Hello and welcome to Just answer.com, Super mechanic here. Please DON’T hit accept until you are completely satisfied with the answer. About your vehicle.
That is more than likely just some dirty trans fluid. The auto trans does use Dexron lll in fact.
CHANGING TRANSMISSION FLUID There is no need to change the transmission fluid unless the transmission is used under one or more of the following heavy duty conditions.
If the vehicle is used under these conditions, change the fluid every 20,000 miles (32,000 km.)
NOTE: Add transmission fluid until it flows out over the overfill screw opening.
NOTE: Be sure that transmission fluid temperature is below 30°C (86°F).