Top Dead Center Sensor: Operation

• The top dead center sensor functions to detect the top dead center position of the No. 1 cylinder and to convert those data to pulse signals that are input to the engine control unit. The engine control unit, based upon those signals, calculates the sequence of fuel injection.
• The power for the top dead center sensor is supplied from the control relay and is grounded to the vehicle body. The top dead center sensor, by intermitting the flow (to ground) of the 5-volt signal from the engine control unit, produces pulse signals. See Fig 1 .

Fig 1: Identifying Top Dead Center Sensor Circuit

Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.