Mercedes ML 250 Transmission Troubleshooting

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The Mercedes ML 250 may be one of the more modest vehicles from its range, yet it still manages to deliver all of the class and practicality expected of it. Features such as climate control, electrically adjustable front seats and an impressive audio system add extra convenience and elegance.

This diesel has impressive cruising capabilities and does an effective job of masking engine noise, becoming even quieter at higher speeds and offering impressive fuel economy on motorways.


The ML 250’s 2.1-liter four-cylinder twin-turbo diesel may not match up to its six-cylinder predecessor in terms of smoothness or performance, but its impressive torquey nature still manages to outdo any shortcomings in terms of acceleration. Even under light throttle applications on hills, speed builds effortlessly without exceeding 2000rpm; gear changes occur smoothly while response times remain speedy and refined.

The 250 is the sole ML in its new generation to utilize a four-cylinder diesel, making it one of the most fuel-efficient large premium SUVs on sale. Producing 201bhp and 369lb-ft of torque through its seven-speed automatic transmission system.

While not as impressive as the ML 350’s 7.0-second 0-62mph time, its extra cylinders do help shed weight and lower emissions while remaining more cost effective and capable of towing up to 6,600 pounds.


Transmission problems can have a devastating impact on your driving experience and should be repaired as quickly as possible to maintain optimal vehicle speed. Common symptoms of transmission malfunction are:

The 722.9 automatic transmission was first installed in Mercedes-Benz cars as early as 2004 and gradually replaced older 722.6 5-speed transmissions with these by 2008. While these transmissions offer many advantages over their predecessors, they do present their own set of problems.

One of the most frequent issues is a malfunctioning valve body that prevents hydraulic fluid from flowing properly and leads to shifting delays. While replacing either component could potentially fix this problem, more often it can be resolved simply by reading fault codes with an advanced diagnostic scanner like YOUCANIC.


The entry-level Mercedes-Benz ML 250 CDI boasts a 2.1-litre four-cylinder diesel engine producing 204bhp. While that might seem like a step down from its predecessors’ V6 diesels, this makes for an efficient and refined ride when coupled with the smooth auto box. Furthermore, AdBlue technology (which adds urea into exhaust to neutralise any harmful fumes) ensures it easily meets Euro emissions regulations.

All ML models come equipped with modern amenities, even the base model which starts at $50,725 including destination charges. A fully loaded ML 250 can tow 6,600 pounds when properly equipped. Options such as Lane Tracking and Parking Assist help make towing possible while 19-inch wheels, special leather upholstery and rear 115V household-style power outlets make up its options list. Antilock brakes, traction control and stability control as well as PreSafe (which detects an imminent front end collision) and active front head restraints make up its standard set-up.


If you can look past its lack of two cylinders and some amenities compared to its larger sibling, the Mercedes ML 250 BlueTEC makes for a superbly capable yet cost-effective luxury SUV. Not only is this diesel-powered model quiet, comfortable and fuel efficient; its diesel power also contributes towards fuel savings.

The ride quality can be stiff over speed bumps, but opens up nicely at highway speeds. In addition, Benz’s standard air suspension helps smooth out uneven roads for an enjoyable driving experience.

Though the ML 250’s gasoline V6 engine can get lively when needed, it may feel cumbersome when hauling lots of cargo or merging into fast-moving traffic. A diesel provides plenty of usable thrust while offering better fuel economy than estimated by the EPA (18 city/22 highway). Both more powerful ML 400 and AMG-badged ML 63 AMG models reach 60mph quickly enough.


The ML 250 Bluetec is powered by a 2.1-litre diesel paired with an auto gearbox. You can control its speed using steering-wheel paddles when necessary; otherwise it offers smooth and refined cruising around town with no diesel clatter or road noise entering its cabin – and is just as quiet at low speeds than its larger four-cylinder counterparts.

The Mercedes-Benz Intelligent Drive system utilizes various sensors to continuously monitor your surroundings, keeping an eye out for pedestrians, other drivers and road conditions as well as sudden changes to vehicle position or sudden shifts. Furthermore, cameras and radar aid in parking assistance by keeping an eye out for cars, obstacles or pedestrians within parking spaces.