my 2007 chevy 1500 is not shifting into high gear and wont shift into pass gear on 2007 Chevrolet Silverado 1500

i use to have to rev the motor a litt le to get it to shift and it would take a sec and pop in 1st from a stop now i have 1st and 2nd strong dut it wont go into over drive or down shift into paassing gear

by in Pasadena, TX on February 10, 2013
2 answers 2 comments
ANSWER by on February 10, 2013
maybe you are having transmission issues
COMMENT by on February 11, 2013
maybe you should have a scan test
COMMENT by on February 11, 2013
maybe you should have a scan test
ANSWER by on February 11, 2013
This transmission has internal mode switching logic. It is fully electronic, there are solenoids that control shifting. The vehicle needs scanning for problem codes and the transmission pan removed for inspection for possible mechancial damage.