Engine Speed (RPM) Sensor -G28-, Checking

Component locations, refer to "Component Locations, Overview". Locations
NOTE: The engine speed sensor is a speed sensor and reference mark sensor. Without the signal from the - G28 - the engine cannot be started. If the signal from the - G28 - fails while the engine is running, the engine will switch off immediately.

Test sequence
- Before performing test, check sensor for proper installation and secure fit.
- Check harness connector of the engine speed sensor (identification: gray harness connector)





- Connect Multimeter between Terminals 2 and 3 for a resistance measurement.
- Specified value: 730 - 1000 ohm

NOTE: The resistance value of the engine speed sensor is relevant at a temperature of 20 °C. The resistance increases with increasing temperature.

If specified value is not obtained:
- Replace engine speed sensor.

If the specified value is met:
- Connect multimeter to terminal 2 and 1 (Ground) as well as to terminal 3 and 1 (Ground) for resistance measurement.
- Specified value: in each case Infinity ohm (no continuity)

If specified value is not obtained:
- Replace engine speed sensor.

If the specified value is met:
- Connect test box V.A.G 1598/31 at wiring harness to engine control module, the engine control module is not to be connected.





- Check the following wire connections for open circuit and short circuit between Ground and B+:

Harness connector Terminal V.A.G 1598/01 socket
1 (shielded) 108
2 (Ground) 90
3 (Signal) 82

- Repair open circuit or short circuit if necessary.

If no malfunctions are found in wires:
- Replace engine control module.