Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This code means that the car's computer is having trouble with the sensor that measures how much air is going into the engine. It's like when you can't tell how much air is in a balloon because the balloon is not working right.
The Mass Air Flow (MAF) sensor measures the amount of air entering the engine, which is crucial for the engine control unit to balance and deliver the correct fuel mass to the engine. A P1140 code indicates a performance issue or range problem with this sensor.
The P1140 code is triggered when the Engine Control Module (ECM) detects a problem with the Mass Air Flow (MAF) sensor circuit. This could be due to an incorrect signal range or performance issue, affecting the air-fuel ratio and engine performance.
• Check Engine Light is on
• Poor fuel economy
• Rough idle
• Faulty MAF sensor
• Dirty or clogged air filter
• Vacuum leaks
MAF Sensor: Mass Air Flow Sensor, a device that measures the amount of air entering the engine.
ECM: Engine Control Module, the computer that controls engine functions.
• Scan the vehicle for codes and freeze frame data
• Inspect the MAF sensor and wiring for damage
• Check the air filter and intake system for obstructions
• Clean or replace the MAF sensor
• Replace the air filter
• Repair any vacuum leaks
• OBD-II scanner
• Multimeter
• Screwdriver set
$100 - $300
Moderate
• Nissan Altima
• Toyota Camry
• Honda Accord
• Regularly replace the air filter
• Keep the MAF sensor clean
• Inspect for vacuum leaks periodically
Sensor Issue
• Do not ignore the Check Engine Light
• Have the issue diagnosed and repaired promptly
Check with your vehicle manufacturer for any applicable warranties on the MAF sensor.
The P1140 code has been associated with MAF sensor issues in vehicles since the introduction of OBD-II systems in the mid-1990s.
Moderate – Addressing this issue promptly can prevent further engine performance problems.
Driving with a malfunctioning MAF sensor can lead to increased emissions and may not comply with local emissions regulations.
• Engine at operating temperature
• Vehicle in park or neutral
The MAF sensor is typically located between the air filter box and the throttle body in the engine bay.
Q: Can I drive with a P1140 code?
A: While you may be able to drive for a short period, it's best to have the issue diagnosed and repaired to avoid further damage.
Q: How often should I replace my air filter?
A: It's generally recommended to replace the air filter every 12,000 to 15,000 miles, but check your vehicle's manual for specifics.
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Fitment Required · Vehicle-fitment part
Relevant for airflow, fuel-trim, and intake-metering faults after confirming the sensor is actually at fault.
Airflow and fuel-trim codes can involve the mass air flow sensor after proper diagnosis.
Verify the sensor design and fitment for your exact vehicle.
View options on AmazonThese parts may be related to this fault category, but a code by itself does not confirm exact fitment or guarantee that replacing a part will solve the problem.