DURAMAX-P2149 serious Duramax ›

Fuel Injector Group "B" Supply Voltage Circuit/Open

The DURAMAX-P2149 (Duramax) diesel fault code means: Fuel Injector Group "B" Supply Voltage Circuit/Open. This is a serious severity code.

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Keep driving?
Yes, with caution
DIY difficulty
intermediate
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What Are the Symptoms of DURAMAX-P2149?

  • Check Engine Light on
  • Misfire or rough running on several cylinders
  • Reduced power
  • Possible no start

What Causes DURAMAX-P2149? (Most Likely First)

  • Open or damaged injector supply wiring High
  • Loose or corroded connector or ground High
  • Injector driver or control module fault Moderate
  • Shorted injector on that group Low

Can I Still Drive with DURAMAX-P2149?

Yes, with caution. DURAMAX-P2149 is rated serious severity. Keep trips short and get it diagnosed soon rather than waiting for symptoms to worsen.

Common Fixes by Vehicle

What techs usually find when diagnosing DURAMAX-P2149 on specific platforms — tap a platform for the fix and the exact part:

2001-2016 GM 6.6L Duramax (all generations) Moderate DIY

Injector group B supply - sister code to P2146. Same root cause tree: FICM, wiring, or ground. Check both group A and group B codes together. If only group B, suspect the harness or a single injector pulling the bus down.

Labor: 1.0 hr
Common fix part FICM (Fuel Injector Control Module) View on Amazon→ Compare fitment at PartsGeek→

Frequently Asked Questions

What does P2149 mean on a Duramax?

P2149 means Fuel Injector Group "B" Supply Voltage Circuit/Open. The engine computer has detected an open or faulty supply voltage circuit for the group of injectors it calls group "B".

Is P2149 a Duramax-specific code?

No. P2149 is a generic OBD-II code defined by SAE J2012, so it means the same thing on any vehicle that sets it. The exact conditions GM uses to set it on its diesels are in GM service information.

Mechanics Guide Step-by-step diagnosis

How Do You Diagnose DURAMAX-P2149?

  1. Find which injectors make up group "B" on your engine in the service information.

  2. Check the supply circuit, connectors and grounds for that group.

  3. Check each injector in the group for a short before replacing the driver module.

Sources 1

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

  • SAE J2012Diagnostic Trouble Code Definitions (defines P2149 as a generic OBD-II code)

P2149 on Other Platforms

The same code ID appears across other engines, vehicles, and equipment. Diagnostic flow varies by platform — see the matching breakdown:

Gas / Automotive (OBD-II) Generic OBD-II definition for P2149

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