Zone 1

WARNING: This page is about a different car, the 2003 GMC Sierra, 2003 GMC Cab & Chassis Sierra, 2003 Chevrolet Silverado, and 2003 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.

Turn steering wheel to place vehicle wheels in straight-ahead position. Turn ignition off and remove key. Remove SIR fuse (15-amp) from underhood fuse block.
Remove Connector Position Assurance (CPA) clips from driver-side and passenger-side Electronic Frontal Sensors (EFS), also known as front end discriminating sensors. Disconnect both EFS connectors.

Fig 1: Identifying Electronic Frontal Sensor (EFS)

Courtesy of GENERAL MOTORS CORP.