Control system and method of operating a control system

Abstract

An electronic control unit suitable for a motorcycle provides diagnostic support, tachometer drive and warning lamp drive all multiplexed onto one pin and driven by a single driver circuit. In a diagnostics mode, the pin is connected to diagnostic equipment. When a diagnostic test has been completed, a tachometer drive signal is output on the pin, the drive signal having a duty cycle set high enough to illuminate the warning lamp if a fault condition is detected by on-board sensors. By combining multiple functions onto a single pin with a single driver circuit, the cost of implementing an engine control unit may be reduced compared with existing arrangements which require separate pins and drivers for each function.

Dependencies are inferred from the claim text.