Switch, Park Assist: Operation

WARNING: This page is about a different car, the 2017 RAM 2500 HD. However, it is still accessible from the selected car via links, so may be relevant.

The status of the park assist Off switch is continually monitored by the circuitry within the instrument panel switch pod (also known as the Accessory Switch Bank Module/ASBM). The switch pod receives battery voltage at all times on a fused battery feed circuit and has a path to ground at all times through the instrument panel wire harness. The inputs to and outputs from the switch pod consist of electronic message communication with the Body Control Module (BCM) (also known as the Common Body Controller/CBC) over the single wire Local Interface Network (LIN) data bus.

Each time the park assist Off switch push button is depressed the switch pod circuitry sends an electronic park assist switch status message input to the BCM over the LIN data bus. The BCM then relays an electronic park assist switch request message to the Park Assist Module (PAM) over the Controller Area Network (CAN) data bus. The PAM responds to each park assist switch request message by toggling the status of the park assist system from enabled to disabled, or from disabled to enabled, then sends an electronic park assist system status message back to the BCM over the CAN data bus as confirmation.

The BCM responds to the system status message by sending a message to the switch pod over the LIN data bus to control the park assist Off switch Light Emitting Diode (LED) unit so that the LED is illuminated with the system disabled while the status of the ignition switch is On, and is extinguished with the system enabled or with the status of the ignition switch anything except On.

The hard wired circuits between components related to the park assist Off switch may be diagnosed using conventional diagnostic tools and procedures. Refer to the appropriate wiring information. However, conventional diagnostic methods will not prove conclusive in the diagnosis of the electronic controls and communication between modules and other devices that provide some features of the park assist system. The most reliable, efficient and accurate means to diagnose the park assist Off switch or the electronic controls and communication related to park assist switch operation requires the use of a diagnostic scan tool. Refer to the appropriate diagnostic information.