With Manufacturer's Scan Tool

Engine Speed (RPM) Sensor -G28-, Checking

The engine speed (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.

Special tools and equipment
- V.A.G1551 scan tool (or VAG1552 mobile scan tool) with VAG1551/3 cable
- VAG1598/31 test box
- Multimeter Fluke 83 or equivalent
- VAG1594 connector test kit
- Wiring diagram

Test sequence






- Disconnect gray 3-pin harness connector -1- leading to the engine speed (RPM) sensor.






- Measure resistance of sensor between terminals 2 + 3 at connector to sensor.
Specification: 730 to 1000 Ohms

NOTE: Resistance value is valid at approx. 20°C. At higher temperatures, resistance value increases.

- Check sensor for shorts between terminals 1 + 2 and 1 + 3.
Specification: Infinity Ohms

If specified values are not obtained:
- Replace engine speed (RPM) sensor -G28-.
- Check DTC memory, repair any malfunctions and then erase DTC memory.
Clearing Diagnostic Trouble Codes
Reading Diagnostic Trouble Codes

If no DTC is found on sensor:
- Remove wiper arms and wind cowl






- Connect VAG1598/31 test box to control module wiring harness. Engine Control Module (ECM) is not connected.
- Check wires between test box and 3- pin connector for open circuits according to wiring diagram.
Terminal 1 and test box socket 108
Terminal 2 and test box socket 90
Terminal 3 and test box socket 82
Wire resistance: max: 1.5 Ohms






- Also check wires for short circuit to each other.
Specification: Infinity Ohms

If wiring is OK:
- Remove sensor and check sensor wheel for secure fit and damage.

NOTE: There is a larger-sized gap on the sensor wheel. This gap is a reference mark, not damage.

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