D Group 28 Design and Function Crankshaft Position (Engine Speed) Sensor The Crankshaft Position (Engine Speed) Sensor uses magnetic induction to generate a pulsed electrical signal. Notches are machined into the edge of the flywheel. When one of the notches passes close to the sensor, electric pulses result. The Crankshaft Position (Engine Speed) Sensor also indicates when the crankshaft is at the top dead center position. Differential Pressure DP Sensor The differential pressure sensor is used for flow measurement of the Diesel Particulate Filter (DPF). This sensor has two pressure ports and senses the difference in pressure between the two ports.
Measurement of the pressure before and after the DPF is used to calculate diesel filter regeneration. The Differential Pressure DPF Sensor is located on the side of the Diesel Particulate Filter (DPF). EGR Differential Pressure Sensor The EGR differential pressure sensor is used for flow measurement of the Exhaust Gas Recirculation (EGR) valve. This sensor has two pressure ports and senses the difference in pressure between the two ports. Measurement of the pressure before and after the EGR valve is used to calculate EGR flow. The EGR Differential Pressure Sensor is located on the left or right side of the engine.
EGR Temperature Sensor The EGR temperature sensor detects exhaust gas temperature for EGR system. The sensor modifies a voltage signal from the control unit. The modified signal returns to the control unit as the exhaust temperature of the EGR system to confirm EGR operation. The sensor uses a thermistor that is sensitive to the change in temperature. The EGR Temperature Sensor is located near the EGR valve. Engine Coolant Level (ECL) Sensor The Engine Coolant Level (ECL) Sensor is a switch. If engine coolant level falls below a calibrated point the contacts open and the driver will be notified of the low coolant level.
The Engine Coolant Level (ECL) Sensor is located in the cooling system reservoir tank. 4