P0600 SERIAL COMMUNICATION LINK MALFUNCTION
P0720 OUTPUT SPEED SENSOR CKT MALFUNCTION

now my car doesnt shift hard and my speedometer works so does that mean that my sensor is good and the problem might be somewhere else i had some work on my transmission awhile back im thinking maybe they forgot to connect something i dont know.. ANY help would be greatly appreciated thank you

 

Just look around to see if anything is disconnected. I know on the manual transmission there are 2 jacks that need to be plugged in, I'm not sure how many with autos.

 

i dont know much about cars but i read some of the symptoms from a bad speed sensor and my car doesnt have any of them. gettin pointed in the right direction is appreciated where are those jacks located and what about that p0600 code are they related does one conced with the other?

 

P0720 (Revolution Sensor) is your main problem and needs to get addressed. Check to see if harness is disconnected but if not, you have to replace the sensor. Not sure how much that cost since I never heard of anyone replacing that sensor.