Mass or volume air flow circuit fault
The controller detected a fault involving the mass or volume air flow measurement circuit. This measurement helps determine engine air intake and fueling. The code names the monitored circuit, not a confirmed failed air flow sensor, and the electrical implementation depends on the vehicle.
Can I keep driving?
If the light is steady and the vehicle behaves normally, contact a shop for vehicle-specific urgency advice. If there is severe shaking, stalling, major power loss, a flashing light, smoke or a fuel smell, pull over safely and arrange assistance.
What does this code mean for your car?
The same code can need different checks depending on the model and engine. Enter your vehicle details to find relevant sources and checks.
Symptoms
- Uneven idle or stalling
- Hesitation or reduced power
- Changed fuel economy or only a check engine light
Possible causes
- 1Open circuit, short or poor connection in the air flow circuit
- 2Sensor supply or ground fault
- 3Damaged or contaminated air measurement element
- 4Intake path disturbance affecting measurement
These possibilities are not ranked by frequency and do not diagnose your vehicle.
Checks you can safely do yourself
Safe checks only: engine off and cold, car on level ground.
- Save all codes and any freeze-frame data your scanner displays before clearing or repairs.
- With the engine off and cool, visually check the intake duct and air filter housing for a split or displaced cover; do not touch the sensing element or spray it with cleaner.
- With the vehicle parked and the engine off and cool, look at accessible wiring and connectors without disconnecting anything; photograph visible damage for the shop.
When you need a shop
Have the shop test supply, ground and wiring, compare the air flow signal with other load data, and check intake integrity. It must use the voltage, frequency or communication test appropriate to this sensor before deciding on replacement.
How much does it cost?
A US repair estimate needs a diagnosis and a local shop quote.
We do not have a verified US repair quote for this fault. Request 2-3 itemized estimates after diagnosis; vehicle, parts and labor determine the cost.
Get 2-3 quotes
Investigate this code for my carFAQ
Can I keep driving with P0100?
If the light is steady and the vehicle behaves normally, contact a shop for vehicle-specific urgency advice. If there is severe shaking, stalling, major power loss, a flashing light, smoke or a fuel smell, pull over safely and arrange assistance.
What can cause this code?
Possibilities include open circuit, short or poor connection in the air flow circuit; sensor supply or ground fault; damaged or contaminated air measurement element; intake path disturbance affecting measurement. The code does not rank causes or identify a part that must be replaced.
Does clearing the code fix the fault?
No. Clearing the code does not repair its cause or prove the fault is absent. It can erase diagnostic data and reset readiness monitors. Even if the code does not reappear immediately, the repair needs verification using the tests appropriate to the vehicle.
What if this code appears during a pre-purchase check?
Arrange an independent professional inspection before buying, including stored data, readiness status and written diagnostic findings. Have the shop test supply, ground and wiring, compare the air flow signal with other load data, and check intake integrity. It must use the voltage, frequency or communication test appropriate to this sensor before deciding on replacement.
How much does repairing P0100 cost?
We do not have a verified US repair quote for this fault. Request 2-3 itemized estimates after diagnosis; vehicle, parts and labor determine the cost.