Mileage when the problem started
Owner reports
Selected complaints filed with NHTSA by 2014 Mercedes-Benz CLA250 owners, lightly cleaned up (personal details are redacted by NHTSA).
Apparently the TPS (Throttle Position Sensor) which is built into the gas pedal on this 2014 MB CLA250 only lasts so long before it becomes defective under highway conditions and causes the vehicle to go into LIMP MODE. When full acceleration is necessary, the unit will work for perhaps a few months or less, and then continue to fail worse and more frequently with each attempt at full acceleration. At highway speeds, this is an essential feature in a 4-cylinder vehicle such as this one and without the necessary acceleration capability, can expose the driver to serious risk of collision with other on-coming vehicles traveling at highway speeds. …
Purchased a Mercedes cla 250c, and have had it became inoperative while driving on the beltway in washington d.c. Traffic, and more recently on the I-5 in san diego on 1/21/2017 during rain at speeds of 60+ MPH in heavy traffic. The vehicle decelerated quickly and lost speed. The console popped up flashing message 'pre-safe functions limited' on the console. The vehicle did not respond to accelerator. After coasting to the right shoulder I was hit, by a passing car, and the motorist kept on going.this had happened about 10 time, and I bought the vehicle new. Mercedes aware, yet they would not do anything because they said if the engine light is not on we cant diagnose it.
Multiple episodes of "pre-safe functions limited" occurring. When this message appears the car suddenly loses acceleration and you are not able to go above 30 MPH despite pressing on the gas pedal. This has occurred on normal 35-45 MPH streets but has happened multiple times on the highway when the car is going 65 MPH. Luckily, no motor vehicle accidents have occurred because of this issue. The car is able to accelerate and function normally after turning the engine off and on again. Have gone to Mercedes dealer multiple times to fix issue. The first time it occurred, Mercedes updated system software. Next they replaced vehicle sensors. Most recently they claimed the issue was due to oil pump failure. They replaced an oil control valve and oil pan. Four days after the repair I received the same "pre-safe functions limited message, my car stalled while I was going 40 MPH. …
Purchased my new CLA250 in September 2014. In August of 2015 my car suddenly stopped accelerating while driving 65mph on the nj garden state parkway!. The pre-safe warning was present on my dashboard. Luckily I was able to pull to the shoulder without causing an accident. This could have caused a major catastrophe killing me and others. I restarted the engine and drove to my destination making sure I stayed in the right lane on the parkway. It failed 2 more times while not on the highway but still a very dangerous situation. Took the car (which had 16,000 miles) to a Mercedes dealership when I returned and they performed a series of tests. They found a product technical support system update which involved updating the software. The failure did not occur again until nov. 2017. I almost got hit by a bus in philadelphia when my car decided to stop accelerating. …
Accelerating from an intersection after the light turned green, the engine began chugging and thumping. The check engine light came on immediately and the eco light started flashing . The engine stalled several times. We drove straight to the dealership with the car. At every intersection with a red light, it seemed as though the car would stall again. We did make it to the dealership. They kept it for three days, and determined that it was a defective manifold pressure sensor. This is the second time the manifold pressure sensor has had to be replaced. In the first episode on October 9th, 2014, the car died completely and the message "inoperable" appeared in the message screen. The car had to be towed in that time. Both instances required replacement of the same sensor and an update to the software.
See uploaded document protected auto issues for full story. Hennessy Buick, Mazda, GMC sold me a car 8/18/2017 unknowingly I discovered on 2/5/2019 that it had an illegal can blocker/switch (manipulates computer systems in car and tampers true mileage on car) installed in ignition switch. After obtaining emissions test 12/26/2018, several car failures began to happen while stationary at testing center. While in motion that day, several lights began to stop working. In January 2019, while driving the power steering failed causing me to be unsafe as I could not brake, gas or turn wheel. The block affected all items above, excluding wheels & visibility,but due to limitations I was only able to select 3
Car had no acceleration while driving in traffic on a major parkway. Vehicle inoperable pre safety features disabled flashed on the message center. Engine light also came on. Vehicle taken to be serviced and the accelerator module replaced. My car seemed okay until it happened 4 more times again while driving on a parkway. This occurred approximately 5 weeks after the car was "fixed". Same exact problem and message. Is mb waiting for someone to get killed? So many people having the same problem. I don't need to get in an accident. I thought I was buying a safe dependable vehicle with exceptional service. I should have kept my sonata. I'm really afraid to drive this car again once I get it back.
I have had the same issue as many others. I was driving my car down the highway in the left lane at 65 MPH. All of a sudden the speedometer dropped to 0 and I could not accelerate. I had to pull over to the side of the road and turn off the car. This first happened to me twice in December 2013. I took it into the dealership and they did several things to try and fix it. They told me they updated the software. I was scared to continue driving the car, but they assured me it wouldn't happen again. But, the same issue just happened to me again (June 2016). Why hasn't Mercedes done anything to fix this? I don't wan to drive a car that loses speed while I'm on a busy highway, it's not safe.
Vehicle became inoperative while driving on a highway. Happened twice today on speeds of 60+ MPH in heavy traffic. Vehicle decelerated quickly and lost speed, I was lucky to avoid collisions. The console popped up flashing message 'pre-safe functions limited' on the console. The vehicle did not respond to accelerator. After switching the ignition off and on again, the problem temporary disappeared, but then happened again. The vehicle is duly serviced and is still on warranty, there was no accidents or mechanical faults prior to date. Scary and very dangerous. Could have easily injured myself or someone else who would have hit the vehicle which suddenly becomes inoperative.
The car showed "pre-safe unavailable" and showed that the stability control off light on the dash. It went into "limp" mode just before a dangerous y shaped intersection where I was turning to the left leg of the y and the oncoming traffic was from the right side of the y. The car was almost totally unresponsive to throttle inputs, and as I had to slow down to see down the hill to the right side of the y, acceleration across the intersection was less than normal walking speed. Luckily, there was no traffic coming to the right or behind me. Dealer was unable to find the cause. I traded the car in for the next year model due to feeling unsafe driving it.
Acceleration complaints in other CLA250 years
Frequently asked questions
How common are acceleration problems on the 2014 Mercedes-Benz CLA250?
NHTSA has 36 complaints about the speed control & acceleration of the 2014 Mercedes-Benz CLA250, 20% of the model year's 179 complaints.
Is there a recall for 2014 Mercedes-Benz CLA250 acceleration problems?
No. NHTSA lists no speed control & acceleration recall for the 2014 Mercedes-Benz CLA250, though it has 6 recalls for other components. If the problem is widespread, a repair may still be covered by an extended warranty or a manufacturer service bulletin — ask a dealer.
At what mileage do 2014 Mercedes-Benz CLA250 acceleration problems start?
Half of the complaints with a recorded mileage happened before about 16,000 miles, and 79% before 25,000 miles.
Is it dangerous?
Owners linked 1 crash, 0 fires and 1 injury to speed control & acceleration problems on this model year. If you notice symptoms, have the car checked before driving further.
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.