Engine

P0344 — Camshaft Position Sensor "A" Circuit Intermittent (Bank 1)

Severity: medium Drive with care, to a shop

What P0344 means

The camshaft position sensor tells the engine control module where the camshaft is, so it can time fuel injection and spark to the engine cycle. P0344 sets when the Bank 1 sensor "A" signal drops out or becomes erratic from time to time. Because the fault comes and goes, the engine may run fine one minute and stumble or stall the next.

Symptoms

  • Check Engine light on
  • Rough idle or intermittent misfires
  • Hard or long cranking before start
  • Hesitation and reduced power
  • Random stalling
  • Worse fuel economy

Possible causes

  1. Failing camshaft position sensor
  2. Damaged, broken or corroded wiring in the sensor circuit
  3. Loose, dirty or wet connector at the sensor
  4. Stretched timing chain or worn belt causing timing offset
  5. Oil contamination in the connector or on the sensor
  6. ECM input or software fault (rare)

How to diagnose

  1. Scan for codes and read freeze frame data to see when the fault occurred
  2. Inspect the sensor, connector and harness for chafing, oil, corrosion and a loose fit
  3. Wiggle the harness and connector with the engine running and watch for RPM or signal changes
  4. Test power, ground and signal wires with a multimeter or scope
  5. Compare the camshaft and crankshaft signals on an oscilloscope
  6. Check timing marks and chain slack or belt condition
  7. Look for other crankshaft or camshaft sensor codes
  8. If everything checks out, swap in a known-good sensor and clear the code

Common fixes

  • Replace the camshaft position sensor
  • Repair the damaged wiring and clean or replace the connector
  • Replace the timing chain or belt, tensioner and guides, and reset the timing
  • Reflash or replace the ECM (only after ruling out other causes)

Questions and answers

Can I drive with a P0344 code?

For a short, careful trip yes, but the engine could stall at any time, which is dangerous in traffic. Get it checked soon.

Why does P0344 come and go?

The code describes an intermittent signal loss, usually from a poor connection, damaged wire or a sensor that is failing. Vibration, heat or moisture can make the signal drop out.

Will replacing the sensor fix P0344?

Often, but check the connector and wiring first or the new sensor may set the same code. If timing is suspected, verify the timing marks and chain or belt condition.

This is general information about the code. The meaning can differ between makes and models: a scan tool and the repair manual for your car will show the exact cause.