Pontiac 2003 Bonneville Owner's Manual page 248

Rocking Your Vehicle To Get It Out
First, turn your steering wheel left and right. That will
clear the area around your front wheels. If your vehicle
has traction control, you should turn the system off.
See Traction Control System (TCS) on page 4-9. Then
shift back and forth between REVERSE (R) and a
forward gear, spinning the wheels as little as possible.
Release the accelerator pedal while you shift, and press
lightly on the accelerator pedal when the transaxle is
in gear. By slowly spinning your wheels in the forward
and reverse directions, you will cause a rocking
motion that may free your vehicle. If that doesn't get
you out after a few tries, you may need to be towed out.
if you do need to be towed out, see "Towing Your
Vehicle" following.
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