal on, especially after it's been running for a while. The check engine light has come off in two occasions, both times while driving at about 75 mph on the highway and using the wipers when raining. The computer showed code P0500 which my mechanic said it involved a speed sensor. We changed the speed sensor, but the problem continues. Took it to the dealer to have two recalls done involving the ECM, but didn't help either. It starts jumping and accelerates as going off gear while in drive mode. My mechanic says he had never seen that. Does anyone have any idea about what it might be? Thanks