813457A 3 Mercury CAM KIT

The +24 Volt wire in the data link harness of the ECM is provided to power the Electronic Engine Control System service tools only. No other devices should be powered by this wire. The ECM was not designed to carry high current loads and is not short circuit protected.
The ECM draws a maximum of 6.5 Amperes at 24 volts from the electrical system under steady state conditions. While you are starting the engine, the ECM will draw a maximum of 9 Amperes. However, the Electronic Engine Control System will function with less than 24 volts. A minimum of 8 volts is required when the engine is cranked. A minimum of 24 volts is needed when the engine is running.Power enters the ECM through the + battery wire. Power exits the ECM through the negative battery wire. The Electronic Engine Control System is protected against power surges on the 24 Volt power supply. These power surges are due to alternator load dumps and due to jump starting with voltages up to 32 volts.Engine Speed Input Circuit
Engine speed is sensed by an electronic engine speed sensor. This is similar to an electromagnetic pickup. The signal is generated by placing the sensor near a rotating component. However, the sensor requires an operating voltage. The sensor requires an operating voltage of 8.0 0.4 Volts. This voltage is provided by the ECM.The output of the engine speed sensor is a voltage pulse. The frequency is dependent on the speed of the engine. The frequency of the pulse is interpreted by the ECM as engine speed. When you crank the engine, the frequency of the signal is 10 to 50 Hz (Hertz). The frequency of the signal is approximately 120 Hz at low idle.Fuel Rack Input Circuit
The engine fuel rack signal is obtained from an electronic linear position sensor. The sensor follows the movement of the rack assembly. This sensor requires an operating voltage of 8.0 0.4 Volts. The sensor requires a reference voltage of 5.0 0.25 Volts. These voltages are provided by the ECM.The output of the rack position sensor is a voltage between 0.3 and 5.25 Volts. This voltage is dependent upon the position of the rack position sensor. The output voltage is interpreted by the ECM as the rack position.Engine Coolant Temperature Circuit
The engine coolant temperature is obtained from an electronic sensor. The sensor is mounted on the engine. This sensor sends the data to the ECM through the engine wiring harness. The sensor requires an operating voltage of 8.0 0.4 Volts. The sensor operates at a temperature range between 40 to 120°C (104 to 248°F).At this range of input, the output of the coolant temperature sensor is good between 0.5 Volts and 4.5 Volts. This voltage is dependent upon the engine coolant temperature. The signal is interpreted by the ECM as the coolant temperature.Input Circuit for the Inlet Air Pressure
The inlet air pressure sensor is located on the engine. Inlet air pressure is taken before the turbocharger and after the air cleaner. The inlet air pressure is routed to the sensor. The sensor requires a reference voltage of 5.0 0.25 Volts.The output of the inlet air pressure sensor is a DC voltage between 1.0 Volts and 5.0 Volts. This voltage is dependent upon the pressure that is felt by the inlet air pressure sensor. The signal is interpreted by the ECM as absolute inlet air pressure.Boost Pressure Input Circuit
The boost pressure sensor is mounted in the air inlet manifold. The same operating voltages and the same reference voltages that are provided to the inlet air pressure sensor are also provided to this sensor.The output of the boost pressure sensor is a DC voltage between 0.35 Volts and 4.6 Volts. This voltage is dependent upon the pressure that is felt by the boost pressure sensor. The signal is interpreted by the ECM as boost pressure (gauge).Engine Oil Pressure Input Circuit
The engine oil pressure sensor is located in the engine oil lines. Engine oil pressure from the fuel injection pump is routed to this sensor. This sensor requires an operating voltage of 5 Volts.The output of the oil pressure sensor is a DC voltage between 0.35 Volts and 4.6 Volts. This voltage is dependent upon engine oil pressure. The signal is interpreted by the ECM as oil pressure.The engine oil pressure sensor is designed to measure oil pressure between 0 and 690 kPa (0 and 100 psi). Engine oil pressures that are greater than 690 kPa (100 psi) are read as 690 kPa (100 psi). This limited oil pressure reading range provides more accurate low oil pressure readings than a sensor that is capable of reading the maximum engine oil pressure. Low oil pressure readings are the most important oil pressure readings.Input Circuit for the Throttle Control
The throttle position is obtained from an electronic sensor. An operating voltage of 24 Volts is provided to the sensor by the electrical system.The output of the throttle position sensor is a constant frequency pulsed voltage of 0 to 5.25 Volts. The throttle position sensor regulates the pulse width of the signal that is generated. The frequency of the signal remains constant. The signal is interpreted by the ECM as the throttle position. The throttle position sensor's output pulse width is from 10 to 90%. The ECM interprets this signal. The ECM then generates a signal that represents the throttle position from 0 to 100%. Shutoff Solenoid Output Circuit
The shutoff solenoid is an output component of the Electronic Engine Control System. This solenoid must be energized in order for the engine to run.The output of the ECM to the shutoff solenoid is a pulsed voltage. This pulsed voltage can reach up to 6 Volts for about one half of a second after the power switch is turned ON for the purpose of pulling in the solenoid. This pulsed voltage can then drop off to approximately 1 Volt. This is adequate voltage to hold in the solenoid.The Electronic Engine Control System is