DURAMAX-P2146 serious Duramax ›

Fuel Injector Group "A" Supply Voltage Circuit/Open

The DURAMAX-P2146 (Duramax) diesel fault code means: Fuel Injector Group "A" 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-P2146?

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

What Causes DURAMAX-P2146? (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-P2146?

Yes, with caution. DURAMAX-P2146 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-P2146 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 A supply voltage - the FICM (Fuel Injector Control Module) or its ground is suspect. Check FICM mounting bolts for proper torque and clean ground; inspect the large FICM connector for water intrusion. If FICM output voltage is under 45V on a scope, replace the FICM.

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

Frequently Asked Questions

What does P2146 mean on a Duramax?

P2146 means Fuel Injector Group "A" Supply Voltage Circuit/Open. The engine computer has detected an open or faulty supply voltage circuit for the group of injectors it calls group "A".

Is P2146 a Duramax-specific code?

No. P2146 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-P2146?

  1. Find which injectors make up group "A" 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 P2146 as a generic OBD-II code)

P2146 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 P2146

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More Duramax codes → Diesel home All diesel codes Heavy-duty Guides

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