Why won't car shift into high gear in cold weather? Interior is not warming.

Possible thermostat with a long warm up time. The blower probably needs a blower speed control module, and possible shift problem in cold weather, is the computer stays in open loop because engine temp has not reached proper temp to go into closed loop operation.

Amber, you need to have a mecanic take a look at this for you. It could be thermostat realated as for no heat AND trans shift! The blower fan resistor, if equipped, may be another possible problem for fan speeds.