P249E on 2011-2020 GMC Sierra 3500HD — Diesel Particulate Filter Pressure Sensor Intermittent/Erratic (Bank 1)
1 vehicles · 1 makes · $300-$2,000 repair
Most Reported On
P249E is an OBD-II diagnostic trouble code meaning “Diesel Particulate Filter Pressure Sensor Intermittent/Erratic (Bank 1).” Despite the label sometimes seen, the standard SAE definition of P249E is 'Closed Loop Reductant Injection Control At Limit – Flow Too High,' a diesel emissions code in the Selective Catalytic Reduction (SCR) system. The SCR system injects diesel exhaust fluid (DEF/AdBlue) into the exhaust to neutralize nitrogen oxides, and the engine computer adjusts the dosing in a closed loop using NOx sensors. This code sets when the system has to push DEF flow to its maximum correction limit to keep emissions in range, signaling the injection control can no longer compensate. It generally indicates a DEF delivery, fluid-quality, or sensor problem rather than a quick fix, and can lead to reduced power or warning countdowns if ignored. This code is most commonly reported on 2011-2020 GMC Sierra 3500HD, with repair costs ranging from $300 to $2,000.
Common Causes
Typical Repair Cost
Based on 1 documented vehicle-specific issues. Actual cost depends on root cause and vehicle.
Diagnostic Tools
To diagnose P249E, you'll need an OBD-II scanner. Here are our recommendations at every price point.
ANCEL AD310 Classic OBD-II Scanner
by ANCEL
A simple, affordable code reader that reads and clears check engine codes. Great for quick diagnostics on any OBD-II vehicle (1996+).
- Read & clear engine codes
- View freeze frame data
- I/M readiness status
- No batteries or app needed
BlueDriver Pro Bluetooth Scanner
by BlueDriver
Bluetooth OBD-II scanner with a free companion app. Provides enhanced diagnostics, smog readiness, and repair reports sourced from a database of verified fixes.
- Enhanced diagnostics (ABS, SRS, transmission)
- Repair Reports with verified fixes
- Smog check readiness
- Free app (iOS & Android)
LAUNCH CRP123X OBD-II Scanner
by LAUNCH
A professional-grade handheld scanner that reads all four major systems (engine, transmission, ABS, SRS) with live data streaming and graphing.
- Engine, transmission, ABS, SRS diagnostics
- Live data stream & graphing
- AutoVIN for vehicle identification
- Free lifetime updates via Wi-Fi
Autel MaxiCOM MK808S Diagnostic Tool
by Autel
Shop-level diagnostic tablet with bi-directional control, active tests, and full system coverage. Ideal for serious DIYers and small shops.
- All-system diagnostics (25+ modules)
- Bi-directional control & active tests
- Oil reset, EPB, BMS, TPMS, injector coding
- 7-inch touchscreen with Android OS
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FAQ
What does P249E mean?
P249E stands for "Diesel Particulate Filter Pressure Sensor Intermittent/Erratic (Bank 1)." Despite the label sometimes seen, the standard SAE definition of P249E is 'Closed Loop Reductant Injection Control At Limit – Flow Too High,' a diesel emissions code in the Selective Catalytic Reduction (SCR) system. The SCR system injects diesel exhaust fluid (DEF/AdBlue) into the exhaust to neutralize nitrogen oxides, and the engine computer adjusts the dosing in a closed loop using NOx sensors. This code sets when the system has to push DEF flow to its maximum correction limit to keep emissions in range, signaling the injection control can no longer compensate. It generally indicates a DEF delivery, fluid-quality, or sensor problem rather than a quick fix, and can lead to reduced power or warning countdowns if ignored.
What are the most common causes of P249E?
The most common causes of P249E are: Contaminated, diluted, or incorrect DEF/AdBlue fluid, Clogged or failing DEF injector/dosing valve, Faulty NOx sensor (upstream or downstream), Degraded or failed SCR catalyst, DEF line/tank leak or pump pressure fault, Exhaust leak upstream of the SCR system, Wiring or connector faults in the dosing/sensor circuits. The specific cause varies by vehicle.
How much does it cost to fix P249E?
Repair costs for P249E range from $300 to $2,000, depending on the vehicle and root cause.
Which vehicles are affected by P249E?
Au7o has documented P249E across 1 vehicle models from 1 manufacturers: GMC.
Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.