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P0340 Code: Camshaft Position Sensor A Circuit Malfunction

P0340 means the engine computer is not receiving a reliable camshaft position signal. Learn the common symptoms, causes, severity, and typical repair costs.

The P0340 code means the engine computer is not receiving a reliable camshaft position signal. It is stored when the engine computer sees a signal or operating condition outside the expected range.

Ignition and misfire codes mean the engine computer detected incomplete combustion or unreliable timing information. The right fix depends on live data, freeze-frame information, service history, and whether other codes are present.

Symptoms

  • Hard starting
  • Stalling
  • Rough idle
  • Loss of power
  • Poor fuel economy
  • Check engine light

Common Causes

  • Failed camshaft position sensor
  • Damaged wiring or connector
  • Timing chain or belt issue
  • Low oil level affecting variable valve timing
  • Reluctor wheel problem
  • ECM issue, less commonly

Severity

Moderate to high. A bad cam signal can affect starting, timing, and drivability.

Typical Repair Costs

$150 to $1,200+

  • The lower end usually covers inspection, cleaning, wiring repair, or a simple sensor replacement.
  • The higher end applies when parts are hard to access or when the code is caused by a larger mechanical, emissions, or transmission problem.
  • Always diagnose before replacing parts, because one code can be triggered by several related systems.

Frequently Asked Questions

What does code P0340 mean?

P0340 means the engine computer is not receiving a reliable camshaft position signal. The exact cause should be confirmed with diagnostic data before replacing parts.

Can I drive with a P0340 code?

It depends on symptoms. If the car runs poorly, overheats, stalls, shifts harshly, or the check engine light flashes, limit driving and diagnose it promptly.

What is the most common fix for P0340?

Common fixes include addressing failed camshaft position sensor, damaged wiring or connector, timing chain or belt issue, but testing is needed to avoid replacing the wrong part.

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