# P0344: Camshaft Position Sensor "A" Circuit Intermittent (Bank 1 or Single Sensor) **Verdict:** Drive to a shop this week Engine sensors - Generic OBD-II code, applies to all gasoline cars and light trucks sold in the US since 1996. - **Typical cost:** $100-$400 - **Urgency:** This week - **Most likely:** Connector, wiring or failing cam sensor - **DIY?:** Steps 1-3 ## Quick answer P0344 means the camshaft position signal for sensor "A" on bank 1 is dropping out now and then. The engine computer saw the signal disappear or turn erratic briefly before it came back. A loose or oil-soaked connector, chafed wiring, or a failing sensor are the usual causes, and the car may start slowly or stumble. ## What does P0344 mean? The camshaft position sensor reads a notched wheel or shaped lobes on the camshaft, which turns once for every two crankshaft turns. Its pulses tell the engine computer which cylinder is on its firing stroke, so it can fire injectors in sequence and, on many engines, time individual coils. On engines with variable valve timing, it also confirms that the camshaft is where it was commanded. P0344 is an intermittent code for camshaft sensor "A" on bank 1, or the only cam sensor. "A" usually means the intake camshaft, and bank 1 is the side with cylinder 1. The computer sets it when the cam signal drops out or becomes erratic for a short time while the crank sensor shows the engine turning. Because the fault comes and goes, the engine may run normally between episodes. Many engines can keep running on the crank signal alone, but restarts may take longer. ## What are the symptoms of P0344? - Check engine light on, sometimes with no other symptoms - Longer cranking before the engine starts - Occasional stumble, hesitation or rough idle - Stalling on some engines, especially at idle - Symptoms that come and go with engine heat or rough roads ## What causes P0344? Ranked from most to least likely. Check them in this order: the cheap, common causes first. 1. **Loose, corroded or oil-soaked connector** (most common). The cam sensor often sits on the cylinder head or timing cover, where a leaking valve cover gasket or sensor O-ring can let oil reach the connector. Oil and corrosion on the pins cause a contact that works most of the time but drops out with heat or vibration. Look for oil inside the plug and a broken lock tab. 2. **Chafed or damaged wiring** (common). The cam sensor harness runs across the top or front of the engine near the exhaust manifold, coil packs and accessory belts. Heat-hardened insulation can crack and rub through, and a partly broken wire may connect only some of the time. Rodent damage is also common on cars parked outdoors. The dropout often reproduces when the harness is flexed. 3. **Failing camshaft position sensor** (common). A sensor with internal damage can work when cold and drop out when hot, or cut out intermittently before failing completely. This is more common as engines age. A scope showing missing or weak pulses with good wiring confirms it. A quality replacement matters, since poor parts can bring the code back quickly. 4. **Low voltage or shared power supply fault** (less common). Many cam sensors are Hall-effect designs powered by a 5-volt or 12-volt feed from the engine computer that may also supply other sensors. A weak battery, poor ground, or another sensor shorting that shared feed can make the cam signal drop out. Other sensor codes stored at the same time point this way. ## How do you diagnose P0344? 1. Review freeze-frame data and look for other sensor codes that suggest a shared power supply problem. 2. Inspect the cam sensor connector for oil, corrosion and a broken lock, and the harness for rubbing or heat damage. 3. Wiggle-test the wiring while watching the cam signal or sync status on a scan tool or scope. 4. Check the sensor's power, ground and signal at the connector, and test the battery and charging system. 5. Clear the code and test-drive through several cold starts and a full warm-up to try to reproduce the fault. ## How do you fix P0344, and what does it cost? | Fix | Typical cost | What it involves | | --- | --- | --- | | Repair cam sensor connector or wiring | $100-$350 | Includes cleaning or replacing the connector and repairing chafed wire. | | Replace camshaft position sensor | $120-$350 | Usually a bolt-in sensor on the head or timing cover; replace the O-ring too. | | Fix oil leak at sensor or valve cover | $150-$400 | Stops oil from reaching the sensor and connector again. | Full price breakdowns: [camshaft position sensor replacement cost](/cost/camshaft-position-sensor-replacement). ## Is it safe to drive with P0344? > **Drive to a shop this week.** Usually drivable for short trips, but get it fixed soon. If the engine starts stalling or will not restart, stop driving it, because a lost cam signal can leave you stranded. ## Will P0344 fail an emissions test? P0344 with the check engine light on fails an OBD-based emissions test in most states. An intermittent fault may let the light go off between episodes, but the code can stay stored. On engines with variable valve timing, a bad cam signal can also set timing codes. After the repair, drive until readiness monitors complete. ## After the repair: clearing P0344 Clear the code and drive through the conditions that set it, including several cold starts and a long drive to full temperature. A scan tool should show steady cam signal or sync status with no dropouts. Because the fault is intermittent, the repair is proven when no pending P0344 appears after two weeks of normal driving. ## How to prevent P0344 - Replace the cam sensor O-ring and fix valve cover leaks before oil reaches the connector. - Keep the sensor harness clipped away from exhaust manifolds and ignition coils. - Change oil on schedule, since sludge and leaks around the head affect nearby sensors. - Keep battery terminals and engine grounds clean and tight to protect sensor power and signals. ## Codes often seen with P0344 - [P0340](/codes/p0340): Camshaft Position Sensor "A" Circuit (Bank 1 or Single Sensor) - [P0341](/codes/p0341): Camshaft Position Sensor "A" Circuit Range/Performance (Bank 1 or Single Sensor) - [P0345](/codes/p0345): Camshaft Position Sensor "A" Circuit (Bank 2) - [P0365](/codes/p0365): Camshaft Position Sensor "B" Circuit (Bank 1) - [P0016](/codes/p0016): Crankshaft Position - Camshaft Position Correlation (Bank 1 Sensor A) ## Frequently asked questions ### Can I drive with a P0344 code? Usually yes for short trips, since many engines can run on the crankshaft signal when the cam signal drops out. Starting may take longer and the engine may stumble. If it begins stalling or fails to restart, stop driving and get it checked to avoid being stranded. ### What is the difference between P0340 and P0344? P0340 means the cam sensor A circuit on bank 1 has a lasting fault, such as no signal at all, while P0344 means the signal is dropping out intermittently. P0344 more often points to a loose or oily connector or chafed wiring, though a failing sensor can cause either. ### How much does it cost to fix P0344? Most P0344 repairs cost $100 to $400 at an independent shop. A connector or wiring repair runs about $100 to $350, and a new cam sensor $120 to $350. Fixing an oil leak that soaked the connector adds roughly $150 to $400 depending on the gasket. ### Can oil in the connector cause P0344? Yes, oil leaking past a worn sensor O-ring or valve cover gasket can seep into the connector and interfere with the signal. The fault may come and go with heat. Clean or replace the connector, replace the O-ring or gasket, and the code often stops. ### Can a camshaft sensor cause stalling? Yes, on some engines a lost cam signal causes stalling, especially at idle or during restarts. Many engines keep running on the crank signal, but others shut down or will not restart until the signal returns. Repeated stalling with P0344 is a reason to get it fixed promptly. ### Can I replace a camshaft position sensor myself? Often yes, because many cam sensors are held by one bolt on the cylinder head or timing cover. Disconnect the battery, unplug the sensor, swap it with a new O-ring, and clear the code. Check the wiring and connector first, since they cause intermittent codes often. ### Can a weak battery cause P0344? It can contribute, because low voltage during cranking or a poor ground can disrupt sensor power and signal. If the code appears mainly during starts, test the battery and clean the terminals. Replacing the battery fixes it only if low voltage was the real cause. ### Is sensor A the intake or exhaust camshaft? On most engines with two camshafts per bank, sensor A is the intake camshaft and sensor B is the exhaust camshaft. Some makers use different names or locations, so check service information before buying a part. On single-cam engines, sensor A is simply the only cam sensor on that bank. ### Can P0344 cause variable valve timing codes? Yes, the computer uses the cam sensor to check where the camshaft actually is. An unstable cam signal can make it think timing is wrong and set codes such as P0011 or P0016. Fix the P0344 cause first, then clear and recheck any timing codes. ### Will P0344 pass inspection? No, P0344 with the check engine light on fails an OBD-based emissions test in most states. Clearing the code resets the readiness monitors, so testing right after will usually fail as not ready. Fix the fault and drive normally for several days before going for the test. ## Sources - [SAE J2012: Diagnostic Trouble Code Definitions](https://www.sae.org/standards/content/j2012_201812/) - [EPA: On-Board Diagnostics (OBD)](https://www.epa.gov/state-and-local-transportation/vehicle-emissions-board-diagnostics-obd) ## Other engine sensors codes - [P0327 Knock Sensor 1 Circuit Low (Bank 1 or Single Sensor)](https://diagxcar.com/codes/p0327) - [P0332 Knock Sensor 2 Circuit Low (Bank 2)](https://diagxcar.com/codes/p0332) - [P0335 Crankshaft Position Sensor "A" Circuit](https://diagxcar.com/codes/p0335) - [P0336 Crankshaft Position Sensor "A" Circuit Range/Performance](https://diagxcar.com/codes/p0336) - [P0339 Crankshaft Position Sensor "A" Circuit Intermittent](https://diagxcar.com/codes/p0339) - [P0340 Camshaft Position Sensor "A" Circuit (Bank 1 or Single Sensor)](https://diagxcar.com/codes/p0340) - [P0341 Camshaft Position Sensor "A" Circuit Range/Performance (Bank 1 or Single Sensor)](https://diagxcar.com/codes/p0341) - [P0345 Camshaft Position Sensor "A" Circuit (Bank 2)](https://diagxcar.com/codes/p0345) - [P0351 Ignition Coil "A" Primary/Secondary Circuit](https://diagxcar.com/codes/p0351) - [P0352 Ignition Coil "B" Primary/Secondary Circuit](https://diagxcar.com/codes/p0352) - [P0365 Camshaft Position Sensor "B" Circuit (Bank 1)](https://diagxcar.com/codes/p0365) ## Symptoms - [Why does my car stall while driving?](https://diagxcar.com/symptoms/car-stalls-while-driving) - [Why is my car idling rough?](https://diagxcar.com/symptoms/rough-idle) - [Why does my car hesitate when I accelerate?](https://diagxcar.com/symptoms/car-hesitates-when-accelerating) ## Repair costs - [Camshaft position sensor replacement cost](https://diagxcar.com/cost/camshaft-position-sensor-replacement): $120-$350 --- Source page: https://diagxcar.com/codes/p0344 Updated: 2026-11-03 General information, not a substitute for a qualified mechanic.