With Manufacturer's Scan Tool

Engine Speed (RPM) Sensor -G28-, checking

The engine speed sensor -G28- is a speed and reference mark sensor. The engine will not start if no speed signal is present. If the speed signal fails when the engine is running, it will cause the engine to stall immediately.

Special tools and equipment
- Test box VAG 1598/31
- Hand multimeter VAG 1526 or multimeter VAG 1715
- Adapter set VAG 1594
- Wiring Diagram

Test sequence
- Switch off ignition.
- Disconnect connector for engine speed sensor.






- Measure resistance between connector contacts 1+2.
Specification: 1.1 to 1.6k ohms

If the specification is not obtained:
- Replace engine speed sensor -G28. Fitting location overview.
- Check DTC memory and, if necessary, repair any malfunctions and then erase. [1][2]Reading Diagnostic Trouble Codes
- If the DTC memory has been erased or the Diesel Direct Fuel Injection Engine Control Module -J248- was disconnected from permanent battery positive (B+), the readiness code must be generated again. Monitors, Trips, Drive Cycles and Readiness Codes

If the specification is obtained:
- Remove wiper arms and plenum cover:






- Connect test box VAG 1598/31 to control unit wiring harness.






- Check wiring between test box and 3-pin connector for open circuit according to wiring diagram.
Terminal 1 + socket 102
Terminal 2 + socket 110
Terminal 3 + socket 86
Wire resistance: max. 1.5 Ohm

- Check wiring at 3 pin connector for short circuit to one another according to wiring diagram. Specification: Infinite Ohm

If no wiring malfunction is detected:
- Remove sensor and check sensor wheel for secure fit, damage and run-out.

If no malfunction is detected:
- Replace Diesel Direct Fuel Injection Engine Control Module -J248-.