Product Details
The formidable Mercedes-Benz M120 6.0L V12 engine—powering the flagship W140 S600, C140 CL600, and R129 SL600—is an engineering masterpiece renowned for its turbine-smooth power delivery and dominance on the Autobahn. To achieve this symphonic performance, the ME engine management system relies entirely on precise data from the Mass Air Flow (MAF) Sensors. Because the massive M120 operates essentially as two independent inline-6 engines joined at the crankshaft, your vehicle utilizes two separate MAF sensors—one dedicated to each bank of cylinders.
Mounted in the intake tracts, these highly sensitive Bosch components continuously measure the exact volume, temperature, and density of the air entering your V12. The engine computer uses this critical data to calculate the precise amount of fuel to inject and to manage transmission shift points. However, over decades of driving, the delicate heated film elements inside these sensors become coated with microscopic dust particles and oily blow-by vapor. When an element becomes insulated by dirt or burns out entirely, it sends skewed data to the computer, instantly throwing off the air-fuel mixture for that entire side of the engine.
Common Signs of a Failing M120 Mass Air Flow Sensor:
"Half-Engine" Operation & Limp Mode: If the computer receives totally irrational data from one MAF, it may shut down fuel and spark to that entire bank of cylinders to protect the engine, resulting in a catastrophic loss of power and severe vibration.
ASR/ESP Warning Lights: On late-90s Mercedes V12s, a failing MAF frequently triggers the ASR (Acceleration Slip Regulation) light. The traction control system relies on accurate engine load data; when the data is erratic, the system disables itself.
Check Engine Light & Fuel Trim Codes: A failing MAF will trigger a Check Engine Light, typically accompanied by Bank 1 or Bank 2 specific codes indicating the system is running excessively rich or lean.
Rough Idle & Stalling: You may experience an erratic, hunting idle, a severe stumble when accelerating, or sudden stalling when coming to a stop.
ECS Tuning Recommends for M120 V12 Owners:
Since the V12 utilizes two completely separate intake tracts, if one MAF sensor has failed due to age and mileage, the second sensor is likely not far behind. We highly recommend replacing both MAF sensors simultaneously to ensure perfectly balanced power output and fuel trims across both cylinder banks.
Tech Tip: Never install brand-new MAF sensors without replacing your engine air filters. The most common cause of premature MAF failure is a dirty or deteriorating air filter that allows debris to sandblast the delicate hot-film element.
Essential Tools & Hardware for the Job
Replacing the MAF sensors on your classic V12 is a very accessible DIY, but it requires extreme cleanliness and the right tools to navigate the large intake boots. We highly recommend adding these items to your ECS Tuning cart before starting the repair:
Mann-Filter Engine Air Filter Set (ECS Part #: ES#2570081): (CRITICAL) You must replace both engine air filters simultaneously to ensure clean, unrestricted airflow to your brand-new MAF sensors.
Schwaben Flexible Hose Clamp Driver (ECS Part #: ES#2975694): The MAF sensors on the M120 are secured by large worm-gear hose clamps tucked into tight spaces near the firewall. This flexible driver easily bends around the intake components to loosen and tighten clamps without slipping and gouging the plastic housing.
CRC Mass Air Flow Sensor Cleaner (ECS Part #: ES#3035760): While your new sensors are perfectly clean, this is a great chemical to keep on the shelf for future 20,000-mile maintenance intervals to safely strip away oil and dust without damaging the sensitive plastics.
Uncompromising OE Bosch Quality (Part # 0280217509 / OE # 0000940848)
When dealing with the complex electronics of a classic Mercedes-Benz flagship V12, you should never compromise with cheap, inferior aftermarket sensors. The engine computer relies on incredibly precise micro-voltage readings to perfectly balance both sides of the engine; generic sensors often lack this exact calibration, resulting in returning Check Engine Lights, rough idling, and ruined fuel economy.
Bosch literally invented the hot-film mass air flow sensor. Manufactured in Germany to strict Original Equipment specifications, this direct-replacement Bosch MAF Sensor (replacing Mercedes-Benz OE numbers 0000940848 and A0000940848) delivers the exact factory fitment, thermal longevity, and precise airflow calibration your classic V12 requires. By choosing this OE Bosch replacement, you are skipping the heavy dealer markup while guaranteeing seamless integration, restoring the smooth, luxurious power your flagship Mercedes is famous for.
This Part Fits the Following Vehicles
| Make | Model | Submodel | Engine | Year | Chasis | Special Fitment Notes |
|---|---|---|---|---|---|---|
| Mercedes Benz | CL600 | Base | V12 6.0L | 1998 | 140.076 | Use vehicle selector to confirm fitment |
| Mercedes Benz | CL600 | Base | V12 6.0L | 1999 | 140.076 | Use vehicle selector to confirm fitment |
| Mercedes Benz | S600 | Base | V12 6.0L | 1995 | 140.057 | Use vehicle selector to confirm fitment |
| Mercedes Benz | S600 | Base | V12 6.0L | 1995 | 140.076 | Use vehicle selector to confirm fitment |
| Mercedes Benz | S600 | Base | V12 6.0L | 1996 | 140.057 | Use vehicle selector to confirm fitment |
| Mercedes Benz | S600 | Base | V12 6.0L | 1996 | 140.076 | Use vehicle selector to confirm fitment |
| Mercedes Benz | S600 | Base | V12 6.0L | 1997 | 140.057 | Use vehicle selector to confirm fitment |
| Mercedes Benz | S600 | Base | V12 6.0L | 1997 | 140.076 | Use vehicle selector to confirm fitment |
| Mercedes Benz | S600 | Base | V12 6.0L | 1998 | 140.057 | Use vehicle selector to confirm fitment |
| Mercedes Benz | S600 | Base | V12 6.0L 120.982 | 1999 | 140.057 | Use vehicle selector to confirm fitment |
| Mercedes Benz | SL600 | Base | V12 6.0L | 1995 | 129.076 | Use vehicle selector to confirm fitment |
| Mercedes Benz | SL600 | Base | V12 6.0L | 1996 | 129.076 | Use vehicle selector to confirm fitment |
| Mercedes Benz | SL600 | Base | V12 6.0L | 1997 | 129.076 | Use vehicle selector to confirm fitment |
| Mercedes Benz | SL600 | Base | V12 6.0L | 1998 | 129.076 | Use vehicle selector to confirm fitment |
| Mercedes Benz | SL600 | Base | V12 6.0L 120.983 | 1999 | 129.076 | Use vehicle selector to confirm fitment |
| Mercedes Benz | SL600 | Base | V12 6.0L 120.983 | 2000 | 129.076 | Use vehicle selector to confirm fitment |
| Mercedes Benz | SL600 | Base | V12 6.0L 120.983 | 2001 | 129.076 | Use vehicle selector to confirm fitment |
| Mercedes Benz | SL600 | Base | V12 6.0L 120.983 | 2002 | 129.076 | Use vehicle selector to confirm fitment |
This product is not eligible for Lifetime Replacement
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ECS Tuning will accept returns for unused products within 90 days of the ship date for a refund to the original payment method used. The customer is responsible for the return shipping costs and fees. If selecting to use a prepaid shipping label, the shipping cost will be deducted from the total refunded amount. All new/unused products must be new, unused and must be in the original packaging, including labeling, manuals, hardware, etc. Special order parts are non-refundable.
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Free Shipping On Orders $49 & Up
Items marked with a 'Free Shipping On Orders $49 and Up' logo may qualify for free standard economy ground shipping to the contiguous United States (48 states) for most orders with a value greater or equal to $49.00 USD. Oversized products and direct ship products are excluded from this offer unless otherwise noted.
Free Shipping
Items marked as 'Free Shipping' may qualify for free standard economy ground shipping to the contiguous United States (48 states). Oversized products and direct ship products are excluded from this offer unless otherwise noted.
The policies listed above are subject to change at any time without notice.
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Why You Should Shop From ECS Tuning
ECS Tuning stands out as more than an automotive parts supplier-it's a vibrant community fueled by a shared passion for cars. Born from the enthusiasm of car lovers, we offer an unmatched understanding and commitment to the automotive world, providing high-quality parts and accessories sourced from our own experiences. Our selection is meticulously crafted to meet the highest standards of performance, quality, and design, catering to both the latest trends and classic styles.
Our distinct advantage lies in our passionate team and comprehensive support, offering expert advice and seamless service from selection to installation. Shopping with ECS brings exclusive perks, including our Lifetime Replacement Guarantee and free shipping on orders over $49, enhancing the value of every purchase. As a central hub for car enthusiasts, ECS Tuning fosters a rich community where ideas and experiences flourish, transforming us from a mere supplier into a platform where automotive dreams come to life.
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At ECS Tuning, we understand that plans can change. That's why we offer a flexible cancellation policy for our customers. You may cancel your order at any time before you receive the shipment confirmation. This policy is designed to provide you with peace of mind and the flexibility to make adjustments to your purchases as needed. Should you decide to cancel your order, simply reach out to our customer service team, and we will assist you with the process swiftly and efficiently.
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