DURAMAX-P245C moderate Duramax ›

EGR Cooler Bypass Control Circuit Low

The DURAMAX-P245C (Duramax) diesel fault code means: EGR Cooler Bypass Control Circuit Low. This is a moderate severity code.

Unverified. We could not confirm this code's definition against freely available manufacturer documentation, so treat the meaning, severity and fix guidance on this page as unconfirmed. Check it against the manufacturer's service information for your exact model and serial range before acting on it. This page is kept out of search engines for that reason, and we are working through this family manual by manual.

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Keep driving?
Yes, with caution
DIY difficulty
intermediate
Estimated cost
$100-$2,500 depending on component
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What Are the Symptoms of DURAMAX-P245C?

  • Check Engine Light illuminated
  • Reduced engine performance
  • Limp mode or 'Service Engine' message
  • Rough idle or stalling (sensor-related)
  • Hard shift or slip (transmission codes)

What Causes DURAMAX-P245C? (Most Likely First)

  • EGR bypass valve actuator shorted low Very Likely
  • Wiring harness damage or connector corrosion Likely
  • Sensor end-of-life (high mileage engines) Possible
  • Control module internal fault Less Likely

Can I Still Drive with DURAMAX-P245C?

Yes, with caution. DURAMAX-P245C is rated moderate severity. Keep trips short and get it diagnosed soon rather than waiting for symptoms to worsen.

Frequently Asked Questions

What is P245C on a Duramax?

Duramax code P245C (EGR Cooler Bypass Control Circuit Low) is a moderate-severity diagnostic trouble code triggered by the engine control module when it detects a problem in the associated system. A bad 5V reference (P0642/P0643) will cascade into multiple unrelated sensor codes — always diagnose reference voltage first.

Is a Duramax P245C safe to drive?

Depends on severity — sensor codes usually drivable; PCM/transmission codes should be repaired before continued use.

How much does it cost to fix P245C on a Duramax?

Component repairs typically $100-$500. Control module replacement $800-$2,500.

Mechanics Guide Step-by-step diagnosis

How Do You Diagnose DURAMAX-P245C?

  1. Connect scan tool and capture freeze frame data showing when fault occurred

  2. Verify battery voltage and all PCM grounds are clean and tight

  3. Back-probe the suspect sensor / circuit with a DMM and compare to spec

  4. Inspect wiring harness for abrasion, chafing, or rodent damage

  5. After repair, clear code and drive a complete drive cycle to confirm fix

Sources 1

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

  • SAE J2012Diagnostic Trouble Code Definitions (defines P245C as a generic OBD-II code)

Which Vehicles Commonly Get DURAMAX-P245C?

  • 2007.5-2010 Chevy Silverado 2500/3500 HD 6.6L Duramax LMM
  • 2007.5-2010 GMC Sierra 2500/3500 HD 6.6L Duramax LMM
  • 2011-2016 Chevy Silverado 2500/3500 HD 6.6L Duramax LML
  • 2011-2016 GMC Sierra 2500/3500 HD 6.6L Duramax LML
  • 2017+ Chevy Silverado 2500/3500 HD 6.6L Duramax L5P
  • 2017+ GMC Sierra 2500/3500 HD 6.6L Duramax L5P

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