Sensors on electronically controlled diesel engines can be described as diverse, roughly divided into three types: pressure sensors, temperature sensors, speed and position sensors. There are about ten types of subdivisions. Today, I will introduce most of the necessary sensors for electronically controlled diesel engines.
1.Crankshaft speed sensor
Installation location: on the flywheel housing, next to the crankshaft pulley, on the engine block
Structure: Magnetic pulse type
Function: Used to measure engine speed and crankshaft angle.
2.Camshaft position sensor
Installation position: at the front end of the camshaft
Structure: Magnetic winding method
Function: Each revolution of the camshaft provides a signal to the ECU, and the ECU determines that the piston of that cylinder is at the top dead center of the compression stroke.
3.Common rail pressure sensor
Installation position: on the common rail pipe
Structure: Piezoresistive high pressure sensor, the highest frequency is 1 KHz, the measurement range is 0-200Mpa
Function: real-time measurement of the actual pressure signal in the common rail pipe and feedback to the ECU, increasing or decreasing the oil pressure
4.Coolant sensor
Installation position: on the thermostat body
Structure: Thermistor with negative temperature, its use range is 40-130°C
Function: Mainly used to measure the temperature of engine cooling, so as to further accurately control the fuel injection volume
5.Intake pressure sensor
Installation location: installed in the intake manifold
Structure: Semiconductor piezoresistive pressure sensor body
Function: Calculate the air volume, use the thermistor to control the air-fuel ratio and negative temperature fraction, so as to further accurately control the fuel injection volume.
6.Fuel temperature sensor
Location: On the main oil pipe
Structure: The thermistor of negative temperature counts, its use range is -40-130T.
Function: Used to provide fuel temperature signal to the engine control unit, generally set in the second stage fuel filter cover. The engine control unit corrects the fuel injection quantity according to the temperature change of the fuel, because the fuel expands and becomes less dense as the temperature rises.
7.Oil temperature sensor
Location: On the main engine oil pipe
Structure: Thermistor with negative temperature breakdown
Function: Used to provide engine oil temperature to the engine control unit, especially in cold conditions.
8.Water temperature sensor
Location: Located on the engine water outlet pipeline
Function: Measure and set the coolant temperature, used for correction of fuel injection quantity, torque correction, rail pressure correction and thermal protection.
9.Atmospheric pressure sensor
Location: The atmospheric pressure sensor is integrated in the ECU
Functions: Detect atmospheric pressure, measure altitude, and control the correction of fuel injection parameters.
10.Air flow meter
Location: Behind the air filter, on the intake pipe in front of the turbocharger
Function: Measure the amount of air entering the intake pipe for correction of the fuel injection setting.
11.Accelerator pedal position sensor
Position: On the accelerator pedal
Function: Measure the pedal stroke, reflect the driver’s intention, and use it for fuel injection calculation.
12.Knock sensor
Location: On the engine block
Function: Detect engine combustion status and accurately control pre-injection.
13.Moisture sensor
Location: On the engine block
Function: Detect engine combustion status and accurately control pre-injection.
