FREE REPAIR MANUALS & LABOR GUIDES 1982-2013 Vehicles
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Principles of Operation




Parking Aid

Principles of Operation

NOTE: The liftgate must be closed for correct operation of the parking aid system.

NOTE: The Smart Junction Box (SJB) is also known as the Generic Electronic Module (GEM).

The parking aid system detects objects behind the vehicle when the vehicle is in REVERSE (R) gear is selected. The Parking Aid Module (PAM) does this by calculating the distance to an object by the use of 4 ultrasonic sensors mounted in the rear bumper. The sensors determine the distance to an object within the 170 degree semicircular azimuth area around the rear of the vehicle.

The sensors can detect objects approximately 1.8 m (5.9 ft) to the rear of the vehicle and 50 cm (1.6 ft) to the rear side of the vehicle, and 16 cm (6 in) above the ground. A variable rate warning tone is generated from a speaker attached to the PAM. The speaker increases its warning tone rate as the vehicle gets closer to an obstacle. When an object is detected within 25 cm (10 in) of the sensors, the warning tone becomes continuous.

The parking aid system is enabled when the ignition switch is in the RUN position and when the gearshift is in REVERSE (R) gear. The parking aid disabled indicator illuminates for 3 seconds when the ignition switch is turned to RUN. The system can be disabled by pressing the parking aid switch on the instrument panel. The parking aid system indicates it is disabled by illuminating the parking aid disabled indicator (in the parking aid switch). The system is always enabled when the ignition switch is turned to the RUN position, and when the vehicle is put into REVERSE (R) gear.

The parking aid system is disabled if a fault is detected in any of the 4 sensors, the parking aid speaker or the PAM. This is indicated by the parking aid disabled indicator being illuminated when the vehicle is put into REVERSE (R) gear. The PAM is on the International Organization for Standardization (ISO) 9141 network and can be diagnosed with a scan tool.