EN

Severity: Moderate Code type: Generic (all makes)

P0344 Code: Camshaft Position Sensor A Circuit Intermittent (Bank 1)

The bank 1 cam sensor signal keeps dropping out for short moments, which can cause random stalling.

At a glance

Severity: 3/5 – Moderate3/5

Severity: Moderate

Meaning
Camshaft Position Sensor A Circuit Intermittent (Bank 1)
System
Ignition & Misfire · Powertrain
Safe to drive?
With caution
Typical repair cost
$60–$800
DIY difficulty
Easy

The PCM counts the pulses from the camshaft position sensor against the crankshaft signal on every revolution. P0344 means the cam signal on bank 1 is present most of the time but disappears, doubles up or becomes erratic for brief moments. That distinguishes it from P0340, where the signal is missing, and from P0341, where the signal arrives at the wrong angle. Intermittent faults are almost always electrical or thermal: a loose terminal, a harness rubbing through, a sensor that cracks internally when hot, or electrical noise from ignition parts. The engine may run perfectly for days and then stumble or stall without warning, which makes this code more of a safety nuisance than its severity rating suggests.

Can I keep driving? The car usually drives, but it can stall or stumble suddenly, sometimes in traffic. Avoid highways and busy junctions until the fault has been found, and be prepared for a restart that takes longer than usual.

How to read P0344

How to read P0344P10233444
  1. P Powertrain
  2. 0 Generic (SAE)
  3. 3 Ignition / misfire
  4. 44 Specific fault

Symptoms

  • Random stalling, often when the engine is fully warm
  • Brief stumble or jerk while driving, then normal running
  • Longer cranking before the engine starts, especially after a hot soak
  • Tachometer needle dropping for a moment
  • Check engine light that comes and goes

Possible causes

Ranked by how often each cause is behind this code (editorial estimate).

  1. Loose, spread or oil-contaminated terminals in the cam sensor connector 26%
  2. Cam sensor failing intermittently when hot, from an internal crack or weak solder joint 24%
  3. Harness rubbing through near the exhaust, a bracket or a moving engine part 16%
  4. Unstable sensor supply or ground, such as a corroded ground or shared reference splice 12%
  5. Electrical noise from leaking ignition components or a faulty alternator 10%
  6. Sensor not seated properly, debris on its tip or a damaged tooth on the target wheel 8%
  7. PCM input fault 4%

Diagnosis step by step

Diagnostic flow: P03441Read the history and conditions2Check terminal fit in the connector3Wiggle-test while watching thesignal4Apply heat and cold to the sensor5Measure supply and ground under load6Rule out noise and mounting problems

  1. Read the history and conditions

    Note how often the code has set, the engine temperature and speed in the freeze frame, and whether the crank sensor intermittent code P0339 or a reference voltage code appears too. Several sensor codes at once point to a shared supply or ground, not the cam sensor itself.

    Tools: OBD-II scanner

  2. Check terminal fit in the connector

    Unplug the cam sensor and inspect for oil, green corrosion and bent pins. Slide a matching test terminal into each socket: it should drag lightly. A terminal that falls in with no resistance won't hold contact when the engine vibrates.

    Tools: Flashlight, Pliers

  3. Wiggle-test while watching the signal

    With the engine running, watch the cam signal on a scope or the cam sync status in live data while you flex the harness from the sensor back toward the PCM. A glitch or stumble at one spot identifies the damaged section.

    Tools: OBD-II scanner, Multimeter

  4. Apply heat and cold to the sensor

    Warm the sensor body gently with a heat gun while monitoring the signal, then cool it with freeze spray. A sensor that drops out as it heats and recovers when cooled has an internal fault and should be replaced.

    Tools: OBD-II scanner

  5. Measure supply and ground under load

    Back-probe with the engine running: the supply should be steady at the specified 5 or 12 volts, and the voltage drop on the ground should stay below about 0.1 volt. A supply that flickers when you wiggle the harness points upstream of the sensor.

    Tools: Multimeter

  6. Rule out noise and mounting problems

    Check that the sensor is fully seated and its tip is clean, and inspect ignition coils, plug boots and harness routing near the coils. With the engine running, AC ripple at the battery above roughly half a volt suggests a failing alternator diode that can corrupt sensor signals.

    Tools: Multimeter, Flashlight

Where the parts are

Ignition: coils and spark plugs per cylinder – P03441234567
Ignition: coils and spark plugs per cylinder
  1. 1Ignition coil
  2. 2Spark plug
  3. 3Fuel injector
  4. 4Camshaft sensor
  5. 5Crankshaft sensor
  6. 6Engine computer (ECM)
  7. 7Intake manifold

Repair options & costs

RepairDIY?Estimated cost
Clean and re-tension or replace connector terminals Yes $60–$200
Replace camshaft position sensor Yes $80–$300
Repair chafed harness section No $150–$450
Replace alternator or ignition components causing interference No $250–$800

Rough US estimates for parts and labor; shop rates vary by region. Not a quote.

Notes by brand

Field data

Ford 5 Ecosport, Focus Bev, Focus Rs
Dodge 2 Grand Caravan, Journey
Jeep 2 Wrangler, Wrangler Unlimited

Source: NHTSA Complaints API (US government open data), analyzed by DTC mention.

Emissions / smog test impact

Will fail

P0344 sets the check engine light, and an active MIL fails OBD-II emissions testing. Because the fault is intermittent, make sure it hasn't returned and that the monitors have completed before your test.

Frequently asked questions

Why does my engine stall only sometimes?

Because the cam signal is lost only for moments, often when heat, vibration or a bump disturbs a weak connection. Between those moments everything tests normal, which is exactly what makes intermittent codes hard to find.

Should I just replace the sensor?

It's often the cause and not expensive, but a loose connector terminal or rubbed wire is just as likely. Check the terminals first; otherwise a new sensor may seem to fix it for a few days until the fault comes back.

How is P0344 different from P0340?

P0340 means the PCM sees no usable cam signal at all. P0344 means the signal is mostly there but drops out or becomes erratic briefly, so wiring, connectors and heat-related faults are the prime suspects.

Can a bad alternator really cause a cam sensor code?

Yes. A failing alternator diode puts AC ripple onto the vehicle's electrical system, which can distort low-level sensor signals and make the PCM miss or miscount pulses.

Sources