Structure: electromagnetic type and Hall type

Function: The speed sensor collects the diesel engine speed signal so that the ECU can calculate the circulating fuel supply. It can also provide the crankshaft position signal so that the ECU can accurately control the fuel injection timing; the auxiliary speed sensor is used as the speed signal to calculate the crankshaft angle signal to judge the cylinder.

Installation location: behind the flywheel housing and the fan. The gap between the sensor and the signal plate is 0.5-1.5mm. Synchronization state: The synchronization signal is 48 for Bosch National III and 30 for Bosch EDC17 National IV system.

Working voltage: The electromagnetic type has no working voltage, and the resistance is about 860 ohms. The Hall type has three working voltage wires: 5V, signal, and ground.

Trouble phenomenon: 1. It is not easy to start 2. White smoke is emitted 3. The power is insufficient 4. The pressure relief valve is opened when the ECU is repaired (usually the signal plate is bounced, and the repairman replaces the signal plate not standard) 5. Can not start