What does it mean?
OBD II trouble code P0810 is a generic code that is defined as “Clutch position control error”, and is set when the PCM (Powertrain Control Module) detects a fault, failure, or abnormal voltage or resistance in the clutch position sensor circuit. Note that this code apply applies to applications with manual transmissions. As the code’s definition suggests, the clutch position sensor monitors the position of the clutch pedal when the ignition is turned on.
In a fully functional system, the clutch position sensor interrupts the ignition circuit if the clutch pedal is not fully depressed, which prevents the engine from being started. This is intended as a safety measure to prevent the engine from starting until the engine is decoupled from the transmission by means of disengaging the clutch.
In practice, this measure is analogous to the safety cut-out switch that prevents a vehicle with an automatic transmission from starting unless the gear selector is in either the “P” or “N” position. The image below shows a typical clutch position sensor, such as might be found on many VW applications.