Engine Running Detection

The BECM has two methods of detecting that the engine is running; tachometer pulse monitoring and alternator charge input.

The tachometer pulse monitoring is used for safety related functions i.e. memory seat one-touch inhibition. The engine RPM thresholds for the tachometer pulse monitoring is as follows:

• Petrol 180 RPM +/- 10%
• Diesel 240 RPM +/- 10%.

The alternator charge input is used for load control of electrical functions. If certain functions are operating simultaneously, i.e. both rear windows operating and seat heaters active, the BECM will determine which function has priority and temporarily deactivate one function.