G28 engine speed sensor. 1.9 TDI PD from VAG Group. Family of diesel engines with injection pump-injector
G28 engine speed sensor
The G28 motor speed sensor is an inductive sensor. It is attached to the cylinder block.
Engine speed sensor wheel
The G28 engine speed sensor scans the sensor wheel 60-2-2 attached to the crankshaft. This means that the sensor wheel has 56 teeth with two gaps two teeth each. These gaps are located at an angle of 180 degrees and are guidelines for determining the position of the crankshaft.
The signal generated by the G28 engine speed sensor provides both engine speed and the exact position of the crankshaft. This information is used to calculate the injection point and the injection volume.
Consequences of signal failure
If the G28 engine speed sensor signal fails, the engine shuts down.
- G28 Engine speed sensor;
- J248 Direct fuel injection engine control module.
Quick start function
To ensure a quick start of the engine, the direct fuel injection engine control module J248 evaluates the signals generated by the camshaft position sensor G40 and the engine speed sensor G28. The J248 Direct Fuel Injection Engine Control Module uses a signal generated by the camshaft position sensor G40 to determine the relative position of the pistons in the cylinders when starting the engine. Because there are two gaps on the crankshaft sensor wheel, the direct fuel injection control module J248 of the diesel engine receives the appropriate signal from the G28 engine speed sensor only after half a turn of the crankshaft. Interpreting the signals from these two sensors, the direct fuel injection diesel engine control module J248 determines the position of the crankshaft according to the camshaft and thus the position of the pistons in the cylinders at an early stage. With this information, it can activate the correct solenoid valve at the appropriate time to initiate the injection cycle in the next cylinder and reach the compression stage. The quick-start function ensures that the engine is started early, as synchronization with the first cylinder is not required.
Read more about the family of diesel engines with injection pump-injector here .