Parts for your 2016 Subaru Impreza-Crank angle sensor

2016 Subaru Impreza crank-angle sensor: what it does, and when to replace it

Based on Subaru’s Factory Service Manual for the 2016 Impreza (GJ/GP, FB20 engine) and the Subaru electronic parts catalogue, the vehicle is fitted with a crankshaft position sensor — functionally the same thing many techs call a “crank-angle sensor”. The FSM lists diagnostic procedures for DTC P0335–P0339 (Crankshaft Position Sensor Circuit), confirms live data use by the ECM for ignition and fuel timing, and shows the sensor as a serviceable component. This aligns with standard OBD-II references (e.g., SAE J1979) that define crank position monitoring for engine management. So yes, the 2016 Subaru Impreza does use a crank-angle/position sensor.

On the 2016 Impreza’s FB20, the crank-angle sensor constantly reports the crankshaft’s speed and exact position to the engine control module. The ECM uses that info to fire the coils and injectors at precisely the right moment, manage start-up, stabilise idle, and coordinate with the cam sensors for variable valve timing. If the sensor signal drops out or goes wobbly, the car can be hard to start, stall at idle, misfire, or not start at all. You’ll often see the check engine light with a P0335-type code.

There’s no scheduled replacement — the sensor is designed to last the life of the vehicle. As part of routine servicing, a good workshop will visually check the wiring and connector under the bonnet, make sure there’s no oil contamination at the sensor boss, and scan for pending fault codes. Because the FB20’s sensor uses a fixed air gap and an internal Hall/magnetic element, there’s no adjustment or cleaning spec, if it’s faulty, it’s replaced.

If replacement is needed, a mechanic will disconnect the battery, access the sensor on the engine block, unplug the connector, remove the retaining bolt, and pull the sensor straight out. A light wipe of clean engine oil on the new O-ring helps it seat without nicks. The retaining bolt should be tightened to the factory torque spec from the Subaru service manual, and the harness routed exactly as original to avoid chafing. After fitment, they’ll clear codes and confirm stable crank signal and timing correlation in scan data.

• Common symptoms: hard starting, random stalling, sudden loss of power, tachometer drop, MIL on with P0335–P0339.
• Helpful tip: rule out damaged wiring or poor grounds before condemning the sensor.
• Typical workshop time: around 0.5–1.0 hour, depending on access and corrosion.

FAQs

Where is the crank-angle (crankshaft position) sensor on a 2016 Subaru Impreza?
It’s mounted to the engine block and reads a toothed reluctor on the crankshaft. On the FB20, it’s accessible from the engine bay, the tech removes a single retaining bolt and an electrical connector to extract it. Exact location can vary slightly by market trim, but it’s typically near the rear of the block.

What are the signs the crank-angle sensor is failing?
Look for long crank times, intermittent stalling, rough running at low speed, and the check engine light. A scan tool may show P0335–P0339. Live data will often reveal dropouts in engine speed (RPM) when the fault occurs.

Does the crank-angle sensor need regular servicing or calibration?
No scheduled service is required. There’s no calibration or gap adjustment on the FB20 — it’s a fixed, solid-state unit. During normal servicing, a quick check for oil leaks, connector security, and wiring condition is all that’s needed unless faults are logged.