Engine Speed (RPM) Sensor, Checking

Engine Speed (RPM) Sensor, Checking

Requirements
- RPM sensor properly installed (firmly seated)
- No metal shavings or damage on RPM sensor or sensor wheel

Checking
- Disconnect gray harness connector from RPM sensor.







- Connect multimeter US 1119 (Fluke 83 or equivalent) and measure resistance between connector terminals 1 and 2, using adapter cables from VAG1594 connector test kit.
Specified value: approx. 0.5 to 2 kohms

If resistance is outside specified range:
- Replace RPM sensor.

If resistance is OK:
- Check resistance between terminals 1 and 3, and between terminals 2 and 3.
Specified value: infinite ohms (no continuity)

If resistance is not as specified (infinite):
- Replace RPM sensor.
- Check readiness code. If DTC memory has been erased, generate new readiness code.
Refer "Monitors, Trips and/or Drive Cycle (Readiness Code)/Checking, Readiness Code" Testing and Inspection
Refer "Monitors, Trips and/or Drive Cycle (Readiness Code)/Generating, Readiness Code" Testing and Inspection

If resistance was as specified (no continuity):
- Check wiring between RPM sensor connector and ECM as follows:
- Connect VAG1598/19 test box to ECM harness connector. Refer to "Scan Tool Testing/Scan Tool Connecting and Initial Checks/VAG1598/19 Test Box, Connecting" Testing and Inspection







- Check wiring for open circuit, or short circuit to B+ or Ground, between 3-pin connector (sensor coupling) and ECM.

RPM sensor coupling terminal VAG1598/19 test box socket (ECM terminal)
1 A18
2 A17
3 D11 (Ground)







- If there are no open or short circuits:
- Replace ECM and generate new readiness code. Refer "Monitors, Trips and/or Drive Cycle (Readiness Code)/Generating, Readiness Code" Testing and Inspection