Principles of Operation

PRINCIPLES OF OPERATION

NOTE:
- The smart junction box (SJB) is also known as the generic electronic module (GEM).
- Both the medium speed controller area network (MS-CAN) and the high speed controller area network (HS-CAN) are used for intermodule communication. A gateway message is transferred from one network to another network through the instrument cluster. Refer to Information Bus (Module Communications Network).

The parking aid sensors detect objects approximately 1.6 m (5.3 ft) from the rear of the vehicle, 50 cm (1.6 ft) from the rear side of the vehicle, and 16 cm (6 in) above the ground. The parking aid module (PAM) calculates the distance to an object within the 170 degree semicircular azimuth area around the rear of the vehicle. A 750 Hz variable warning tone is generated from a parking aid speaker which is attached to the PAM. The parking aid speaker increases the warning tone rate as the vehicle gets nears 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 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 condition is indicated by the parking aid disabled warning in the message center. The PAM is on the 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 cluster (IC) or the MS-CAN. The following chart describes network messages used by the PAM:

PAM Network Communication Messages: