Operation CHARM: Car repair manuals for everyone.
Manuals through 2025 now available!

Our trusted friends have launched a new website named LEMON, which has newer manuals. It also contains all the CHARM manuals.

LEMON is the spiritual successor to CHARM, I recommend you try it!

Link: lemon-manuals.la or lemon-manuals.org.ua

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Remote Control Interface Unit



Remote Control Interface Unit
The remote control interface unit converts the analogue signals from the steering wheel switches into digital signals for use by the navigation computer. The remote control interface unit is installed in a bracket immediately below the navigation computer.

The radio remote switches form a resistance ladder between two wires with the resistance across wires dependent on which switch is pressed. The remote control interface unit monitors the two wires and converts their input into Instrument (I) bus protocol messages, which it outputs on a dedicated serial link to the navigation computer.