does not shift out of 1st gear. no problems with reverse park or neutral.
If the transmission fluid is full and clean, could be an issue with a shift solenoid. There may be a code stored int eh computer that wouldn’t necessarily turn on the check engine light. Have any codes pulled and post them below.
How the transmission works in a 2006 Chevy Monte Carlo
The 4T65-E is a fully automatic front wheel drive electronically controlled transmission. The 4T65-E provides four forward ranges including overdrive. The PCM controls shift points by means of two shift solenoids. A vane-type oil pump supplies the oil pressure. The PCM regulates oil pressure by means of a pressure control solenoid valve.
All vehicles equipped with a 4T65-E transmission have an electronically controlled capacity clutch (ECCC) system. In the ECCC system, the pressure plate does not fully lock to the torque converter cover. It is instead, precisely controlled to maintain a small amount of slippage between the engine and the turbine, reducing driveline torsional disturbances.
You can operate the transmission in any one of the following seven modes:
| •||P — Park position prevents the vehicle from rolling either forward or backward. For safety reasons, use the parking brake in addition to the park position.|
| •||R — Reverse allows the vehicle to be operated in a rearward direction.|
| •||N — Neutral allows the engine to be started and operated while driving the vehicle. If necessary, you may select this position in order to restart the engine with the vehicle moving.|
| •||D — Overdrive is used for all normal driving conditions. Overdrive provides four gear ratios plus a converter clutch operation. Depress the accelerator in order to downshift for safe passing.|
| •||3 — Drive position is used for city traffic and hilly terrain. Drive provides three gear ranges and drive range prevents the transmission from operating in fourth gear. Depress the accelerator in order to downshift.|
| •||2 — Manual Second provides two gear ratios under most operating conditions. Manual Second provides acceleration and engine braking. Select this range at any vehicle speed, but the transmission will not downshift into Second gear until the vehicle speed drops below approximately 100 km/h (62 mph)|
| •||1 — Manual Lo provides maximum engine braking. You may also select this range at any vehicle speed, but the transmission will not downshift into First gear until the vehicle speed drops below approximately 60 km/h (37 mph).|