Honda Civic 1992-1995 EG Engine Control Unit (ECU): input devices

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Click on the link to see the complete article with images check it out here: Engine Control Unit (ECU). Garage411.com Computerized engine controls are used to control fuel, ignition and emission control systems. Engine Control Unit (ECU) receives input signals from various sensors and components. ECU then compares each signal with a preprogrammed parameter in its memory. Based on this comparison, output signals are then adjusted to allow vehicle to perform optimally under all operating conditions. ECU is located under passenger-side carpet on Accord and Prelude. On Civic and Civic Del Sol, ECU is located behind passenger-side kick panel. FYI: Components are grouped into 2 categories. First category covers INPUT DEVICES, which control or produce voltage signals monitored by ECM. Second category is OUTPUT SIGNALS, which are components controlled by ECM. INPUT DEVICES Vehicles are equipped with different combination of input devices. Not all devices are used on all models. To determine component usage of a specific model, see appropriate wiring diagrams. Available input signals include the following: AC Switch Signal This switch signals ECM of demand for air conditioning. ECM then increases engine RPM to compensate for additional engine load. Alternator (FR) Signal This signals ECM when alternator field circuit is energized. ECM compensates for changes in idle speed and low battery voltage which can cause erratic injector pulse width. Automatic Transmission Shift Position Signal This signals ECM when transmission selector lever is in Park, Neutral or D4 position. Barometric Pressure (BARO) Sensor BARO sensor converts barometric (atmospheric) pressure into electrical signals and relays information to ECM. Battery Voltage (IGN.1) This provides ECM with battery voltage signal from ignition circuit when ignition is on. Brake Switch Signal This signals ECM when brake pedal is depressed. Electric Load Detector (ELD) This signals ECM when an electrical load (headlights, radio, etc.) exists so ECM can compensate for additional engine load. Engine Coolant Temperature (ECT) Sensor Coolant temperature sensor is a temperature-dependent variable resistor (thermistor). Resistance of thermistor decreases as coolant temperature increases. Exhaust Gas Recirculation Valve Lift Sensor EGR valve lift sensor detects amount of EGR valve lift and sends information to ECM. ECM uses this information, along with other sensor inputs, to determine regulation of EGR control solenoid valve. Intake Air Temperature (IAT) Sensor Intake air temperature sensor is a temperature-dependent variable resistor (thermistor). Thermistor resistance decreases as intake air temperature increases. Click on the link to see the complete article with images check it out here: Engine Control Unit (ECU). Garage411.com

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