P0337 — Crankshaft Position Sensor A Circuit Low Input

Can I drive my vehicle with P0337?

Only briefly if the engine runs smoothly and does not stall. P0337 can interrupt crank-position sensing at any time, so continued driving is not recommended until the fault is repaired.

Does P0337 always mean the crank sensor is bad?

No. P0337 identifies a low input from the Sensor A circuit, and a failed sensor, shorted wire, corroded connector, poor ground, damaged harness, or reluctor defect may all cause it.

What should be checked first when P0337 is present?

Start with the sensor connector, wiring, power, and ground because these are common causes of a low crank-position input. Then verify the signal and check the reluctor if the electrical circuit is intact.

Will clearing P0337 solve the problem?

No. Clearing P0337 only resets the stored fault and monitors. The code will generally return until the sensor circuit, wiring, connector, or reluctor fault is properly repaired and verified.

The crankshaft position sensor tells your engine's computer exactly where the crank is rotating at any given moment. Without that signal, the ECU cannot synchronize fuel injection or spark timing, and the engine simply will not run. When the powertrain control module detects that the sensor's voltage has dropped below the minimum expected value—essentially reading near ground instead of producing a proper signal—it logs code P0337. This fault does not set off a single bad reading. The module must observe the abnormality repeat under specific operating conditions before it illuminates the check engine lamp. That is why the freeze frame data stored alongside P0337 is so useful: it records engine load, RPM, coolant temperature, and vehicle speed the instant the problem occurred, letting you recreate those exact conditions during testing.

"Circuit low" describes a condition where voltage on the crankshaft position sensor circuit stays abnormally low. Several things can cause this. A wire may have rubbed through its insulation and shorted to metal. The sensor may have lost its supply voltage entirely. A failed sensor can drag the signal down. In every case the result is the same: the ECU cannot see the crank's position, and engine operation suffers or stops altogether.

When P0337 sets, you will notice the tachometer stays flat during cranking, the check engine lamp turns on, and the engine may crank without starting or stall without warning while underway. Hot no-start conditions are particularly common with this fault. The severity is real—sudden stalling in traffic is dangerous and you should not continue driving with this code active.

Common Symptoms of P0337

• Tachometer does not respond while cranking the engine
• Check Engine Light illuminated
• Engine cranks normally but fails to start
• Engine stalls suddenly with no warning while driving
• Intermittent no-start condition that worsens after the engine is hot
• Possible rough running or decreased power if the engine manages to stay running

Most Likely Causes

Start with the most frequent culprits when troubleshooting P0337:

• Failed crankshaft position sensor pulling the signal low
• Supply voltage missing at the crankshaft position sensor connector
• Signal wire shorted to ground due to chafed or melted insulation
• Incorrect air gap between the sensor and the reluctor wheel
• Reluctor wheel damaged, bent, or missing teeth
• Sensor connector damaged, corroded, or making poor contact
• ECM internal processing fault (rare, consider last)

How to Diagnose P0337

Follow this sequence to isolate the root cause before replacing any parts:

1. Connect an OBD2 scanner and confirm P0337 is stored. Save the freeze frame data—it tells you engine load, RPM, temperature, and speed at the moment the fault was detected, so you can replicate those conditions during the drive cycle later.
2. Check for related diagnostic trouble codes. Accompanying codes often point directly to the underlying problem. Also search manufacturer technical service bulletins for your specific make and model—many P0xxx codes have known factory fixes or software updates available through the manufacturer website or NHTSA.
3. Perform a thorough visual inspection of the wiring harness and connectors associated with the crankshaft position sensor. Look for damaged insulation, broken wires, corrosion, moisture intrusion, and loose terminals.
4. Check for proper supply voltage at the sensor connector. Then measure resistance from the signal wire to ground—near-zero ohms confirms a short to ground somewhere in the harness.
5. Observe the RPM PID on your scanner while cranking the engine. No RPM reading confirms an open circuit, short, or failed sensor.
6. Remove and inspect the sensor physically. Check the reluctor wheel for damage, bent teeth, or metal debris that could interfere with the signal.
7. Clear the code and complete a full drive cycle that reproduces the freeze frame conditions. If P0337 does not return, the issue was likely intermittent. If it returns, the fault is still present.

Repair Options and Costs

Address the cheapest and most common causes first before spending money on major components:

• Repair sensor wiring: $80–$250
• Replace the crankshaft position sensor: $150–$400
• Replace the reluctor wheel: $400–$900

P0337 repair typically costs between $80 and $900 total, depending on which part is actually at fault. The majority of cases involve a failed sensor or damaged wiring rather than the reluctor wheel, which is the most expensive possible cause. A proper diagnosis before purchasing parts will keep your total bill on the lower end of that range in most situations.

Driving Safety Verdict

Stop driving the vehicle. P0337 indicates the engine control module has lost reliable data from the crankshaft position sensor. A failing crank sensor can cause sudden, unexpected stalling at any speed—with no warning and no ability to restart immediately. This creates a serious hazard for you, your passengers, and others on the road. Have the vehicle diagnosed and repaired before driving it again.

Related OBD2 codes

• P0300: Random/Multiple Cylinder Misfire Detected
• P0301: Cylinder 1 Misfire Detected
• P0302: Cylinder 2 Misfire Detected
• P0303: Cylinder 3 Misfire Detected
• P0304: Cylinder 4 Misfire Detected
• P0305: Cylinder 5 Misfire Detected