P0394 moderate

Camshaft Position Sensor B Circuit Intermittent (Bank 2)

The P0394 code means the vehicle's onboard diagnostic system has detected: Camshaft Position Sensor B Circuit Intermittent (Bank 2). This is a moderate severity code.

My Garage →
Keep driving?
Short distances only
DIY difficulty
moderate
Estimated cost
$60 - $350 (parts and labor)
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Common Symptoms

  • Intermittent Check Engine Light
  • Occasional rough running
  • Random hesitation
  • Engine may stall in rare cases

Probable Causes (Ranked by Likelihood)

  • Loose cam sensor B connector on Bank 2 Very High
  • Intermittent wire break High
  • Sensor failing under heat Moderate
  • Vibration fault Low

Step-by-Step Diagnostic Procedure

  1. Wiggle test on sensor connector while monitoring signal.

  2. Inspect connector pins.

  3. Check wiring at stress points.

  4. Test during hot and cold operation.

Frequently Asked Questions

How do I catch an intermittent cam sensor fault?

Drive with scan tool recording. Wiggle the connector and wiring while monitoring the cam sensor signal for dropouts.

Can heat cause intermittent cam sensor problems?

Yes, cam sensors can fail when hot and work when cold. This is a common failure pattern.

Should I replace the sensor preventively?

If you have intermittent cam sensor codes and the sensor is original with high mileage, proactive replacement is reasonable.

Sources

This page is built from documented references. Verify against your own service info before repair work.

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