Torque Converter Clutch
A feature designed to improve fuel economy has been included in the automatic transmission on your vehicle.
A clutch within the torque converter engages automatically at calibrated speeds. This may result in a slightly different feeling or response during normal operation in the upper gears. When the vehicle speed drops or during some accelerations, the clutch automatically disengages.
NOTE:
The torque converter clutch will not engage
until the transmission fluid and engine coolant are warm
[usually after 1 to 3 miles (1.6 to 4.8 km) of driving].
Because the engine speed is higher when the torque converter clutch is not engaged, it may seem as if the transmission is not shifting into Overdrive when cold.
This is normal. Shifting between the DRIVE and 3 ranges, when the transmission is sufficiently warm, will demonstrate that the transmission is able to shift into and out of Overdrive.
See also:
Prepare A List
Make a written list of your vehicle’s problems or the
specific work you want done. If you’ve had an accident
or work done that is not on your maintenance log, let the
service advisor know. ...
Emissions Inspection And Maintenance Programs
In some localities, it may be a legal requirement to pass
an inspection of your vehicle’s emissions control system.
Failure to pass could prevent vehicle registration.
For states that require ...
Onboard Diagnostic System — OBD II
Your vehicle is equipped with a sophisticated onboard
diagnostic system called OBD II. This system monitors
the performance of the emissions, engine, and automatic
transmission control systems. ...