Engine Speed Sensor, Checking

Engine Speed Sensor, Checking

The Engine Speed (RPM) Sensor -G28- is a speed sensor and reference mark sensor. The engine will not start if there is no engine speed signal. If the engine is running and the engine speed signal stops, the engine will stop immediately.

Recommended Special Tools, Workshop Equipment, Testers, Measuring Instruments and Auxiliary Items
- V.A.G 1526 portable multimeter or V.A.G 1715 multimeter
- Adapter set V. A. G 1594
- Wiring diagram

Test Sequence
- Measure sensor resistance between terminals 2+3 at connector to sensor.







Specification: 730 to 1000 Ohms

- Check sensor for short circuit between terminals 1 + 2 as well as 1 + 3.

Specification: Infinity Ohms

If the specifications are not obtained:
- Replace Engine Speed (RPM) Sensor -G28-.
- Erase DTC memory of ECM. Diagnostic Mode 04 - Erase DTC Memory
- Generate readiness code. Generate Readiness Code

If no malfunction is found on sensor:
- Connect test box to control module wiring harness. Test Box, Connecting For Wiring Test
- Check wires between test box and 3-pin connector for open circuit according to wiring diagram.

Terminal 1 + Socket 108
Terminal 2 + Socket 90
Terminal 3 + Socket 82







Wiring resistance: max. 1.5 Ohms

- Also check wires for short circuit to each other, to vehicle Ground (GND) and to B+.

Specification: Infinity Ohms

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

NOTE: There is a larger gap on sensor wheel. This gap is a reference mark and not damage.

If no malfunction can be detected at sensor wheel:
- Replace Motronic Engine Control Module (ECM) -J220-.