Transmission complaints by model year
Which parts fail
Components named in complaints (automatic and manual transmissions, CVT, axles, driveshaft, 4WD/AWD).
Mileage when the problem started
What owners report
Tl* the contact owns a 2009 Mercedes Benz ML320. The contact stated that while going approximately 5 MPH, the vehicle hesitated to shift into gear. The engine would rev and the vehicle would not respond. The contact then shifted into gear and the vehicle accelerated rapidly. The vehicle was taken to the dealer for inspection and the contact was informed that the failure was unable to be determined. The failure recurred several times later and the contact took the vehicle back to the dealer for another inspection where they informed the contact that the transmission module software needed to be updated. The vehicle was repaired but the failure recurred. The manufacturer was contacted but the contact had not received a response. The failure mileage was 45,000.
ML320 bluetec, randomly loses power. The power will be restored once the car is turned off and on again. Car has been to the dealer 7 times for repair of this one issue, including twice in a state with limited power. Dealer has done multiple software updates, turbo replacement, exhaust valves replacement and the issue is still present. On one of the last occasions this happened, the car lost power when trying to merge on to the hwy. This almost resulted in me being rear ended by a big rig. Luckily I was able to pull to the shoulder before I was rear ended. This is serious safety concern that needs to be addressed and rectified. As of 02/17/2014 this issue has not been corrected.
During braking the bas/ESP will come on causing no acceleration with the vehicle. This has happened 7 times in the last 3 days. Almost resulting in 2 accidents. Only tuning off and the the vehicle will temporally fix the issue.
I was driving a Mercedes-Benz ML320 on August 02, 2011. The car engine suddenly and completely shut down while I was driving. I got stuck on the inner lane of homestead rd, cupertino, ca. Fortunately I was not on a highway, otherwise, I don't know what would happen to me. I got my car towed to the Mercedes service. I was told that the crank sensor did not function properly. This costs me almost my life and $500. I think it's very dangerous to passengers if a car completely shut down while driving. Mercedes-Benz should have done a better job to prevent this from happening. To my point of view, this is a design flaw. I want to share this experience to all drivers with the same model and have them watch out the same situation May happen.
The car was in drive, it suddenly went into reverse, accelerated at tremendous speed down my driveway, up onto my property where it hit a tree - still in drive. Damage was in access of $16,000. Mercedes denied any defect or malfunction after their inspection. I have since learned that an almost identical accident was reported in 2000 to another car - same year, make & model as mine.
The consumer's Mercedes Benz m l 320 slowed down on its own. The consumer pulled over put the car in park and restarted it. After this incident the consumer parked in a mall parking lot. When she returned to the vehicle the shift lever would not move out of park. The vehicle was towed to a dealer. After the vehicle was picked up from the dealer it went into stick mode again. The SRS light illuminate on the dash. The vehicle was taken tot he dealer and when it was returned to the consumer the light was still on. The engine light illuminated and the front end vibrated.
Consumer was able to remove the key from ignition without the vehicle being in park. The consumer stated that she could shift the gear lever to all gears when the key was not in the ignition and engine in an off position. The vehicle rolled down the hill and ran over a mailbox damaging the vehicle and back while the gear lever was still in park. The rear seat belts does not retract and had to be manually pushed back into the mechanism.
Car was in park at the top of the driveway and rolled down my driveway down a hill and crashed into a tree to stop. The car maker sent an investigator out (after a month) who determined it was a defect in the transmission. (I am awaiting their report to me) car is not drivable.
Frequently asked questions
Which Mercedes-Benz ML320 years have transmission problems?
By NHTSA complaints, the 1999 (19), 2000 (12) and 1998 (10) model years. Transmission complaints make up 15% of all complaints for the 1999.
Is there a recall for Mercedes-Benz ML320 transmission problems?
No. NHTSA lists no transmission & drivetrain recall for any Mercedes-Benz ML320 model year. A widespread problem may still be covered by an extended warranty or a manufacturer service bulletin, so ask a dealer.
At what mileage do Mercedes-Benz ML320 transmission problems start?
Across all years, half of the complaints with a recorded mileage happened before about 61,000 miles; 30% happened before 50,000 miles.
What part fails most often?
Owners most often name the automatic transmission (31 mentions), followed by the transfer case (4-wheel drive) (5).
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.