P2399 low

Direct Fuel Injection System Noise Sensor Circuit High

The P2399 code means the vehicle's onboard diagnostic system has detected: Direct Fuel Injection System Noise Sensor Circuit High. This is a low severity code.

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Keep driving?
Yes, but fix soon
DIY difficulty
hard
Estimated cost
$150 - $400 (parts and labor)
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Common Symptoms

  • Check Engine Light on
  • Audible ticking or knocking from fuel injectors
  • No significant driveability issues
  • Fuel injector noise louder than normal

Probable Causes (Ranked by Likelihood)

  • Failed fuel injection noise sensor Very High
  • Short to power in sensor wiring High
  • Excessive injector mechanical noise Moderate
  • PCM internal fault Low

Step-by-Step Diagnostic Procedure

  1. Retrieve P2399 and check freeze frame data

  2. Listen for abnormal injector noise with a stethoscope on each injector

  3. Test noise sensor signal output with a multimeter

  4. Inspect noise sensor wiring and connector for damage

Frequently Asked Questions

What does P2399 mean?

P2399 relates to the direct fuel injection noise monitoring system: Direct Fuel Injection System Noise Sensor Circuit High. Modern GDI engines use a noise sensor to monitor injector operation and combustion quality.

Can I drive with P2399?

Yes, this code usually does not affect driveability. The noise sensor monitors injector sound levels but its failure does not typically cause performance issues.

How much does it cost to fix P2399?

Expect $150 to $400 for noise sensor replacement and diagnosis. If an injector itself is the root cause, costs may be higher.

Sources

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

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