P0389 Subaru Crankshaft Position Sensor B Circuit Intermittent

Possible causes

– Faulty crankshaft position sensor
– Crankshaft position sensor harness is open or shorted
– Crankshaft position sensor circuit poor electrical connection
– Signal plate may be damage
– Starter motor may be faulty
– Starting system circuit
– Dead or weak battery

Tech description

Sometimes and in some models, low battery voltage or a weak starter can can trigger a Crankshaft Position Sensor code. Before replacing any parts, recharge or replaced battery.

What about the obd code?

The crankshaft position sensor (POS) signal is sent to the Electronic Control Module (ECM) during the first few seconds of engine cranking is intermittent

Symptoms

– Engine Light ON (or Service Engine Soon Warning Light)
– Lack/Loss of Power
– Engine Stall

P0389 Subaru Description

The Crankshaft position sensor also known as the crank position sensor is an electronic device used in an engine to record the rate at which the crankshaft is spinning. This information is used by the Electronic Control Module (ECM) to control ignition and fuel injection. The sensor system consists of a rotating part, typically a disc, as well as a static part, the actual sensor.

When the engine is running, the high and low parts of the teeth cause the gap with the sensor to change. The changing gap causes the magnetic field near the sensor to change. The change in the magnetic field cause the voltage from the sensor to change.