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DTC code page

P0337: Crankshaft Position Sensor A Circuit Low Input

Quick answer: The ECU sees the primary crankshaft position signal voltage or amplitude too low to trust.

Drivers also search this fault as crank sensor low input, crankshaft position sensor low voltage, weak crank signal code.

Severity: high Family: powertrain Related paths: 10
Meaning

What P0337 usually means

P0337 means the crank sensor signal is present at too low a level or the ECU interprets it as a weak input. That can come from a failing sensor, poor wiring integrity, metal debris on the sensor tip, excessive gap, or low cranking conditions that leave the signal too weak to process reliably.

Fast triage

Start here before chasing parts

  • Scan first: save freeze-frame and pending codes before clearing anything.
  • Confirm the complaint: compare the stored code with current drivability symptoms.
  • Use context: trims, live data, and related codes usually narrow the fault faster than guesswork.
  • Work simplest to hardest: leaks, connectors, maintenance items, and known patterns before expensive components.
Initial checks

What to check first

  • Check battery voltage and cranking speed before blaming the sensor by itself.
  • Inspect the connector for corrosion, oil contamination, or pin fit problems.
  • Ask whether the no-start is worse hot, because weak crank signals often show themselves after heat soak.
Driving risk

Can you keep driving?

P0337 can leave the engine unable to restart, so avoid treating it like a harmless stored code.

High urgency: If symptoms are active, reduce driving and diagnose quickly before secondary damage builds.
Likely causes

Common causes behind this code

  • Weak or failing crankshaft position sensor output
  • High resistance, corrosion, or partial short in the signal circuit
  • Excessive air gap between sensor and tone ring
  • Low cranking voltage reducing signal quality on some designs
  • Contamination on the sensor tip or target wheel

Cause phrases often tied to this code: weak crank sensor, high resistance wiring, sensor gap too large, low cranking voltage, metal debris on sensor.

Diagnostic order

Suggested workflow

  1. Verify battery voltage and healthy cranking speed.
  2. Inspect the crank sensor connector, wiring, and mounting depth.
  3. Check scan data for RPM dropout or weak RPM response during cranking.
  4. Test or scope the sensor if wiring and basic power supply checks look normal.
  5. Inspect the tone ring and sensor tip for contamination or damage.
Avoid guesswork

Common mistakes

  • Skipping battery and cranking-voltage checks on a low-input fault.
  • Replacing the crank sensor without inspecting connector corrosion or wiring resistance.
  • Ignoring heat-related weak-signal complaints that only appear after restart.
Repair path

Practical fix guidance

  • Repair the weak-input cause first, whether it is voltage, wiring, sensor gap, or the sensor itself.
  • Verify reliable RPM signal on repeated starts before calling the repair complete.
Vehicle context

Affected brands in this MVP

Brand hubs help broaden internal linking now and can evolve into make-specific diagnostic notes later.

Aliases and common searches

English phrases tied to P0337

Useful when the driver knows the wording but not the exact DTC yet.

  • crank sensor low input
  • crankshaft position sensor low voltage
  • weak crank signal code
Related search intent

Queries this page can answer naturally

  • P0337 code meaning
  • what does P0337 mean
  • weak crank sensor signal
  • low input crankshaft sensor
FAQ

Quick questions about P0337

Can low battery voltage trigger P0337?

Yes on some vehicles, because weak cranking can leave the crank signal too small or noisy for the ECU to trust.

Is P0337 the same as a bad crank sensor?

Not always. Wiring, excessive sensor gap, or poor cranking conditions can create the same low-input result.

Why is P0337 often intermittent?

Because heat, vibration, and restart conditions can push a marginal signal below the ECU threshold only some of the time.