Engine Speed (RPM) Sensor -G28, Checking

Engine Speed (RPM) Sensor -G28, Checking

Function: The engine (RPM) Sensor -G28- detects engine speed and reference marks. Without an engine speed signal, the engine will not start. If the engine speed signal fails while the engine is running, the engine will stop immediately.

Recommend special tools and equipment

- VAG1526 Multimeter or VAG1715 Multimeter
- VAG1594 Connector test kit
- Wiring diagram

Work sequence

- Disconnect the gray 3-pin harness connector to engine speed (RPM) sensor.





- Measure sensor resistance between terminals 2 and 3 at connector to sensor.
Specified value: 730 to 1000 ohms

- Check sensor for short circuit between terminals 1 and 2 as well as 1 and 3.
Specified value: Infinite ohms

If specified values are not obtained:
- Replace Engine Speed (RPM) Sensor -G28-
- Erase DTC memory of Engine Control Module.

- Generate a readiness code.

If no DTC is found on the sensor:

- Connect test box to control module wiring





- Check wires between test box and 3-pin connector for open circuits according to wiring diagram.

Terminal 1 & socket 108
Terminal 2 & socket 90
Terminal 3 & socket 82

Wire resistance max: 1.5 ohms

- Check wires for short circuits to each other, to vehicle Ground (GND) and to B+.

Specified value: Infinite ohms

If no wiring faults are found:
- Remove sensor and check sensor wheel for secure fit, damage, and run-out.

Note: There is a larger-sized gap on the sensor wheel. This gap is the reference mark and does not mean that the sensor is damaged.

If nothing seems to be wrong with the sensor wheel
- Replace Motronic Engine Control Module (ECM) -J220-.