P0101 — Mass Airflow Circuit Range/Performance
Seen on: Heavy Truck
Mass Airflow Circuit Range/Performance. Common causes: MAF sensor reading out of range.
Your code rides along, so nearby mechanics see the fault before they quote you.
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.
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.