Faulty or contaminated airflow sensor B; Damaged, corroded or loose wiring or connector at the sensor; Unmetered air leak after the sensor, such as a split intake hose or loose clamp; Blocked or restricted air filter or intake duct affecting the reading; Poor power supply or earth to the sensor, including a blown fuse or relay where fitted; Fault in the engine control unit.

P010A

Mass or Volume Air Flow Sensor B Circuit.

Generic
Powertrain
Generic code
Medium severity

How this code is built

P: SystemPowertrain
0: Defined bySAE, the same on every car
1: AreaFuel and air metering
0A: FaultThe specific fault in that area

What it means

P010A is the generic SAE J2012 code for a fault in the Mass or Volume Air Flow Sensor 'B' circuit. It is set when the engine control unit sees a signal from the second airflow sensor that is outside the expected electrical range or not in line with the other readings. 'B' usually refers to the second sensor on engines with two airflow sensors, such as dual intake paths or banks, but the exact location varies by model and engine.

Symptoms

Check engine light on
Poor or hesitant acceleration
Rough or unstable idle
Engine stalling or hard starting
Poor fuel economy
Engine running in a reduced power or limp mode

Possible causes

Faulty or contaminated airflow sensor Blikely
Damaged, corroded or loose wiring or connector at the sensorlikely
Unmetered air leak after the sensor, such as a split intake hose or loose clamppossible
Blocked or restricted air filter or intake duct affecting the readingpossible
Poor power supply or earth to the sensor, including a blown fuse or relay where fittedpossible
Fault in the engine control unitrare

How to diagnose

Read all stored codes and freeze frame data to see engine load, speed and temperature when the fault set, and check for related airflow or fuel trim codes
Identify which sensor is 'B' on this specific engine using the manufacturer's information, as the layout differs between models
Visually inspect the sensor, its connector, wiring and the intake pipework for damage, chafing, oil contamination, splits and loose clamps
Check the air filter and intake ducting for blockage or debris
Look at live data for both airflow sensors at idle and under load and compare them for plausibility against each other
Check the sensor supply voltage, earth and signal wire for continuity, shorts and voltage drop against the wiring diagram
Check fuel trims for signs of an air leak or incorrect airflow reading
Clear the code and road test to see if it returns, then recheck live data

How to fix

Repair or replace damaged wiring, terminals or the connector
Replace the airflow sensor if it is faulty or contaminated beyond cleaning with the manufacturer's recommended method
Repair intake leaks by replacing split hoses, seals or clamps
Replace a blocked air filter and clear any intake restriction
Restore the power supply or earth, including any blown fuse or faulty relay
Have the control unit tested and repaired or replaced only after all other causes are ruled out

Can I keep driving?

Medium severity

The car can usually be driven short distances, but fix it soon as poor running, stalling or limp mode may develop. Avoid heavy loads or long journeys if the engine is hesitating or stalling.

Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.