The C-Max Mk I was the first product to use the Ford C1 platform, also used by the Ford Focus Mk II and the compact MPV Premacy/Mazda5. Its internal code name is C214.

Vehicles can be based on a resistive or CAN protocol. The easiest way to confirm is to remove the factory radio and check if the harness has a 12v ignition feed included.

Vehicles with an ignition feed are based on the resistive protocol and vehicles without an ignition feed are based on the CANbus protocol.