Symptoms of a bad crankshaft position sensor and replacement cost
How a failing crank sensor behaves, the OBD2 codes that confirm it, and 2026 replacement costs for parts and labor on common engines.
A failing crankshaft position sensor usually causes intermittent stalling, hard or no starts, a flashing check engine light during a misfire, or all three. The confirming OBD2 codes are P0335 through P0339. Average 2026 replacement cost runs $220 to $331 on common engines, more on luxury and tightly-packaged ones.
The crank sensor tells the ECM where the crankshaft is at any instant. The ECM uses that signal to time injection and ignition events. When the signal drops out or drifts, fuel and spark go to the wrong place at the wrong time, and the engine misbehaves.
Symptoms in order of how clearly they accuse the sensor
No-start with extended cranking
The engine cranks normally but does not fire. No spark, no injector pulse, or both. This is the textbook symptom of a fully dead crank sensor. If it cranks fine but never starts, you can almost always find a P0335 stored.
Intermittent stalling, especially at idle or under load
A heat-soaked or partially failed sensor cuts the signal momentarily, the engine dies, you restart it, and it runs fine again. Stalls in stop-and-go traffic on a hot day are the classic version. Some drivers learn to coast to the shoulder and wait three minutes for the sensor to cool down before it will restart.
Misfires, rough idle, flashing CEL
If the sensor is sending a noisy or drifting signal rather than nothing at all, the ECM still tries to run on it. Spark and injection events land slightly off, and you get misfires, rough idle, and a flashing check engine light. The misfire codes (P0300, P0301-P0308) come with the crank sensor code in the freeze frame.
Loss of power under acceleration, RPM cap
The ECM falls back to a default ignition map when the signal is unreliable. You will feel sluggish acceleration above about 3,000 RPM and sometimes a hard RPM ceiling.
Hard starting, particularly when warm
Crank sensor magnets can lose strength as they age and as they heat-soak. Cold starts are usually fine. Hot restarts after a 10 minute shopping stop are when it fails.
OBD2 codes that point at the crank sensor
| Code | Meaning |
|---|---|
| P0335 | Crankshaft position sensor A circuit malfunction |
| P0336 | Crank sensor A range/performance |
| P0337 | Crank sensor A low input |
| P0338 | Crank sensor A high input |
| P0339 | Crank sensor A intermittent |
| P0385-P0389 | Crank sensor B (some engines have two) |
P0300-series misfire codes alongside P0335 confirm a noisy signal causing real driveability problems, not just a wiring complaint.
Where it lives
The crankshaft position sensor sits next to a toothed reluctor wheel on the crankshaft, usually near the bottom of the engine. Exact location varies:
- Many GM and Ford V8s: behind the harmonic balancer or near the bell housing.
- Honda K-series and J-series: on the back of the block.
- Toyota 2GR, 1GR, 2AR: on the side of the block near the oil filter housing.
- Subaru FA/FB: low on the timing cover, awkward but accessible.
- BMW N20/N55: under the intake manifold, which adds labor time.
The harder it is to reach, the higher the labor bill.
2026 replacement cost
| Vehicle | Part | Labor | Total |
|---|---|---|---|
| Common domestic/import (Civic, Camry, F-150, Silverado) | $84 to $133 | $135 to $199 | $220 to $331 |
| Subaru, Mazda CX-5, midsize SUV | $90 to $180 | $150 to $250 | $240 to $430 |
| BMW, Audi, Mercedes (intake-off jobs) | $120 to $250 | $300 to $600 | $420 to $850 |
| Heavy-duty diesel (6.7 Cummins, 6.7 Power Stroke, 6.6 Duramax) | $80 to $200 | $200 to $500 | $280 to $700 |
OEM sensors typically last longer than the $20 boxes on eBay. NTK, Denso, Standard Motor Products, Bosch, and Delphi all make OE-quality aftermarket parts at reasonable prices. Avoid no-name brands. A cheap sensor can throw the same code again within months.
DIY notes
On many engines this is a one-bolt, one-connector job. On others it is buried. Before you commit:
- Confirm the diagnosis with a scanner that can read live engine RPM signal data. If the signal drops to zero during cranking, the sensor is dead.
- Buy the OEM-spec part with a matching connector. Aftermarket pigtails sometimes do not mate cleanly.
- Note the orientation. Some sensors have a specific air-gap to the reluctor and a built-in spacer that must stay in place.
Driving with a known crank sensor failure risks getting stranded. It is also the kind of failure that can leave you sitting at a green light. Replace it sooner rather than later.