Steering Pad Switch Circuit: Description
WARNING: This page is about a different car, the 2007 Toyota Prius. However, it is still accessible from the selected car via links, so may be relevant.
This circuit sends an operation signal from the steering pad switch to the radio receiver.
If there is an open in the circuit, the navigation system cannot be operated using the steering pad switch. If there is a short in the circuit, the resulting condition is the same as if the switch were continuously depressed. Therefore, the navigation system cannot be operated using the steering pad switch, and the navigation system itself cannot function.