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| Illustration 1 | g01049490 |
(1) Fuel pressure sensor (RH service) (2) Coolant temperature sensor (3) Turbocharger outlet pressure sensor (4) Inlet air temperature sensor (5) Customer connector (6) Coolant level sensor (7) Fuel temperature sensor (8) Fuel pressure sensor (LH service) (9) Secondary speed/timing sensor (cam) (10) Transmission oil pressure sensor (11) Transmission oil temperature sensor (12) Primary speed/timing sensor (crankshaft) (13) Engine oil pressure sensor (14) ECM connector J2/P2 (15) ECM connector J1/P1 | |
The electronic control module ECM is integrally designed into the engine's fuel system and the engine's air inlet and exhaust system in order to electronically control the fuel delivery and the injection timing. The ECM provides increased timing control and fuel air ratio control in comparison to conventional mechanical engines. Injection timing is achieved by precise control of injector firing time, and engine rpm is controlled by adjusting the firing duration. The ECM energizes the solenoid in the unit injector in order to start the injection of fuel. Also, the ECM de-energizes the unit injector solenoids in order to stop injection of fuel. Refer to the Systems Operation, "Fuel System" topic for a complete explanation of the fuel injection process.
The engine uses the following types of electronic components:
- Inputs
- Controls
- Outputs
An input component is one that sends an electrical signal to the ECM. The signal that is sent varies in one of the following ways:
- Voltage
- Frequency
- Pulse width
The variation of the signal is in response to a change in some specific system of the vehicle. The electronic control module sees the input sensor signal as information about the condition, environment, or operation of the vehicle.
The ECM receives the input signals. Electronic circuits inside the ECM evaluate the signals from the input components. These electronic circuits also supply electrical energy to the output components of the system. The electrical energy that is supplied to the output components is based on predetermined combinations of input signal values.
An output component is one that is operated by a control module. The output component receives electrical energy from the ECM. The output component uses that electrical energy in one of two ways. The output component can use that electrical energy in order to perform work. The output component can use that electrical energy in order to provide information.
- As an example, a moving solenoid plunger will perform work. By performing work, the component has functioned in order to regulate the vehicle.
- As an example, a dash panel light or an alarm will provide information to the operator of the vehicle.