P0101 — Mass Airflow Circuit Range/Performance
What it means: Mass Airflow Circuit Range/Performance.
How serious / can you keep driving: Serious. Power derate likely — plan to stop soon.
Check first: Inspect air filter and housing for bypass leaks
Don't risk it — look up listed providers near you and give them this code when you call.
Listed providers nearest Sparks, NV
Closest first. Tell them P0101 and what the truck is doing. RoadService.app lists these providers and does not employ them or carry out the repair.
- 0.0 mi away — based in Sparks, NV · (775) 355-6884
- 0.0 mi away — based in Sparks, NV · (775) 356-7200
- 0.0 mi away — based in Sparks, NV · (775) 359-0550
Seen on: Heavy Truck
What P0101 means
Mass Airflow Circuit Range/Performance. Common causes: MAF sensor reading out of range.
How serious is it?
Serious. Power derate likely — plan to stop soon.
Most likely causes
- MAF sensor reading out of range
- Dirty sensor
- air filter bypassing
First moves (roadside)
- Inspect air filter and housing for bypass leaks
- clean MAF sensor with MAF cleaner spray
FAQ
Mass Airflow Circuit Range/Performance. Common causes: MAF sensor reading out of range.
Serious — Power derate likely — plan to stop soon.
The most common cause is: MAF sensor reading out of range. Other possibilities include Dirty sensor; air filter bypassing.
Power derate likely — plan to stop soon. When in doubt, get a qualified mobile diesel tech on the truck before continuing.
Related codes
Codes that commonly appear alongside P0101, or share the same subsystem.
- Engine Protection — Power Derate Active (SPN 1569 FMI 31)
- Intake Manifold (Charge Air) Temp — High (SPN 105 FMI 0)
- Turbo Boost Pressure — High / Overboost (SPN 1127 FMI 16)
- Boost pressure high (SPN 102 FMI 0)
- Boost sensor — voltage low (SPN 102 FMI 4)
- Intake manifold temp — voltage high (SPN 105 FMI 3)
- Intake manifold temp — voltage low (SPN 105 FMI 4)
- Injection control pressure low (HEUI — older engines) (SPN 164 FMI 1)
Same symptom: Low boost / low power
Other air-path codes that arrive as a truck that will not pull the hill it pulled yesterday.
- Turbo boost pressure high (SPN 1127 FMI 0) · Engine
- Turbo compressor inlet temp high voltage (SPN 1172 FMI 3) · Engine
- Turbo compressor inlet pressure — high voltage (SPN 1176 FMI 3) · Engine
- VGT actuator position — not responding (SPN 2795 FMI 7) · Engine
- VGT position — not responding (similar to 2795) (SPN 5571 FMI 7) · Engine
- Turbo turbine inlet temp — high voltage (SPN 5856 FMI 3) · Engine
Find a mechanic or related guides
General diagnostic guidance for diesel engines (Cummins, Detroit, PACCAR, Volvo, Mack and more). Not a substitute for a scan-tool diagnosis on your specific truck.