Description And Operation
DESCRIPTION
The Park Assist Module (PAM) (1) for this vehicle is secured on the inboard side of the left rear quarter panel behind the interior quarter trim panel. The module is connected to the vehicle electrical system through dedicated take outs of the body wire harness.
There are three mounting tabs integral to the module housing that secure the module to the vehicle body. Two connector receptacles containing terminal pins that connect the module to the vehicle electrical system are integral to the one side of the housing. One of the receptacles is utilized in vehicles equipped with only the rear park assist system, while both receptacles are used on vehicles equipped with both the front and rear park assist systems.
The PAM cannot be adjusted or repaired and, if damaged or ineffective, it must be replaced with a new unit. The PAM software is flash programmable.
OPERATION
The PAM has the following characteristics:
- It receives power supply for its operation.
- It provides power supply to the 4 sensors.
- It receives signals from the 4 ultrasonic sensors.
- It manages the presence of a possible trailer: it is configured to deactivate the rear sensors when a trailer is present.
- It communicates and transmits data over the high-speed Controller Area Network (CAN) -CH network.
If a fixed tow hook is present, the signal "Trailer presence" informs the PAM control unit to deactivate the rear sensors if a trailer is attached to the car. The signal "Trailer presence" is sent by the Trailer Tow Module (TTM) via Controller Area Network - Internal High Speed (CAN-IHS) data bus.
To ensure the proper operation of the system when the trailer is not attached to the vehicle, the PAM control unit changes the sensor detection area range in order to take into account the space occupied by the tow hook.
Semi-automatic parking control unit PAM
The semi-automatic parking control unit PAM has the following characteristics:
- It receives power supply for its operation.
- It provides power supply to the 12 sensors.
- It receives signals from the 12 ultrasonic sensors.
- It manages the presence of a possible trailer: it is configured to deactivate the rear sensors when a trailer is present.
- It communicates and transmits data over the high speed CAN-CH network.
The microcontroller in the PAM contains the park assist system logic circuits. The PAM uses On-Board Diagnostics (OBD) and can communicate with other electronic modules in the vehicle as well as with the diagnostic scan tool using the Controller Area Network (CAN) data bus. This method of communication is also used for park assist system diagnosis and testing through the 16-way data link connector located on the driver side lower edge of the instrument panel.
The PAM provides voltage to the park assist sensors located in the bumper fascias. The PAM monitors return inputs from each of the sensors on dedicated hard wired data communication circuits. These sensor inputs allow the PAM to determine when an obstacle is in the path of the vehicle. When an obstacle is detected the sensor inputs allow the PAM logic to calculate the relative location of the obstacle, and whether the distance to that obstacle is increasing or decreasing.
Pre-programmed decision algorithms and calibrations allow the PAM to determine the appropriate park assist system outputs based upon the inputs received from the park assist sensors and electronic messages received from other modules in the vehicle over the CAN-CH data bus. When the programmed conditions are met the PAM sends electronic messages to the Instrument Panel Cluster (IPC) over the CAN data bus via the BCM to obtain the proper park assist system audible outputs and textual messages in the IPC display. The PAM also broadcasts electronic messages over the CAN data bus to enable the other electronic features of the park assist system.
The PAM continuously monitors all of the park assist system electrical circuits and components to determine the system readiness. If the PAM detects a monitored system fault, it sets a Diagnostic Trouble Code (DTC) and sends the appropriate electronic messages to the IPC over the CAN data bus via the BCM to control operation of certain park assist system audible and textual warnings.
The PAM receives battery current on a fused ignition output (run-start) circuit through a fuse in the Power Distribution Center (PDC). The PAM receives ground through a ground circuit and take out of the body wire harness connected to the body sheet metal. These connections allow the PAM to be operational whenever the status of the ignition is Start or On.