Principles of Operation

WARNING: This page is about a different car, the 2010 Lincoln MKX and 2010 Ford Edge. However, it is still accessible from the selected car via links, so may be relevant.

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

The parking aid sensors detect objects approximately 152 cm (60 in) from the rear of the vehicle, 50 cm (20 in) 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 area around the rear of the vehicle. A variable rate warning tone is generated from a parking aid speaker attached to the PAM . The parking aid 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.

A volume cutback request message is sent to the Audio Control Module (ACM) from the PAM over the Medium Speed Controller Area Network (MS-CAN) to decrease the volume of the ACM while the parking aid warning tone is sounded.

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 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 , ACM and the Instrument Cluster (IC). The following chart describes network messages used by the PAM :

NOTE: Both the 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 IC . Refer to MODULE COMMUNICATIONS NETWORK .

PARKING AID MODULE (PAM) NETWORK COMMUNICATION MESSAGES

Broadcast Message	Originating Module	Network Type	Receiving Module
Audio volume cutback request	PAM	MS-CAN	ACM
Ignition switch position	SJB	MS-CAN	PAM
Parking aid enabled command	IC	MS-CAN	PAM
Parking aid system status	PAM	MS-CAN	IC
Transmission selector (PRNDL) range	PCM	HS-CAN	IC
Transmission selector (PRNDL) range (gateway)	IC	MS-CAN	PAM
Vehicle speed	PCM	HS-CAN	IC
Vehicle speed (gateway)	IC	MS-CAN	PAM