2014 Mercedes-Benz ML350 Problems

What owners report

Owners of the 2014 ML350 most often describe the vehicle stalling or losing power, frequently traced to water collecting in the spare tire well and reaching the fuel pump control electronics, or to engine and wiring faults. Electrical complaints are the largest group, covering instrument cluster and battery drain problems, driver-assist warnings, and turn signals that quit mid-drive. Many reports come in at relatively low mileage, with engine complaints clustered around 16,000 miles and electrical ones nearer 43,000 miles.

1. 1
   Fuel system

   Stall or power loss after water in spare tire well

   • 16 complaints (24%)
   • median 47,000 mi at 6.8 yrs old (6 state mileage, few)
   • filed 2014–2025

   Complaints describe the engine shutting off or losing power while driving, sometimes with dashboard lights coming on and the vehicle unable to restart for a period. Several owners traced this to water accumulating in the spare tire wheel well, where it reaches the fuel pump control electronics. Some report the condition returned after the recall remedy was performed, with drain plugs or drainage repairs not keeping the well dry. Reported across a wide mileage range, from around 59,000 up to 185,000 miles, often after rain or in vehicles used in wet conditions.

   Recall 22V955000

   What to check: Ask whether recall 22V955000 was completed and lift the spare tire cover to check for water, dampness or rust in the wheel well. Confirm the drain plug is present and clear.

   2 excerpts from owner complaints in NHTSA records

   “As we were driving 50mph, the car stalled and lost all power. The dashboard lights all lit up and the car wouldn't start. I don't get unnerved easily and it was fairly intense not being able to move your car out of traffic. After about 5 mins, the car would start again only to stop a minute or so later. After taking the car to the dealer, the issue stemmed from the fuel pump electronics board getting wet in the spare tire wheel well where water was accumulating. …”

   NHTSA complaint #11700540, filed 2025-11

   “I bought my vehicle into Mercedes Benz for a recall related to water collection in spare tire well which can cause a fuel pump control malfunction, NHTSA recall # 22V955. A few days ago, my vehicle could not start and I found water in my spare tire well. My OBD scanner tells me it is related to the fuel pump. I informed Mercedes Benz and they would not fix it. Obviously the work performed did not correct the recall. I'm writing here hoping I can get connected to the right channel to get this resolved as my vehicle is currently unusable. Thanks. …”

   NHTSA complaint #11549073, filed 2023-10
2. 2
   Engine

   Engine stalling, misfires and wiring or sensor faults

   • 17 complaints (25%)
   • median 26,000 mi at 3.0 yrs old (5 state mileage, few)
   • 1 mention a crash, fire or injury
   • filed 2014–2025

   Owners describe the engine cutting out while driving, rough running or misfires, and check engine lights with codes such as P0016. Some complaints mention camshaft adjuster or timing component wear, oil leaks from seals and the oil cooler, and engine harness damage that required replacement. Dealers in some reports could not reproduce the problem, while others quoted major repairs. Many reports come in well under 20,000 miles, with others between roughly 26,000 and 108,000 miles.

   2 related service bulletins

   What to check: Have a pre-purchase inspection scan for stored engine codes and check for oil seepage around the cooler and seals. Ask for service records showing whether oil changes and any software updates were done.

   2 excerpts from owner complaints in NHTSA records

   “2014 ML350 shut off while driving in the fast lane of a major highway. I had taken the vehicle for service, then three wks later because the car was losing power. The dealership checked it over the next day and assured me the car was perfect and had found no problems. The next day the car shut-off on the highway. The car was towed to the dealership where they eventually discovered a defect in the car. I no longer feel safe driving this vehicle.”

   NHTSA complaint #10908813, filed 2016-09, 34,000 miles

   “I am writing in regards to my 2014 ML 350 Suv. The check engine light came on and upon taking it to the mercedes dealership, I was told the issue is that the camshaft adjusters have failed and need to be replaced. The cost quoted is over $11,000 to repair. Upon further investigation I found reports on multiple lawsuits for the Mercedes C series for the same year (2012-2014) that resulted also in a recall whereby customers were given a recall to replace at no charge the camshaft adjusters up to 120k miles. …”

   NHTSA complaint #11511621, filed 2023-03
3. 3
   Electrical system

   Driver-assist and turn signal warnings or dropouts

   • 8 complaints (12%)
   • median 115,000 mi at 7.6 yrs old (2 state mileage, few)
   • filed 2019–2026

   Owners report blind spot and lane departure warnings appearing intermittently, sometimes with messages about limited functionality, and turn signals that stop working for the rest of a drive and reset after restarting the engine. Some complaints link the assist faults to water intrusion or wiring damage. Dealers in some cases replaced sensors, but owners say the warnings returned. Mostly reported between about 60,000 and 170,000 miles, though some owners describe the warnings appearing soon after purchase.

   What to check: Test the turn signals, blind spot and lane assist on a test drive and look for warning messages at startup. Check for signs of water intrusion in the cargo and side areas.

   2 excerpts from owner complaints in NHTSA records

   “3 electrical related issues within a few months. 1. Blind spot and Lane Departure warning come on and off while driving. 2. Blind spot yellow light comes on the side mirrors while applying break 3. This week the turn signal periodically stop working and each time have to stop kill engine and start engine again to reset but reset only last for a while.”

   NHTSA complaint #11426314, filed 2021-07

   “After driving the car, the right/left turn signal switch fails to work (no signal is given both in the panel of the car and the external turn signal lights do not flash). However, the emergency flashers still work. I have searched the issue and found many occurrences on the Internet. Such a common issue should be a manufacturing quality issue and deserves a recall.”

   NHTSA complaint #11483939, filed 2022-09
4. 4
   Electrical system

   Instrument cluster, battery drain and SOS messages

   • 13 complaints (19%)
   • median 26,000 mi at 4.6 yrs old (3 state mileage, few)
   • filed 2015–2025

   Complaints describe the battery draining repeatedly and the instrument cluster staying lit after the vehicle is shut off, sometimes with an SOS service message showing. Owners report dealers diagnosing a failed cluster or communication module and recommending replacement. Others note that a software step was needed after module service before all functions worked. Reported mostly between roughly 24,000 and 60,000 miles, sometimes after a battery replacement or jump start.

   Recall 19V787000Recall 17V1770004 related service bulletins

   What to check: With the car off, confirm the cluster and interior lights go dark and that no SOS or service messages remain. Ask whether any telematics or cluster software updates were applied and whether the battery has been replaced.

   2 excerpts from owner complaints in NHTSA records

   “April 12th 20018 I got in my benz and started it and all the lights on the instrument cluster light up and should go of after a few seconds but the lights did not go of so I put the car in drive and the emergency brake will not release so I had to push really hard on the brake to stop the car I turned it of and waited a few seconds and strated it again so thai can reverse it back in the park spot however when I put the sun in reverse it started going forward and all the lights are still on and the emergency brake still will not release so I …”

   NHTSA complaint #11092179, filed 2018-05, 24,851 miles

   “I purchased my car used at the Mercedes dealership in Tyler Texas June 2023. I took all my savings and paid cash and was told that the car was impeccable shape and there were no current issues and all the service records were up to date. November 2023 is when everything started happening and my engine light came on. It was revealed to me by a service tech that I was sold the vehicle with an existing major oil leak /seals broke. Etc. SEE Attached invoices. I have endured driving down the road and my car just giving out and losing power steering. …”

   NHTSA complaint #11657305, filed 2025-04

Buying note. A 2014 ML350 is worth considering only after confirming that recall 22V955000 was completed and that the spare tire well stays dry, and after a scan for engine and air bag codes. Service history showing electrical module and software updates done at a dealer is a useful indicator of how well the vehicle has been looked after.

Summary written with AI from a sample of 60 NHTSA complaints for this model year (picked at random, with complaints that state a mileage and recent ones taken first), then checked automatically against the source records. Where a problem shows a complaint count, every complaint for this model year was matched with fixed keyword rules (written with AI and tested against the sample), and the mileage, age and repair figures are calculated from those complaints; owners' figures are as stated, not verified. Other counts refer to the sample. The excerpts come from NHTSA's public complaint records and are unverified; capitalisation is normalised, NHTSA staff notes are removed, and shortened text ends with “…”. Something wrong? Request a correction.