Credov

P0101 fault code: what it means

P0101: MAF sensor reading is outside what the engine computer expects for the conditions. Very common on high-km cars.

Engine and gearbox (powertrain) · Minor

Usual causes, most likely first

  1. dirty or oil-contaminated MAF sensor
  2. air leak between MAF and throttle body
  3. blocked air filter
  4. failed MAF sensor

P0101 by make

Audi

MAF sensor reading does not make sense. On 2.0T check for air leaks between the MAF and the turbo; on TDI it often points to a fuel or mechanical fault, not the MAF.

Usual causes: air leak between MAF and turbo inlet; faulty MAF sensor (G70); blocked air filter or exhaust restriction; wiring or earth fault

BMW

Air mass meter (MAF) reading out of range. BMW DMEs cross-check the MAF with other sensors, so an intake leak can set it too.

Usual causes: air leak between the MAF and the throttle; failed air mass meter (do not clean it); wiring or connector fault

Ford

Mass air flow (MAF) sensor range/performance: the measured air flow does not match what the engine expects.

Usual causes: dirty or failed MAF sensor; blocked air filter; air leak in the intake or boost pipes; MAF wiring or plug

GWM

Mass air flow sensor range/performance.

Usual causes: dirty or faulty MAF sensor; air leak after the MAF; blocked air filter

Isuzu

Mass air flow sensor range/performance. A dirty MAF on 4JJ1 causes flat spots and smoke.

Usual causes: dirty or faulty MAF sensor; air leak after the MAF; blocked air filter

Jeep

Mass air flow sensor range/performance.

Usual causes: dirty or faulty MAF sensor; air leak after the MAF; blocked air filter

LDV

Mass air flow sensor range/performance.

Usual causes: dirty or faulty MAF sensor; air leak after the MAF; blocked air filter

Mazda

SkyActiv-D: MAF sensor reading doesn't match expected airflow.

Usual causes: dirty or faulty MAF sensor; air leak or restriction between MAF and intake manifold; EGR system not working right; turbo fault

Mercedes-Benz

Mass air flow sensor reading out of range. On OM642 diesels often a leaking turbo inlet O-ring letting in unmetered air.

Usual causes: dirty or faulty MAF sensor; intake/turbo inlet O-ring leak (OM642); blocked air filter

Mitsubishi

Mass air flow sensor reading does not match engine load.

Usual causes: dirty or failing MAF sensor; air leak after the MAF (split intake boot); clogged air filter; wiring fault

Nissan

Mass airflow sensor reading does not make sense for engine load.

Usual causes: dirty MAF sensor; intake air leak after the MAF; dirty or ill-fitting air filter; MAF wiring or connector

Skoda

MAF sensor reading does not make sense. On 2.0T check for air leaks between the MAF and the turbo; on TDI it often points to a fuel or mechanical fault, not the MAF.

Usual causes: air leak between MAF and turbo inlet; faulty MAF sensor (G70); blocked air filter or exhaust restriction; wiring or earth fault

Subaru

Mass air flow sensor reading does not match what the ECU expects for the engine load.

Usual causes: dirty or failing MAF sensor; split intake boot or air leak after the MAF; clogged air filter; wiring or connector fault

Suzuki

Mass air flow sensor range/performance.

Usual causes: dirty or faulty MAF sensor; air leak after the sensor; blocked air filter

Volkswagen

MAF sensor reading does not make sense. On 2.0T check for air leaks between the MAF and the turbo; on TDI it often points to a fuel or mechanical fault, not the MAF.

Usual causes: air leak between MAF and turbo inlet; faulty MAF sensor (G70); blocked air filter or exhaust restriction; wiring or earth fault

Volvo

Mass air flow sensor range/performance. A common D5 cause of low power and smoke.

Usual causes: faulty or dirty MAF sensor; air leak after the MAF; blocked air filter

What the repair usually costs

Not sure what P0101 means on your car? Ask Credov.

Before you clear it

Write the code down or photograph the scanner first. A code that comes straight back after clearing points to a fault that is still there. A car whose codes were cleared just before you arrived may be hiding one: the scanner's readiness monitors show "not ready" for a while after codes are cleared.

Researched by Credov from manufacturer and workshop sources. A fault code points to where a fault may be; a workshop confirms it with a diagnosis. Browse all fault codes.