To replace one of these bulbs:

1. Remove the two screws holding each of the license plate lamps.
2. Turn and pull the license plate lamp toward you through the opening.
3. Turn the bulb socket counterclockwise and pull the bulb straight out of the socket.
4. Install the new bulb.
5. Push the bulb straight into the socket and turn clockwise to reinstall.
6. Push and turn the license plate lamp away from you through the opening.
7. Reinstall the two screws holding the license plate lamp.
Back-Up Lamps (Coupe)
Replacement BulbsChevrolet Cobalt Service & Repair Manual. Description
AC-Delco Tandem Diaphragm Type
This unit utilizes a vacuum power
chamber, consisting of a front and rear shell, housing divider, front and
rear diaphragm, plate assemblies, hydraulic pushrod and a diaphragm return
spring, Fig. 1.
In normal operating mode, with
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