With Manufacturer's Scan Tool
Engine Speed (RPM) Sensor -G28-, Checking
The engine speed (RPM) sensor -G28- is a speed and reference mark sensor. The engine will not start if there is no speed signal. If the speed signal fails when the engine is running, it will cause the engine to stall immediately.
Special tools and equipment
- V.A.G1551 Scan Tool (ST) or VAG-1552 mobile scan tool with VAG1551/3 adapter cable
- VAG1598/22 test box
- Multimeter (Fluke 83 or equivalent)
- VW1594 adapter set
- Wiring diagram
Test sequence
- Disconnect grey 3-pin harness connector (arrow) from engine speed sensor.
- Measure sensor resistance between terminals 2 + 3 of harness connector to sensor.
Specified value: 480-1000 ohms
- Check sensor for short between terminals 1 + 2 as well as -1- + -3-.
Specified value: Infinity ohms
- If the specified values are not obtained:
- Replace engine speed (RPM) sensor -G28-, refer to item 27, Locations
- Check DTC memory. If necessary, repair any malfunctions and erase DTC memory.
Reading Diagnostic Trouble Codes
Clearing Diagnostic Trouble Codes
- Display readiness code. Monitors, Trips, Drive Cycles and Readiness Codes
If DTC memory has been erased or the Engine Control Module (ECM) was disconnected from permanent battery (B+) voltage, generate the readiness code again. Monitors, Trips, Drive Cycles and Readiness Codes
If no sensor malfunction is detected:
- Remove wiper arms and plenum chamber cover.
- Connect VAG1598/22 test box to control module wiring harness.
- Check wiring between test box and 3-pin harness connector for open circuit according to wiring diagram.
- Terminal -1- + socket 67
- Terminal -2- + socket 63
- Terminal -3- + socket 56
- Wire resistance: max. 1.5 ohms
- Additionally check wires for short to one another.
- Terminal -1- + socket 63
- Terminal -1- + socket 56
- Terminal -2- + socket 67
- Specified value: Infinity ohms
If no malfunction is found in the wiring:
- Remove sensor and check sensor wheel for secure fit, damage and run-out.
NOTE: There is a larger gap on the sensor wheel. This gap is the reference mark and does not mean that the sensor wheel is damaged.
If no malfunction is detected on sensor wheel:
- Replace Engine Control Module (ECM).