With Manufacturer's Scan Tool
Engine Speed (RPM) Sensor -G28-, Checking
Special tools and workshop equipment required
- V.A.G 1526 A Multimeter
- V.A.G 1594 A Connector test kit
- V.A.G 1598/31 Test box
Component location Figure 6.
NOTE: The engine speed (RPM) sensor is a combined speed sensor and reference mark sensor. The engine cannot be started without a signal from the Engine speed (RPM) sensor -G28-. If the signal from the Engine speed (RPM) sensor -G28- fails while the engine is running, the engine will cut out immediately.
Work sequence
- Before performing test, make sure that sensor is correctly installed and firmly seated.
- Disconnect Engine speed (RPM) sensor connector -G28- -Pos. 3-.
NOTE: To gain access to the connector, remove coolant expansion tank bolt (arrow) and move expansion tank to the side. Fuel hoses remain connected.
- Connect multimeter between terminals 2 and 3 to measure resistance.
Specified value: 730...1000 Ohms
NOTE: The resistance value of the Engine speed (RPM) sensor -G28- is associated with a temperature of 20 degrees C. The resistance increases if the temperature increases.
If specified value is not obtained:
- Install new Engine speed (RPM) sensor -G28-.
If specified value is obtained:
- Connect multimeter between terminals 2 and 1 -screen- and 3 and 1 -screen- to measure resistance.
Specified value: each case Infinite Ohms (no continuity)
If specified value is not obtained:
- Install a new Engine speed (RPM) sensor -G28-.
If specified value is obtained:
- Connect test box V.A.G 1598/31 to wiring harness for ECM; do not connect ECM. Test Box, Connecting For Wiring and Component Test
- Check for open circuit, short to positive, or short to ground in following wiring connections:
Connector Test box V.A.G 1598/31
terminal Socket
1 (screening) 108
2 (ground) 90
3 (signal) 82
- Repair any open/short circuit as necessary.
If no wiring problems are found:
- Replace ECM.