P249F on GMC
Diesel Particulate Filter Pressure Sensor Intermittent/Erratic (Bank 2)
P249F on GMC vehicles indicates diesel particulate filter pressure sensor intermittent/erratic (bank 2). Au7o has documented this code across 1 GMC model — most commonly on Canyon. This is a diesel emissions code. The diesel particulate filter (DPF) traps soot from the exhaust, and a pressure sensor measures the pressure difference across the filter so the computer knows how full it is and when to run a cleaning (regeneration) cycle. P249F means the DPF pressure sensor signal on Bank 2 is intermittent or erratic — the reading jumps around or cuts out unpredictably rather than staying steady. This can cause the computer to misjudge soot levels, trigger unnecessary or failed regenerations, and may put the engine into a reduced-power mode. Typical repair costs on GMC range from $200 to $3,500, depending on the specific model and root cause.
Common Causes of P249F
- •Faulty or aging DPF differential pressure sensor
- •Loose, cracked or kinked pressure sensor hoses/tubes
- •Soot, moisture or carbon clogging the sensor lines
- •Loose or intermittent electrical connector at the sensor
- •Chafed or partially broken sensor wiring
- •Corrosion or water intrusion in the connector
- •Faulty ECM/sensor reference signal (less common)
P249F on GMC by Model
GMC Canyon(1 issue)
- 2.8L Duramax DEF System Faults and DPF Regeneration Issues2016-2025
The 2016+ Canyon Duramax 2.8L LWN diesel uses DEF (Diesel Exhaust Fluid) injection and a DPF (Diesel Particulate Filter) as part of its SCR emissions system. Owners frequently report DEF quality/level sensor faults, DPF regeneration failures in stop-and-go use, DEF pump failures, and NOx sensor faults. Trucks used primarily for short trips often cannot complete DPF regeneration cycles, leading to DPF plugging and the truck going into reduced power mode. GM issued multiple TSBs on DEF sensor calibration and DPF regen procedures.
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View P249F across all makes →Frequently Asked Questions
What does P249F mean on GMC?▼
P249F stands for "Diesel Particulate Filter Pressure Sensor Intermittent/Erratic (Bank 2)." This is a diesel emissions code. The diesel particulate filter (DPF) traps soot from the exhaust, and a pressure sensor measures the pressure difference across the filter so the computer knows how full it is and when to run a cleaning (regeneration) cycle. P249F means the DPF pressure sensor signal on Bank 2 is intermittent or erratic — the reading jumps around or cuts out unpredictably rather than staying steady. This can cause the computer to misjudge soot levels, trigger unnecessary or failed regenerations, and may put the engine into a reduced-power mode. On GMC specifically, this code is documented across 1 model.
What causes P249F on GMC vehicles?▼
Common causes on GMC: Faulty or aging DPF differential pressure sensor, Loose, cracked or kinked pressure sensor hoses/tubes, Soot, moisture or carbon clogging the sensor lines, Loose or intermittent electrical connector at the sensor, Chafed or partially broken sensor wiring. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P249F on a GMC?▼
Repair costs on GMC range from $200 to $3,500, depending on the specific model and root cause.
Which GMC models have P249F documented?▼
Au7o has documented P249F on 1 GMC model: Canyon.