Parts for your 2009 Toyota Prius-Crank angle sensor

2009 Toyota Prius crank-angle sensor (crankshaft position sensor)

Based on Toyota technical literature, the 2009 Prius does use a crank-angle sensor. The Toyota Repair Manual for the 2004–2009 Prius details diagnostics for DTCs P0335/P0339 and provides inspection procedures for the crankshaft position sensor, and Toyota’s parts catalogue lists a crankshaft position sensor for the 1NZ‑FXE engine used in this model. Those sources confirm the sensor is fitted and relevant to the vehicle.

On a 2009 Prius, the crank-angle sensor—also called the crankshaft position (CKP) sensor—feeds the engine control module precise information about crank speed and position. Even though the Prius is a hybrid and uses MG1 to spin the engine, the CKP still does the heavy lifting for spark timing, fuel injection phasing, misfire detection, and smooth engine start/stop handovers. Without a clean signal from this sensor, the engine may refuse to start, run roughly when the hybrid system brings it online, or drop into limp mode with the MIL lit.

There’s no scheduled maintenance for the CKP sensor itself, it’s a sealed, solid‑state Hall‑effect unit. However, good servicing practice on an ageing Prius includes checking the connector for corrosion, making sure the harness isn’t chafed, and keeping an eye out for oil leaks at the timing cover that could contaminate the sensor or O‑ring. If there are drivability niggles, scan for codes—P0335 (crank sensor circuit) or P0339 (intermittent) are the big clues.

Replacement is straightforward for a competent tech. The sensor sits low on the timing chain cover near the crank pulley. Steps usually look like this:

• Make the car safe: switch it off, remove the key/fob from the cabin, and disconnect the 12‑V negative terminal so the engine can’t start unexpectedly. Observe hybrid safety at all times.
• Access from under the front, unplug the connector, remove the small retaining bolt, and gently wiggle the sensor out.
• Lightly oil the new O‑ring, seat the new sensor, tighten the bolt to manufacturer spec, reconnect the plug, and refit any covers.
• Clear fault codes and verify a smooth engine start/stop during a short road test.

Using genuine or high‑quality aftermarket parts is recommended. If moisture, oil contamination, or wiring damage caused the issue, tidy that up during the job so the fix sticks. For many workshops this is a sub‑hour task, but allow a bit extra time if undertrays are fitted or fasteners are stubborn.

• Where is the crank-angle sensor on a 2009 Prius?
  It’s mounted low on the front of the engine at the timing chain end, right by the crank pulley on the timing cover. Most techs access it from underneath with the front end safely raised. The connector and single retaining bolt are easy to spot once the splash shield is out of the way.
• What fault codes point to a bad crank-angle sensor?
  The common ones are P0335 (Crankshaft Position Sensor “A” Circuit) and P0339 (Crankshaft Position Sensor “A” Circuit Intermittent). You might also see misfire codes if the signal drops out under load. Always check wiring and connector condition along with the sensor itself.
• Does the hybrid system change how the sensor works?
  Functionally it’s the same job—report crank speed and position—but the data is shared between the engine ECU and hybrid control ECU. The CKP lets MG1 synchronise engine starts seamlessly and keeps timing spot‑on during stop‑start transitions, which is why any CKP fault is felt most when the car tries to bring the engine in and out.