With Generic Scan Tool

Engine Speed (RPM) Sensor -G28-, Checking

Recommended special tools and equipment







- VAG1526A hand multimeter
- VAG1594A connector test kit
- VAG1598/31 test box


NOTE: The engine speed (RPM) sensor detects RPM and reference marks. The engine cannot be started without a signal from the engine speed (RPM) sensor -G28-. If the engine speed (RPM) sensor -G28- signal fails while the engine is running, the engine will stop immediately.


Test requirement:
- Ignition switched off.

Work procedure
- Before performing test, check sensor for proper installation and proper fitting.







- Disconnect harness connector at Engine Speed (RPM) Sensor -G28- (item 3).







NOTE: Coolant reservoir screw (arrow) must be removed and coolant reservoir must be placed to the side in order to access harness connector. The coolant hoses remain connected.


Checking internal resistance







- Connect multimeter between terminal 2 and 3 for resistance measurement.
- Specified value: 730 ... 1000 Ohm


NOTE: Resistance value of the engine speed (RPM) sensor is based on a temperature of 20 degrees C. Resistance increases as temperature increases.


If specified value is not obtained:
- Replace Engine Speed (RPM) sensor (item 6).

If specified value is obtained:







- Connect multimeter to terminals 2 and 1 (shielding) and to terminals 3 and 1 (shielding) for resistance measurement.
- Specified value: Infinite Ohm each (no continuity)

If specified value is not obtained:
- Replace Engine Speed (RPM) sensor (item 6).

If specified value is obtained:

Checking wire connections
- Connect test box to wiring harness of Engine Control Module (ECM); ECM is not connected. Test Box, Connecting For Wiring Test







- Check the following wire connections for open circuit according to wiring diagram:

Harness connector Terminal Test box Socket
1 (shielding) 108
2 (Ground -GND-) 90
3 (signal) 82

- Specified value: Wire resistance max 1.5 Ohm

- Also check wires for short circuit to each other as well as to B+ and Ground (GND).
- Specified value: Infinite Ohm (no continuity)

- If necessary, repair wire connection.

If no malfunctions are detected:
- Replace Engine Control Module (ECM).

Final procedures
After repair work, the following work steps must be performed in the mentioned sequence:
1 - Check DTC memory, see "Mode 3: Check DTC memory". Test Box, Connecting For Wiring Test
2 - If necessary, erase DTC memory, see "Mode 4: Reset/erase diagnostic data". Diagnostic Mode 4: Reset/Erase Diagnostic Data
3 - Generate readiness code Readiness Code, Generating

- End diagnosis and switch ignition off.