12V Mass Air Flow Intake Sensor 8V21-12B579-AA AFH70M-83 1516668 30757655 38894 86298 AFH70M-109

Quality sensors are manufactured to meet or exceed original equipment specifications. Premium options contain the best materials and electronics found in OE systems and are 100% tested as a direct replacement.

Part number 8V21-12B579-AA is widely cross-referenced across multiple automotive brands and aftermarket manufacturers. The following cross-references have been identified:

Additional cross-reference numbers that have been associated with this part include:

• AFLS-1

• AFLS195

• AFH70-M83

• 30 757 655

• 1 516 668

• 1516668

• 30757655

• 86298

The 8V21-12B579-AA Mass Air Flow Sensor is designed for a wide range of vehicles across multiple brands, with applications spanning both petrol/gasoline and diesel engines.

Important Compatibility Note: The earlier 2.4 sensor (6C11-12B579-AA) features a square end, whereas the later 2.2 sensor (8V21-12B579-AA) has a curved end. These two sensors are not interchangeable despite similar part number formatting. Always verify the physical appearance and part number on your existing sensor before purchase.

Additional Note: While this sensor is compatible with Land Rover Defender 2.2  applications (matching LR part number LR019830), some sources indicate it may not be compatible with certain Defender 2.2 TD4 variants. Always verify fitment with your specific vehicle.

A failing or failed 8V21-12B579-AA Mass Air Flow Sensor can produce a range of noticeable driveability issues. The MAF sensor is responsible for measuring intake air mass so the ECM can determine proper fuel delivery. When this sensor provides inaccurate readings or fails completely, engine performance is directly affected.

Common OBD-II codes associated with MAF sensor failure include:

• P0100 – Mass Air Flow Circuit Malfunction

• P0101 – Mass Air Flow Circuit Range/Performance Problem

• P0102 – Mass Air Flow Circuit Low Input

• P0103 – Mass Air Flow Circuit High Input

1. Disconnect Test: A simple diagnostic method is to unplug the MAF sensor connector. If the engine idle or performance improves significantly with the sensor disconnected, the MAF sensor is likely faulty.

2. OBD-II Scan: Retrieve diagnostic trouble codes to confirm MAF-related faults.

3. Visual Inspection: Inspect the sensor element for damage or contamination.

4. Check for Air Intake Leaks: Before replacing the MAF sensor, check for simple air intake leaks, as they can cause identical symptoms.

5. Physical Inspection: Note that earlier 2.4 sensors feature a square end, while later 2.2 sensors have a curved end. If your vehicle has been modified or the sensor previously replaced, verify the physical appearance matches your application.

Note: Symptoms may appear intermittently. A MAF sensor can fail gradually, with performance deteriorating over time as the hot-film sensing element ages or becomes contaminated. The most common cause of MAF sensor failure is contamination of the sensing element by dirt and moisture.

When purchasing a replacement 8V21-12B579-AA Mass Air Flow Sensor, consider the following factors to ensure proper fitment, performance, and longevity.

Critical: This part number 8V21-12B579-AA has a specific physical appearance – a curved end. The earlier 2.4 sensor 6C11-12B579-AA has a square end and is not interchangeable. Small deviations in the part number, e.g., different index letters at the end, have a big impact on interoperability with your vehicle. Always compare the part number and product images with your old part before purchase.

The 8V21-12B579-AA sensor is used across a wide range of vehicles including Ford (Fiesta, Transit, Mondeo, Galaxy, S-MAX, Mustang, Edge, Explorer, EcoSport, Ranger, Taurus), Land Rover (Defender), Lincoln, and Citroën models. Always confirm your specific vehicle's year, make, model, engine size, and original part number before purchasing.

This sensor is used in both petrol/gasoline and diesel applications across various displacements:

• Petrol: 1.6L EcoBoost, 2.0L EcoBoost, 5.0L V8

• Diesel: 1.6 TDCi, 2.0 TDCi, 2.2 TDCi

Verify your engine code and fuel type before purchase.

This sensor features a 4-pin connector with male connector type. Terminal types include Bullet, Mini-Blade, and Blade & Bullet. Before ordering, verify that the plug configuration matches your vehicle's wiring harness connector.

While aftermarket alternatives may be available at lower price points, quality varies significantly. Quality sensors are:

• 100% tested as a direct replacement

• Manufactured to meet or exceed original equipment specifications

• Calibrated for accurate readings

• Made from high-quality materials for ultimate durability

Some premium aftermarket options are Made in Germany (Q+) and undergo strict quality tests, making them a perfect alternative to the original part.

Ensure the replacement is a hot-film type MAF sensor as specified for this application. Incorrect sensor types will not provide proper readings to the ECM.

• Location: The MAF sensor is located in the intake duct between the air filter and throttle body

• Quantity: One sensor per vehicle

• DIY Feasibility: Replacement is generally straightforward for mechanically inclined individuals

• Mounting Style: Bolt-On

• Caution: Handle the sensing element with care; contamination from dirt, moisture, or oil can cause premature failure

Before replacing the MAF sensor, confirm that it is the root cause of your vehicle's symptoms. Perform the disconnect test or consult a professional diagnostic scan. Other issues such as vacuum leaks, clogged air filters, or faulty oxygen sensors can produce similar symptoms.

Quality MAF sensors typically come with warranties. Some suppliers offer warranties ranging from 12 months to longer periods. Consider the warranty coverage when comparing options, as this can be an indicator of manufacturer confidence in product quality.

Purchase from reputable suppliers with positive customer feedback. Reviews often provide valuable insight into product quality and compatibility. Some suppliers offer 14-day return policies or money back guarantees.

The most common cause of MAF sensor failure is contamination of the sensing element by dirt and moisture. Ensure your air filter is replaced at recommended intervals to prevent premature sensor failure. Also check that the intake system is properly sealed to prevent unfiltered air from entering.

Check the supplier's return policy before purchase. Some suppliers offer 14-day return policies. Ensure you have the option to return the sensor if it does not fit your vehicle.