With Manufacturer's Scan Tool
Engine Speed (RPM) Sensor, 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, test equipment and auxiliary items
- VAG 1551 scan tool or VAG 1552 mobile scan tool with VAG 1551/3B cable
- VAG 1598/31 test box
- VAG 1526 hand multimeter or VAG 1715 multimeter
- VAG 1594 adapter set
- Electrical Wiring Diagram
Test sequence
- Separate gray 3-pin connector -1- to Engine Speed (RPM) Sensor -G28-.
- Measure sensor resistance between terminals 2 + 3 of connector to sensor.
Specification: 730 to 1000 Ohms
- Check sensor for short between terminals 1 + 2 as well as 1 + 3.
Specification: Infinity Ohms
If the specifications are not obtained:
- Replace Engine Speed (RPM) Sensor -G28-, item 13.
- Check DTC Memory, if necessary, repair any malfunctions and then Erase DTC Memory, Checking and Erasing DTC Memory. Reading Diagnostic Trouble Codes
- Read readiness code. If DTC memory has been erased or Motronic Engine Control Module (ECM) -J220- was disconnected from battery positive, readiness code must be generated again.
Monitors, Trips, Drive Cycles and Readiness Codes
Monitors, Trips, Drive Cycles and Readiness Codes
If no sensor malfunction is detected:
- Remove inner plenum chamber cover, left.
- Connect VAG 1598/31 test box to control module wiring harness. Motronic Engine Control Module (ECM) -J220- is not connected by this action.
- Check wiring for open circuit between test box and 3-pin connector using Electrical Wiring Diagram.
- terminal 1 + socket 108
- terminal 2 + socket 90
- terminal 3 + socket 82
Wire resistance: Max. 1.5 Ohms
- Additionally check wires for short to one another.
If no wiring malfunction is found:
- 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 Motronic Engine Control Module (ECM) -J220-.