Diesel Data: Automotive Repair

Principles Of Operation




Parking Aid

Principles of Operation

The parking aid system detects objects behind the vehicle when the vehicle is in REVERSE (R) gear. 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 area around the rear of the vehicle.

The sensors can detect objects approximately 152 cm (60 in) to the rear of the vehicle and 50 cm (20 in) 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 system is 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 cannot be disabled by the operator.

The parking aid system is disabled if a fault is detected in any of the 4 sensors, the parking aid speaker or the PAM. The PAM is on the ISO 9141 network and can be diagnosed with a scan tool.