816856Q 3 Mercury FUEL CONNECTOR

Illustration 1 g02696199
Typical exampleLeft side view of engine (1) Secondary engine speed/timing sensor (2) Intake manifold pressure sensor (Boost) (3) Front valve cover connector (4) Intake manifold air temperature sensor (5) Fuel temperature sensor (6) Rear valve cover connector (7) Primary engine speed/timing sensor (8) Timing calibration port (9) Atmospheric pressure sensor (10) Engine oil pressure sensor (11) Engine Control Module (ECM) (12) J2/P2 ECM connector (13) J1 ECM connector
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Right side of engine (14) Sensor for the intake valve actuation pressure (15) Solenoid for the intake valve actuation pressure (16) Coolant temperature sensor (17) Diverter valve for the engine coolantEngine Monitoring
The electronic control system includes engine monitoring. The system monitors engine oil pressure, coolant temperature and coolant level. All truck engines are shipped from the factory with the following sensors: engine oil pressure sensor and coolant temperature sensor. The Original Equipment Manufacturer (OEM) is responsible for providing and installing the coolant level sensor. The coolant level sensor is the only sensor that can be individually selected for engine monitoring. The software for the Engine Control Module (ECM) contains a customer programmable parameter that enables the coolant level sensor. The default factory setting is "NO". The ECM customer programmable parameters have four levels that are for engine monitoring:
Warning (factory default)
Engine derate
Engine shutdownWarning Mode
Warning mode uses the following sensors: engine oil pressure, coolant temperature and optional coolant level sensor. When a diagnostic code is active, the check engine lamp will flash and the warning lamp will come on.Engine Derate and Engine Shutdown
The engine derate and the engine shutdown allows the ECM to alter engine performance in order to avoid damage to the engine. The engine should return to normal conditions once the problem is corrected. When the engine is derated, the check engine lamp and the warning lamp will flash. For the operating conditions that cause these modes, refer to the appropriate section for the sensor.Electronic Control System Operation
The fuel delivery and injection timing are electronically controlled. In comparison to engines that are controlled mechanically, the electronic control system provides increased control of timing and increased control to the fuel to the air ratio. Injection timing is achieved by precise control of injector firing time, and engine power is controlled by adjusting the firing duration. The ECM energizes the fuel injection solenoid in order to start the injection of fuel. The ECM will de-energize the fuel injection solenoid in order to stop the injection of fuel. Refer to the Systems Operation, "Fuel System" for a complete explanation of the fuel injection process.The engine uses the following types of electronic components: input, control and output.An input component is one that sends an electrical signal to the ECM. The signal that is sent varies in either voltage or in frequency when there is a change in some specific system of the vehicle. An example would be the engine speed/timing sensors or the coolant temperature sensor. The ECM sees the input sensor signal as information about the condition, environment, or operation of the vehicle.An electronic control system component receives the input signals. Electronic circuits that are inside the ECM evaluate the signals. The ECM then supplies electrical energy to the output components of the system, which are in response to predetermined combinations of input signal values.An output component is one that is operated by the ECM. An output component receives electrical energy from the ECM. The electrical energy is used to perform one of the following functions:
Perform work. An example would be moving a solenoid plunger. An output component takes an active part in regulating or operating the vehicle.
An output component can give information or a warning. An example would be a light or an alarm to the operator of the vehicle or other person.Output components control the engine operation electronically in order to improve the following items: performance, fuel consumption rate and reduced emissions levels. A brief description of the sensors that are used in the electronic control system follows:Atmospheric Pressure Sensor
The atmospheric pressure sensor is an absolute pressure sensor that measures crankcase pressure. Both the boost pressure and the oil pressure are communicated to the service tools and over the data link. The two pressures are calculated by subtracting the reading for the atmospheric pressure sensor. The atmospheric pressure sensor measures pressure from 0 to 116 kPa (0 to 17 psi). The atmospheric pressure sensor is supplied with + 5 VDC by the ECM.Intake manifold pressure sensor (Boost)
The intake manifold pressure sensor is an absolute pressure sensor that measures inlet manifold pressure. The difference between the measurement of the inlet manifold pressure and the pressure that is measured by the atmospheric pressure sensor is called the boost pressure. The information is communicated to Caterpillar Electronic Technician (ET) and over the data link. The intake manifold pressure sensor measures pressures from 20 to 550 kPa (3 to 80 psi). The intake manifold pressure sensor is supplied with + 5 VDC by the ECM.Coolant Level Sensor
The coolant level sensor is installed by the vehicle OEM. The coolant level sensor is an optional sensor. The coolant level sensor is selected through the ECM customer programmable parameter. The ECM customer programmable parameters can be protected by customer passwords.Coolant Temperature Sensor
The engine coolant temperature is measured by an electronic sensor that is mounted on the water temperature regulator housing. The coolant temperature signal is used to modify the amount of the fuel that is delivered to the engine and the engine timing for improvement during cold starts and white smoke cleanup. The ECM supplies the coolant temperature sensor with 5.0 0.5 VDC. The sensor output voltage is + 0.5 VDC to + 4.5 VDC. The sensor output voltage depends on the engine coolant temperature. Coolant temperature is used to indicate the cold mode operation and coolant temperature is used for engine monitoring.Coolant Temperature Engine Monitoring Operation
The check engine lamp will flash if engine monitoring is programmed to derate the engine. The check engine lamp will flash if engine monitoring is programmed to shut down the