HELP ME PLEASE w/2003 Dodge Neon

Recently I was re ended on the drivers side. Due to the accident my check engine light came on. The shop that 'fixed' my check engine light said the car was in limp mode...meaning it stays in 2nd gear to save the transmission and not cause it anymore damage. He cleared the light, drove it 2 miles and gave it back to me....On my drive home the check engine light was back on. The codes I received from the free diagnostic test at Autozone came up with P0700 Transmission Control System Malfunction
P0731Gear 1 Incorrect ratio
P0720Output Speed Sensor Circuit Malfunction
Can anyone tell me what is wrong with my car and if it is a result of this accident??? PLEASE I am getting the run around from the insurance companies and my dealership.

Thanks!!!

Welcome to AF!
Well if the guy hit you hard enough, it means that he made your transmission go out of shape. I don't think the accident caused it do.:banghead:

Your Output Speed Sensor is bad or the connector isn't on correctly...it needs to be replaced. That could have resulted from the accident if the connector isn't on there right, but the accident wouldn't have caused the sensor to go bad.

I can't believe the shop just cleared the light and gave it back to you w/o scanning the codes. I'd find another shop from now on.

*edit*The sensor is $21.99 from Autozone and Part #SU1034