With Generic Scan Tool

Engine Speed (RPM) Sensor -G28-, Checking

Recommended special tools and equipment







- VAG1526A 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.

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







- Disconnect electrical harness connector -2- from Engine Speed (RPM) sensor.

Checking internal resistance







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

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

If specified value is not obtained:
- Replace Engine Speed (RPM) sensor, -item 23-.

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: each Infinity Ohms (no continuity)

If specified value is not obtained:
- Replace Engine Speed (RPM) sensor, -item 23-.

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 Testing







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

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

- Specified value: Wire resistance max 1.5 Ohms
- Also check wires for short circuit to each other as well as to B+ and Ground (GND).
- Specified value: Infinity Ohms (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 "Mode 3: Check DTC memory". Diagnostic Mode 3: Check DTC Memory
2 - If necessary, erase DTC memory "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.