If your vehicle has power locks, it has a programmable automatic door unlock feature.
The doors can be programmed through the Driver Information Center (DIC) to automatically unlock several ways. See DIC Vehicle Personalization for more information.
Chevrolet Cobalt Service & Repair Manual. Engine Oil Pan Gasket R&R
1.
Install the engine support fixture.
2.
Remove the engine mount.
3.
Raise the engine enough to allow clearance
for the oil pan removal.
4.
Raise and support the vehicle.
...