[GTP Dad]

Does this happen when you hit or let off the brakes? This may be a brake problem or a CV joint issue not necessarily a problem with the transmission. To do the key dance, turn the key on and off three times on the third time leave the key on and the codes will flash on the check engine light. I suggest that you have the car scanned with a scanner since this is an OBDII computer. The scanner will provide you with the exact code not a generic one provided by the light.