If you own a Subaru Outback and are experiencing engine performance issues, locating the crankshaft position sensor is a critical diagnostic step. This sensor is essential for proper engine timing and fuel delivery. In this comprehensive guide, we cover everything from sensor location across different model years to symptoms, replacement procedures, and cost estimates.

Understanding the Crankshaft Position Sensor

The crankshaft position sensor (also called a crank sensor) is a magnetic or Hall-effect sensor mounted near the crankshaft. It monitors the rotational speed and position of the crankshaft and sends a signal to the engine control unit (ECU). The ECU uses this data to determine ignition timing, fuel injection timing, and to detect engine misfires. A failing sensor can cause a range of drivability problems, from hard starting to complete engine stall.

In Subaru Outback models, the sensor is a two-wire or three-wire device that generates an AC voltage signal as the reluctor ring on the crankshaft passes by. The frequency and amplitude of this signal allow the ECU to calculate engine speed and position. Without a functioning sensor, the ECU cannot synchronize fuel and spark, and the engine will not run.

How It Differs From a Camshaft Position Sensor

Many Outback owners confuse the crankshaft position sensor with the camshaft position sensor. While both provide timing information, the crank sensor monitors the crankshaft’s rotation, while the cam sensor tracks the camshaft’s position for sequential fuel injection. The crank sensor is more fundamental – if it fails, the engine will usually not start at all. The cam sensor failure may cause rough running or a check engine light, but the car can often still drive.

Common Causes of Crankshaft Position Sensor Failure

Understanding why these sensors fail can help you diagnose issues faster and potentially avoid premature replacement. Common failure modes include:

  • Heat damage – The sensor is often located near exhaust components or the engine block. Prolonged exposure to high temperatures can degrade the internal electronics, causing intermittent or complete failure.
  • Oil contamination – A leaking valve cover gasket or oil separator can allow oil to seep into the sensor connector or onto the sensor tip, interfering with the magnetic signal.
  • Physical damage – Debris from a failing timing belt tensioner or water pump can strike the sensor. In some Outback models, the sensor is exposed and can be struck by road debris.
  • Wiring harness issues – Chafed, broken, or corroded wires in the sensor pigtail can cause intermittent signal loss, especially as the engine moves on its mounts.
  • Manufacturing defects – Some early FB engine sensors had a higher failure rate due to internal wire bond failures. Subaru later released an updated part number.

Symptoms of a Bad Crankshaft Position Sensor in a Subaru Outback

Pay attention to these warning signs. They can indicate a failing crank sensor, though other components (ignition coil, fuel pump, ECU) can produce similar symptoms.

Symptom Description
Engine cranks but won’t start No spark or fuel injection because the ECU receives no crank signal. This is the most common symptom of a completely failed sensor.
Intermittent stalling The engine dies while driving, then restarts after a short wait. This happens when the sensor’s output drops below the ECU threshold, often when hot.
Hard starting or long crank time The engine needs to crank for 5–10 seconds before starting, especially when cold. The sensor may be providing a weak signal.
Check engine light (codes P0335, P0336, P0339) These codes specifically indicate a crankshaft position sensor circuit malfunction, range/performance, or intermittent signal.
Engine misfire or rough idle If the sensor’s signal is noisy or intermittent, the ECU may misadjust ignition timing, causing a misfire at idle or low RPM.
Loss of power under load A failing sensor can cause the ECU to go into a “limp” mode with reduced power. This is dangerous when merging or climbing hills.

Important: If you experience the “no start” condition, do not repeatedly crank the engine. This can flood the cylinders with fuel and damage the catalytic converter. First, verify that the crank sensor is the cause by testing (see below).

Where Is the Crankshaft Position Sensor Located in a Subaru Outback?

The location varies slightly depending on whether your Outback has an EJ-series engine (1995–2014 model years approximate) or the newer FB-series engine (2013–present). But in all cases, the sensor is mounted on the front or side of the engine block, very close to the crankshaft pulley (harmonic balancer).

Location for Subaru Outback with EJ Engine (2000–2014 Legacy/Outback, also 1990–1999 models)

In EJ engines (EJ25, EJ22, EJ20), the crankshaft position sensor is located on the front side of the engine block, behind and slightly above the crankshaft pulley. To access it:

  1. Look at the lower front of the engine, just behind the serpentine belt path.
  2. You will see a cylindrical sensor (about the size of your thumb) mounted vertically or at a slight angle into the block, with a two-wire connector pointing upward or toward the driver’s side.
  3. It is held in place by a single 10mm bolt (sometimes two).
  4. The sensor is usually black or dark gray with a plastic body.

On many EJ models, the sensor is partially hidden under the intake manifold’s front bracket or behind the power steering pump pulley. Use a flashlight and mirror if needed. On 2005–2009 Outbacks (3.0L H6), the crank sensor is on the lower right (front passenger side) of the engine, near the harmonic balancer.

Location for Subaru Outback with FB Engine (2013–Present, also 2010–2012 Legacy/Outback with 2.5L FB)

The FB engine (FB25, FA20 in some models) has the crankshaft position sensor mounted on the left (driver’s side) of the engine block, near the starter motor. It sits just above the crankshaft pulley, facing the transmission bellhousing. To find it:

  1. From the driver’s side wheel well (or under the car), look at the lower rear area of the engine block.
  2. You will see a small sensor with a connector that points toward the firewall. It is bolted to the block with a single 10mm bolt.
  3. In some FB models, the sensor is mounted directly above the starter motor, so removing the starter may be necessary for replacement.

Note: The FB engine sensor is more recessed than the EJ version. You may need to access it from underneath the vehicle, after removing the underbody cover. A ratchet extension and universal joint are helpful.

Step-by-Step Guide to Locate the Sensor in Your Subaru Outback

If you want to visually confirm the sensor before buying parts, follow this systematic approach:

What You’ll Need

  • Flashlight or work light
  • Small mirror (optional)
  • 10mm socket, ratchet, and extension
  • Wheel blocks and jack stands (if you need to go under the car)

Procedure

  1. Park on level ground, apply the parking brake, and disconnect the negative battery terminal for safety.
  2. Open the hood and remove any plastic engine covers if present. On some Outbacks, you may need to remove the air intake duct for better visibility.
  3. Locate the crankshaft pulley (harmonic balancer) at the front of the engine. It is a large metal disc with a rubber center, driven by the serpentine belt.
  4. Identify the sensor’s mounting boss. Look for a small protruding nub on the engine block (or a separate bracket) within 2–3 inches of the pulley’s circumference. The sensor will plug into that nub.
  5. Trace the electrical connector. The sensor has a two-wire harness that runs up toward the top of the engine. Follow it back to the sensor.
  6. If you cannot see the sensor from above, raise the vehicle safely and look from below. On FB engines, the sensor is easier to spot from underneath, near the oil pan and starter.
  7. Once found, note the orientation and bolt(s) so you can install the new sensor in the same position. The gap between the sensor tip and the reluctor ring is factory-set and not adjustable – simply tighten the bolt.

Testing the Crankshaft Position Sensor

Before replacing the sensor, test it to confirm it is the cause of your problem. There are two common methods:

Using a Multimeter (Resistance Test)

  1. Disconnect the sensor harness.
  2. Set your multimeter to ohms (Ω) and measure across the two pins in the sensor connector.
  3. For most Subaru crank sensors (magnetic type), you should see a reading between 200 and 600 ohms at room temperature. Refer to your service manual for exact specs.
  4. If the reading is out of range (open or shorted), the sensor is faulty.

Using a Multimeter (AC Voltage Test)

  1. Reconnect the sensor and probe the back of the connector (or use a breakout wire).
  2. Set the multimeter to AC volts.
  3. Crank the engine (with fuel pump relay removed to prevent starting) and watch for an AC voltage signal, typically 0.5V to 2V AC at cranking speed.
  4. If no voltage is produced, the sensor is likely dead.

Caution: Do not short the sensor pins while the engine is running – it can damage the ECU. If you are not comfortable with electrical testing, replace the sensor based on symptoms and diagnostic trouble codes (DTCs).

Replacing the Crankshaft Position Sensor in a Subaru Outback

Once you’ve confirmed the sensor is bad, replacement is straightforward. Here’s a general procedure that applies to most Outback models (always consult your specific repair manual).

Parts and Tools

  • New crankshaft position sensor (OEM Subaru or quality aftermarket like Denso, NTK, or Hitachi)
  • 10mm socket, ratchet, extensions
  • Flathead screwdriver (to release connector lock)
  • Dielectric grease (optional, for connector)
  • Torque wrench (for engine block bolts – typically 5–8 ft-lbs, but verify)

Replacement Steps

  1. Disconnect the negative battery terminal.
  2. Unplug the electrical connector from the sensor. Press the locking tab and pull.
  3. Remove the mounting bolt(s). The sensor is often secured with a single 10mm bolt. In some FB engines, you may need to remove the starter motor to access the bolt.
  4. Gently wiggle the sensor out of its bore. If it’s stuck, use a small pry bar or tap lightly. Do not damage the sealing O-ring or the sensor tip.
  5. Inspect the sensor tip for metal debris (normal) or signs of rubbing. If it has collided with the reluctor ring, the engine may have additional issues.
  6. Install the new sensor: apply a thin film of engine oil to the O-ring for easier insertion. Slide it into the bore until fully seated. The gap is pre-set by the sensor body – do not add shims.
  7. Install the mounting bolt and torque to specification (typically 5–8 ft-lbs, but use your manual). Over-tightening can crack the sensor body.
  8. Reconnect the electrical connector until it clicks.
  9. Reinstall any removed components (starter, covers, air intake).
  10. Reconnect the battery negative terminal.
  11. Clear any DTCs from the ECU using a scan tool, or drive the car for a few miles. The check engine light should turn off.

Note: On some Outback models (especially 2010–2012 with EJ25), the sensor is in a tight spot near the steering rack. You may need a shorter socket or a wobble extension. Be patient.

How Much Does It Cost to Replace a Crankshaft Position Sensor on a Subaru Outback?

The cost varies by model year and whether you do it yourself or hire a shop.

  • Parts: An OEM Subaru sensor costs $70–$130. Aftermarket (Denso, NTK) can be $30–$60. Always buy a known brand; cheap no-name sensors often fail quickly.
  • Labor: At a dealership, labor runs $100–$200 (0.5–1 hour book time). At an independent shop, $75–$150. DIY saves the labor cost entirely.
  • Total DIY cost: $30–$130 for the sensor plus a few dollars for a socket if you don’t have one.

Consider buying the sensor from a Subaru parts website or a reputable auto parts store. Check the recall/warranty history – some 2013–2015 FB engines had a technical service bulletin (TSB) regarding crank sensor issues; the updated part may be covered under warranty.

Preventative Maintenance and Tips

While the crankshaft position sensor is not a routine maintenance item, you can extend its life with these practices:

  • Keep the engine bay clean. Oil leaks from the valve cover gasket or cam carriers can contaminate the sensor connector. Fix any oil leaks promptly.
  • Inspect the sensor wiring harness whenever you change the serpentine belt or perform timing belt service (every 105,000 miles for EJ engines). Look for chafing near the belt path.
  • Consider replacing the sensor preemptively when doing major engine work (timing belt, water pump, head gaskets). The sensor is relatively cheap and easy to access at that point.
  • Use OEM or high-quality aftermarket sensors only. The engine management system is sensitive to signal quality. Cheap sensors may cause intermittent problems that are hard to diagnose.
  • Never apply sealant or gasket maker around the sensor’s O-ring. It is designed to seal without additional compound. Excess sealant can enter the engine oil system.

Frequently Asked Questions

Can I drive my Subaru Outback with a bad crankshaft position sensor?

No. If the sensor fails completely, the engine will not start. If it fails intermittently, the engine may stall without warning, creating a dangerous situation. Driving with a bad sensor can also cause misfires that damage the catalytic converter.

Will a bad crank sensor throw a code?

Usually, yes. The most common DTCs are P0335 (Crankshaft Position Sensor Circuit Malfunction), P0336 (Range/Performance), and P0339 (Intermittent). However, a failing sensor may not always set a code immediately, especially if it only drops signal under specific conditions (hot, high load).

Do I need to reset the ECU after replacing the sensor?

It’s a good practice. Disconnect the battery for 10 minutes, or use an OBD-II scanner to clear codes. The ECU will re-learn the crank position on the next start cycle.

Is the crankshaft position sensor the same for all Subaru Outback engine sizes?

No. The EJ25 (2.5L), EJ20 (2.0L), and FB25 (2.5L) all use different sensor part numbers. Also, the H6 (3.0L) and newer FA (2.4L turbo) engines have unique sensors. Always verify compatibility by your vehicle’s VIN or engine family.

How do I know if the sensor is actually bad vs. a wiring problem?

Test the sensor at the connector (see testing section). If the sensor passes resistance and voltage tests, the problem may be in the harness between the sensor and ECU. Check for continuity with a multimeter. A broken wire or corroded terminal can mimic a bad sensor.

External Resources

For further assistance, consult these helpful resources:

Remember to always refer to your vehicle’s service manual for torque specs, wiring diagrams, and model-specific details. Proper diagnosis prevents unnecessary parts replacement.

Conclusion

Locating the crankshaft position sensor in a Subaru Outback is straightforward once you know which engine generation you have and where to look. On EJ engines, it’s near the front pulley; on FB engines, it’s above the starter on the driver’s side. Symptoms of failure include no-start, stalling, and hard starting – especially when hot. Testing the sensor with a multimeter can confirm the diagnosis, and replacement is a manageable DIY job for most owners. By understanding the sensor’s role and location, you can keep your Outback running reliably and save money on unnecessary shop visits.

Always use quality parts and follow safety procedures. A properly functioning crankshaft position sensor is key to your Subaru’s engine timing and overall performance.