2014 Mercedes-Benz ML350 Electrical Problems

Vehicle: 2014 Mercedes-Benz ML350 VIN: [XXX] I have experienced repeated failures of the Blind Spot Assist / driver-assist system since purchasing this vehicle. When I first purchased the ML350 in Texas, the vehicle already showed warning messages (“Blind Spot Assist Inoperative / Pre-Safe Function Limited”). The dealer attempted repairs before delivery, but the defect persisted. After moving to New York, the problem continued. On June 26, 2023, I took the vehicle to The Automaster Mercedes-Benz in Shelburne, VT. Their diagnosis confirmed water intrusion into the blind spot radar sensors, consistent with Mercedes-Benz TSB LI54.71-P-056477. Both left and right sensors and wiring require replacement. This is a safety defect because Blind Spot Assist and Pre-Safe features are disabled without warning, increasing risk of collision when changing lanes. Many other owners have reported the same issue, and Mercedes has issued a TSB acknowledging the defect, but no recall has been provided. I request that NHTSA investigate this recurring safety problem and require Mercedes-Benz to provide coverage or a recall for affected vehicles. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ID

11688328

Incident

Oct 17, 2017

I purchased a used Mercedes-Benz from Freehold Mitsubishi in early 2024. Within hours, serious safety issues appeared, including a check engine light, cylinder misfire, EVAP leak, traction control failure, and blind spot assist malfunction. The vehicle’s ECM and wiring harness were later found damaged due to oil leaks and electrical shorts. Despite multiple repair attempts, the vehicle was returned in worse condition and remains unsafe to drive. I am reporting these issues due to their potential risk to vehicle safety.

NHTSA ID

11670372

Incident

Apr 24, 2025

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. The car has been sputtering and there have been misfires, fauled fuel injectors, coils, s and spark plugs, oil leaks, fuel pump leaking gasoline in the engine and smoke coming from the hood. I thought my car was going to start on fire it smelled like a hot electrical wires and gasoline. My nerves are frayed from this car because of how many times it has broke down. I have missed work because of the car, I'm behind on my home bills, I missed my airline flight to see my sick father, I have had to pay for rental cars, all due to this vehicle. I am very concerned for my safety in this vehicle and I would like the vehicle fixed at the expense of Mercedes or my money back. Thank you, [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ID

11657305

Incident

Nov 20, 2023

ML350 engine stalled while driving on an expressway and would not turn back on. ML350 needed to be towed where it was determined that water accumulated in the spare tire wheel well, leading to the fuel pump short circuiting. This is directly related to NHTSA campaign 22V955000. That recall repair was completed prior to this incident. Per the technician, the recall repair installed a water drain plug to prevent the water accumulation. This repair effectively failed - the drain plugs malfunctioned and were not allowing water to drain. MBUSA deny’s responsibility for the failing drain plug - stating that the trunk weatherstripping is the root cause, not the failing drain plug. This is an unacceptable response and worth of the recall being expanded. The fuel pump control unit can still short out if MBUSA’s poor excuse of a recall fix fails as it did with mine.

NHTSA ID

11598349

Incident

Jan 29, 2024

See attached document for complaint

NHTSA ID

11573953

Incident

Aug 14, 2023

Blind spot assists and turn signals go out without warning. This model should have been included in the previous recall for timing. Having the same issues as other recalled cars.

NHTSA ID

11540845

Incident

Aug 25, 2023

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. My car only has 83k and I am told by two independent mechanics that the camshaft adjuster should not be failing like this and that this has been an ongoing issue with Mercedes. The safety issue is that I am told by independent mechanics that what could happen over time is that I could be driving and the entire engine/power just shuts off. This could even happen at high speeds on the highway. The mercedes dealer tells me there is no safety issues that could result from camshaft adjuster problems which doesn't appear to be true as per the other independent mechanics. I request further investigation into this issue because as per the independent mechanics its the "same engine" as the 2012-2014 that are under the recall . I'm requesting a recall on this for my car that Mercedes pays for. This should not be failing especially in a car with only 83k on it . If the C series 2012-2014 received recall on this part then I also think my ML 350 should be covered. Mercedes customer service tells me they cannot pay for the repair, they said I could file complaint for recall through NHTSA Thank you .

NHTSA ID

11511621

Incident

Mar 3, 2023

Known defect with timing issues that give code P0016. All cars should be part of this recall regardless of mileage on a known defect. This repair is extremely expensive and wouldn’t be needed if built correctly.

NHTSA ID

11510655

Incident

Mar 1, 2023

The contact owns a 2014 Mercedes-Benz ML350. The contact stated that while at a stop light, the vehicle lost motive and electric power and stalled without warning. The contact restarted the vehicle, but the vehicle failed to remain running. The vehicle was towed to an independent mechanic and the contact was informed that water had intruded into the rear of the vehicle causing electrical failures. The vehicle was not repaired because the Insurance Company deemed the vehicle a total loss. The manufacturer was contacted but offered no assistance. The failure mileage was 60,000. The contact stated that the interior of the vehicle has to be dried out first in order to assess the damage to the electrical system. The contact noted the failure mileage was 60379.

NHTSA ID

11504527

Incident

Jan 3, 2023

Mileage

60,000 mi

After a weekend of incessant rain, while driving a short distance (10 minutes) , this low-mileage, well-maintained 8 year old SUV suddenly stalled, Engine appeared to have powered down and the yellow Engine light came up and pressing gas pedal didn't do anything. I was fortunately able to press the Power button once frantically and re-start it once more and pull over to the side but the car refused to power on thereafter. After investigations by the shops, it appears there was water leaking "through" the body of the vehicle and into the area below the interior of the car, short circuiting Fuel Driver and stalling the car (which they subsequently repaired after draining the water and replacing/re-programming the fuel pump driver) before handing it off for the leak identification work. The car was subsequently taken to a specialist shop to figure out the leak, and they are unable to identify any reasonable source of the water leak and insurance is so far claiming this is "wear and tear". In the course of the testing, the *same* issue happened again and the car stalled while driven by the shop personnel and they could hear the sound of water inside the cabin all the way up to the front. They are unable to identify the source(s) of the leak and at this point, the car has been unusable for over 4 weeks as Insurance continues to push back and the shop can't do the additional work to identify the source in the body without insurance approval. I made attempts to contact the manufacturer but their only available contact is their Customer Support (no email/chat option) who refused to discuss this as it didn't pertain to them directly and re-directed me to talk to my own insurance company. I even reached out via Twitter but got no response. This expensive luxury SUV is not just unreliable at this point but *dangerous* where there are mysterious water leaks under natural conditions like rain leading to car stalling while in motion.

NHTSA ID

11498332

Incident

Nov 14, 2022

55,000 Miles now Engine shuts off while driving and steering wheel locks engine light comes on, we have had this problem starting at about 30,000 miles. They first said it was sensors which we replaced several times thousands of dollars later still have problem. It is currently at dealer for a month now and they told us we need a whole engine harness replaced for $11,000 but can't be sure this is the problem. Has anyone else had these problems please contact me [XXX]. [XXX] IL INFORMATION Redacted PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6).

NHTSA ID

11483205

Incident

Sep 7, 2022

The oil fuel line is leaking on the engine this is currently a recall on my year and model suv

NHTSA ID

11466859

Incident

May 1, 2022

Other that other 2014 ml350 have a recall for oil leaking from the reserve. Seems like my vehicle is affected by this issue as well, oil leak when low

NHTSA ID

11454833

Incident

Feb 24, 2022

Instrument Cluster malfunction. Battery drained and replaced. 2.5 weeks later, the new battery drained. After the vehicle was jumpstarted, the instrument cluster remained on with SOS inoperable showing on the panel. The instrument cluster will not turn off, even after the vehicle has been turned off. So it continues to drain the battery. Mercedes has diagnosed the vehicle with a bad instrument cluster and says that it needs to be replaced. There were no warning signs before the malfunction. I drove it and parked it. Then two days later the battery was dead. 10.19.21 - took vehicle to Mercedes for a regular schedule B service 10.21.21 - vehicle battery was dead after trying to crank it. 10.22.21 - Mercedes sent tow truck to bring it back to them. The battery was replaced on 10.25.21 and I picked up the vehicle. 11.10.21 - Vehicle NEW battery was dead again. Mercedes sent tow truck. The tow truck driver jumpstarted the vehicle and couldn't get the vehicle into neutral. Then the SOS inoperable message appeared. Vehicle was towed to Mercedes and diagnosed the next day (11.11.21) with a bad instrument cluster. Apparently there are no new instrument clusters available in the world, according to Mercedes, they are on backorder. And I cannot get a loaner vehicle. So they'd like for me to be without a vehicle for the foreseeable future.

NHTSA ID

11440311

Incident

Nov 10, 2021

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 ID

11426314

Incident

Jul 24, 2021

TL* THE CONTACT OWNS A 2014 MERCEDES-BENZ ML350. THE CONTACT STATED THAT WHILE DRIVING VARIOUS SPEEDS, THE LANE ASSIST FEATURE FAILED. THE LANE ASSIST INOPERABLE WARNING LIGHT ILLUMINATED. THE FAILURE HAPPENED INTERMITTENTLY. MERCEDES-BENZ OF NOVI (39500 GRAND RIVER AVE, NOVI, MI 48375 (248) 426-9600) DIAGNOSED AND REPAIRED THE SENOR BUT THE FAILURE REOCCURRED. THE MANUFACTURER WAS MADE AWARE BUT WAS NOT ABLE TO HELP. THE FAILURE MILEAGE WAS 60,000.

NHTSA ID

11207568

Incident

May 2, 2017

Mileage

60,000 mi

CAR ENGINE LIGHT ON. TOOK TO SERVICE CENTER. REQUIRED SOFTWARE UPGRADE. COST $275. CAR HAS 26K MILES. THIS SHOULD NOT BE AN EXPENSE TO BUYER BUT SHOULD BE A WARRANTY ISSUE. VERY UNHAPPY WITH MERCEDES-BENZ AND UNLIKELY TO PURCHASE YOU VEHICLE IN THE FUTURE. ALSO, NO OBVIOUS INSTRUCTION FOR CHECKING OIL LEVEL. ANOTHER RUSE BY MERCEDES-BENZ TO WRING ADDITIONAL $$ OUT IF CONSUMERS.

NHTSA ID

11094095

Incident

May 16, 2018

Mileage

26,000 mi

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 KEEP PUSHING REALLY HARD ON THE BRAKES AND PUT THE SUN IN PARK AND CALL MERCEDES OF SARASOTA FL FOR THE SECOND TIME AFTER A SCARE LIKE THIS MERCEDES SAID THAT THE SUN WAS FINE . WELL AT THIS POINT I WAS FORCED TO GET RID OF MY 4 YEAR OLD SUV BECAUSE I DO NOT TRUST DRIVING IT NO MORE AN SUV THAT I FULLY PAID FOR AND WAS NOT EXPECTING TO HAD TO GET RID OF IT SO SOON .

NHTSA ID

11092179

Incident

Apr 12, 2018

Mileage

24,851 mi

VEHICLE MADE A RIGHT-HAND TURN UPHILL AND COMPLETELY SHUT OFF FOR 25 MINUTES; ENGINE AND ELECTRICAL COMPONENTS. REQUIRED TO MANUALLY HOLD IN THE BRAKE ON AN INCLINE UNTIL VEHICLE RESTARTED. DEALERSHIP CANNOT REPLICATE THE ISSUE AND IS RETURNING THE VEHICLE.

NHTSA ID

11056890

Incident

Dec 18, 2017

2014 MERCEDES-BENZ ML 350 CHECK ENGINE LIGHT ILLUMINATED AND ROUGH RUNNING. *MW THE CONSUMER STATED THE DOOR WOULD STICK, THE ELECTRONICS MODULE AND DUEL DOOR CENTRAL LOCK WERE REPLACED. *JB

NHTSA ID

10659515

Incident

Nov 18, 2013