What Does P0344 Mean?
The ECM has detected an intermittent signal from the camshaft position sensor A on Bank 1, meaning the signal drops out, becomes erratic, or produces unexpected pulses during operation. This is often a thermal or vibration-induced fault where the sensor or wiring functions normally when cold but fails when the engine reaches operating temperature or during heavy vibration. Intermittent CMP faults can cause random misfires, momentary stalling, and inconsistent idle quality.
Common Causes
35%
Loose or intermittent connection at the CMP sensor connector due to worn terminal tension or oil contamination
30%
Camshaft position sensor A (Bank 1) failing under thermal stress with internal cracking of the Hall-effect element
20%
Intermittent break in CMP sensor wiring harness caused by vibration fatigue near harness clamps or routing points
15%
Excessive camshaft endplay or worn cam bearing causing sensor-to-reluctor air gap variation beyond specification
Diagnostic Steps
1
With the engine running, perform a wiggle test on the CMP sensor connector and along the wiring harness while monitoring the CMP signal on a labscope. A signal dropout during wiggling isolates the fault to that section.
2
Remove the CMP sensor and inspect the tip for metallic debris buildup, cracks, or heat damage. Clean the sensor tip and inspect the reluctor wheel teeth through the sensor bore for damage, missing teeth, or excessive debris.
3
Measure the CMP sensor air gap with a feeler gauge (typical spec 0.5-1.5mm). Excessive gap from cam bearing wear will cause intermittent signal loss at lower RPMs.
4
Perform a thermal test by heating the sensor and connector area with a heat gun while monitoring the signal. Intermittent sensors will commonly fail between 180-220°F.
5
Check for proper sensor mounting bolt torque and ensure the sensor is fully seated in its bore. A loose sensor can vibrate and cause intermittent contact with the reluctor.
Estimated Repair Cost
$80 - $400
Parts + labor, varies by vehicle and location
The ECM has detected an intermittent signal from the camshaft position sensor A on Bank 1, meaning the signal drops out, becomes erratic, or produces unexpected pulses during operation. This is often a thermal or vibration-induced fault where the sensor or wiring functions normally when cold but fai...
The most common cause of P0344 (Camshaft Position Sensor A Circuit Intermittent (Bank 1)) is: Loose or intermittent connection at the CMP sensor connector due to worn terminal tension or oil contamination
Typical repair costs for P0344 range from $80 to $400, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Intermittent CMP signal loss can cause random stalling without warning, particularly dangerous in traffic or at highway speeds. Prompt repair is recommended to prevent unexpected loss of engine power.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P0344 to identify the root cause.
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Quick Info
Category
Powertrain
System
Engine Timing / Variable Valve Timing
Difficulty
Type
Generic (SAE)
Recommended Tools
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