Principles of Operation

Parking Aid

Principles of Operation

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 REVERSE (R) gear is selected. The Parking Aid Module (PAM) calculates the distance to an object by the use of 4 ultrasonic sensors mounted in the rear bumper. The PAM does this by calculating the distance to an object within the 170 degree semicircular area around the rear of the vehicle.

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 30 cm (12 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 the REVERSE (R) gear is selected. The parking aid system is disabled if a fault is detected in 1 of the 4 sensors, the parking aid speaker, or the PAM. This is indicated by a parking aid disabled warning message in the message center.

The PAM is on the Medium Speed Controller Area Network (MS-CAN) and can be diagnosed with a scan tool. The PAM communicates with the scan tool, the SJB, the Audio Control Module (ACM) and the Instrument Panel Cluster (IPC). The following chart describes network messages used by the PAM:

PAM Network Communication Messages: