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.
- Keep driving?
- Yes, with caution
- DIY difficulty
- intermediate
- Estimated cost
- $100-$2,500 depending on component
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View pilot availability →What Are the Symptoms of DURAMAX-P2146?
- 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-P2146? (Most Likely First)
- FICM / injector power supply fault (LB7-LMM) 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-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 hrFrequently Asked Questions
What is P2146 on a Duramax?
Duramax code P2146 (Fuel Injector Group A Supply Voltage Circuit/Open) is a serious-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 P2146 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 P2146 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-P2146?
Connect scan tool and capture freeze frame data showing when fault occurred
Verify battery voltage and all PCM grounds are clean and tight
Back-probe the suspect sensor / circuit with a DMM and compare to spec
Inspect wiring harness for abrasion, chafing, or rodent damage
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 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:
Which Vehicles Commonly Get DURAMAX-P2146?
- 2001-2004 Chevy Silverado 2500/3500 HD 6.6L Duramax LB7
- 2001-2004 GMC Sierra 2500/3500 HD 6.6L Duramax LB7
- 2004.5-2005 Chevy Silverado 2500/3500 HD 6.6L Duramax LLY
- 2004.5-2005 GMC Sierra 2500/3500 HD 6.6L Duramax LLY
- 2006-2007 Chevy Silverado 2500/3500 HD 6.6L Duramax LBZ
- 2006-2007 GMC Sierra 2500/3500 HD 6.6L Duramax LBZ
- 2007.5-2010 Chevy Silverado 2500/3500 HD 6.6L Duramax LMM
- 2007.5-2010 GMC Sierra 2500/3500 HD 6.6L Duramax LMM
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