Engine Speed (RPM) Signal, Checking

Engine Speed (RPM) Signal, Checking

Vehicles with automatic transmission:

NOTE: The signal is generated by the engine speed (RPM) sensor -G28- processed in the Engine Control Module (ECM) and directed to various parts of the electronic system (e.g. control module for A/C or ABS / EDS) from terminal 37 of the ECM. Engine speed signal and wire connections are monitored by these systems.

- Check engine speed (RPM) sensor -G28-
- Connect test box V.A.G 1598/31 to wiring harness for Engine Control Module (ECM); do not connect Engine Control Module (ECM).
- Check for open circuit and short to positive (B+) or ground (GND) in following wiring connections:
- Test box VAG 1598/31 Socket - 37 (Instrument cluster terminal)
- Repair any open/short circuit as needed.

If no problems with wiring are found:
- Checking CAN bus.