Test the crankshaft position sensor

 

The crankshaft position sensor is used to determine the crankshaft's speed and position. The E.C.M. or ignition module uses this information to correctly time the spark at the spark plug with the piston. As the reluctor wheel on the crankshaft rotates, a voltage is created in the sensor that the E.C.M. interprets as crankshaft position. The sensor itself can be faulty or the wiring between the sensor and E.C.M. can be the problem.

 

To test the crankshaft position sensor:

1. Probe the connector wiring at the sensor. Small metal T-pins work great for this. Make sure the T-pins do not come into contact with each other.
2. Clip or hold the multimeter probes to each T-pin.
3. Set your meter to read AC milli-volts.
4. Record the reading while cranking the engine. A normal reading is 0.3 volts AC. At idle, the reading should be closer to one volt AC

If your unable to crank the engine:

1. Unbolt the sensor from the engine.
2. Measure the sensors resistance by connecting your meter's probes to each sensor prong.
3. The resistance should be between 100 and 600 ohms.

If the voltage readings at the sensor were not within specification, you'll need to check the wiring between the sensor and ignition module/E.C.M.

 

To test the crankshaft position sensor wiring:

For 2004 to 2006 Sportsters:

1. Measure the continuity between the sensor's red wire and ignition module terminal 8.
2. Measure the continuity between the sensor's black wire and ignition module terminal 9.
3. Continuity should be present on both wires.

 

For 2007 to 2013 Sportsters:

1. Measure the continuity between the sensor's red wire and E.C.M. position 30.
2. Measure the continuity between the sensor's black wire and E.C.M. position 12.
3. Continuity should be present on both wires.