Engine Speed Sensor: Testing and Inspection

Fig. 3 Reference/RPM Sensor Plug Location:

Fig. 4 Reference/RPM Sensor Plug Terminal I.D.:

1. Unplug gray harness connector from plenum panel mount.
2. Check resistance between terminals 1 and 2 of the unplugged connector.
Resistance should be 1000 ohms.
3. If resistance is within specification, check resistance between terminals 1 and 3, and between 2 and 3 of the unplugged connector.
Circuit should be open (infinite resistance).
4. If resistance is not within specification, check wiring for open or short circuits.
5. If wiring is OK, replace the engine rpm sensor.