Mercedes GLA Problems: 12 Common Issues

While the Mercedes GLA is known to be a budget-orientated and small SUV, the Mercedes-Benz GLA range has more than its fair share of problems.

The Mercedes GLA suffers from collision prevention assist not functioning, start/stop not working as intended, transmissions problems, water pump failure, tire scrubbing, random battery drain, rear seat rattle, fuel door latch malfunction, cylinder head issue, PCV failure, guides on sunroof breaks, and windscreen cracking.

To help you make a more informed decision, we’ve broken down all of these common issues and looked at some Mercedes GLA recalls you need to be aware of (especially if you have one of these models).

12 Common Mercedes GLA Problems

1. Collision Warning System Not Functioning

The Mercedes GLA is not the only three-pointed star branded car with this issue; its bigger cousin, the GLE, also has problems with the “Collision Prevention Assist Plus” system.

The GLA has issues with the collision warning system because the sensors are too sensitive.

With just the installation of a number plate or protective vinyl, the system will throw out an error message on the gauge cluster reading, Collision Prevention Assist Plus inoperable.

This can take away features like automated braking to prevent a crash.

The fix is to take your GLA to Mercedes for a software recalibration.

2. Start/Stop Not Working As Intended

Yet again, another feature from Mercedes is compromised due to the system being too sensitive.

The start/stop system needs everything to be just right, even the outside temperature and humidity, which is a bit overkill.

As one of the GLA owners commented on the GLA Owners Forum:

“There are several things that affect the ECO Start/Stop function. Outside temp, inside temp, HVAC setting, mode of the GLA, and probably even the mood of the GLA! The latter probably has the most influence on how it actually functions!”

Disgruntled Mercedes GLA Owner

The more basic start/stop systems found in other car manufacturers will only take battery voltage and the vehicle’s angle on an uphill or downhill into consideration if the system doesn’t need to turn off the engine.

This feature is convenient as some GLA owners claim they save up to 2 miles per gallon (0.9 kilometers per liter) in city driving if the system works.

3. Transmission Problems

The GLA has two common issues with its transmission, the dreaded ‘Reverse not possible’ error, and the car shifts itself into neutral while driving.

With many GLA owners, the reverse not possible error is an empty threat with it being resolved after a restart, but some are less lucky.

Some owners experienced power loss and gears being skipped when shifting when the error appeared, and one owner even had to replace the entire transmission, which cost $10,500 to replace.

The car shifting into neutral while driving affected some GLA owners and caused them quite a fright behind the wheel.

The issue these affected was the software issue on the transmission control module.

4. Water Pump Failure

The GLA is one of many vehicles that utilize an electric water pump to regulate the engine’s water flow and temperature.

At around 31,000 miles (49,890 kilometers), many owners saw their water temperature gauge going into the red as the engine started overheating.

This was due to the electric water pump failing, and if driven long enough with the problem can cause engine damage and lead to the engine being rebuilt or replaced.

This was a common issue on the GLA250s, and the only fix was to replace the water pump with an eye-watering price of $2,700 at Mercedes.

5. Tire Scrubbing

Owners of the AMG versions of the GLA have an issue with low speed and turning sharply that the front tires start scrubbing.

This is when the Ackerman angle between the left and right front wheel doesn’t differ much, causing one tire to be dragged or pushed over the ground.

This can feel like a shudder or something loose on the car for many drivers, but it isn’t dangerous or destructive to the vehicle.

Here is an excellent explanation from one of the owners of a GLA45 AMG about this issue on the GLA Forum.

The fix is installing less performance-orientated tires to make it easier for them to slip at lower speeds, but it does take away from the car’s higher-speed handling.

6. Random Battery Drain

The GLA also suffers from a random parasitic battery drain, like many other modern vehicles fitted with many electronics; the Ford Edge is an excellent example of this problem.

Some owners had their auxiliary battery replaced up to 3 times in under two years, and the only job of the auxiliary battery was to power the electronics inside the cabin.

An update helped with the auxiliary battery’s lifespan; it must have disabled all electronics when the vehicle is turned off to make such a big difference.

On the GLA45 models, the main battery has a random parasitic draw, where the same owner had numerous issues where the battery dies in 2 days, or it can hold up to 2 weeks without driving.

7. Rear Seat Rattle

Nothing irritates occupants of a vehicle like an interior rattle, and the Mercedes GLA can have a terrible rattle that originates from the rear seats.

The latch that holds up the rear seat backrests has too much free play in the mechanism, causing the latch to rattle on the locking mechanism.

A quick fix is to use electrical tape to make the latch ring a bit thicker to ensure there is no free play when latched.

Another issue is a wiring harness underneath the rear seats that is not securely fastened down, which can cause intermittent rattles.

You can find a detailed picture of the said wiring harness here on the GLA Owners Forum.

8. Fuel Door Latch Malfunction

The Mercedes GLA does not have a cable-operated fuel door latch as older vehicles do but utilizes an electric latch.

There are issues with some of the GLAs: the electric latch stops working and won’t latch the fuel door or release it.

This can cause two issues, either someone can easily have access to your GLAs fuel filler and cause potential damage, or you cant open the fuel door to refill the fuel.

You can press an emergency fuel door release button, but it requires some disassembly of the trunk interior.

You will need to remove the left rear interior panel just behind the tail light and remove a square piece of foam inside the inner fender close to the tail light.

When the foam is removed, you will have sights on the small red latch release button that you can push to open the fuel door.

Here is a detailed explanation with a picture if you need it in a pinch.

9. Cylinder Head Issue

There were numerous Mercedes GLAs that were manufactured with bad-quality cylinder heads.

Many GLA owners were greeted with a check engine light on their instrument cluster at around 22,140 miles (35,631 kilometers).

When they took the vehicles in for an inspection, Mercedes workshops informed them that the cylinder head and some fuel injectors needed to be replaced.

Luckily this is a recall on the GLAs, so it had no cost to the owners.

10. PCV failure

On the first generation, 2014 to the 2020 year models,  there was an issue with the engine’s PCV valve, causing oil to build up in the engine’s intake.

The job of a PCV (Positive Crankcase Ventilation) valve is to remove unwanted gases from the crankcase of the engine.

With the GLA, there was some issue with the baffling inside the valve resulting in oil escaping into the intake.

While it might not sound like a terrible issue, the oil can degrade the plastic intake parts and also cause carbon buildup on the intake valves that can later result in poorer performance and gas mileage.

11. Guides On Sunroof Breaks

The GLA models with sunroofs have an issue with the rail guide shoe for the sunroof, it is made of plastic, and over time, it fatigues to the point where it breaks.

When it breaks, the sunroof does not seal watertight anymore, and any rain or snow will be able to enter the cabin through a slit made by the collapsed rail guide shoe.

The parts are not expensive at around $20 for two, but the labor is immense since the entire roof lining needs to be removed and the sunroof disassembled.

Here is the thread on the forum to better understand how these parts look and function.

12. Windscreen Cracking

Numerous brands have had issues with their vehicle windscreen cracking for no good or apparent reason, the Subaru Crosstrek suffers particularly with this issue, and the GLA is no exception.

Some Mercedes dealers stated that it was due to poor installation, and the glass was touching the vehicle’s body at a certain point, causing the glass to crack.

The only fix is to replace the windscreen and use an adequate amount of windscreen bonder silicone to ensure the windshield does not interfere with the vehicle’s body.

Recalls on the Mercedes Benz GLA

While recalls fix vehicle issues, there is still a chance that some cars never got fixed.

Either the owner did everything DIY or took it to a private mechanic who never knew about the recalls.

So it is advantageous for you as a potential buyer or owner of a Mercedes GLA to learn about these recalls. 

And if you already own a GLA, take your vehicle to a dedicated Mercedes-Benz dealer or trustworthy mechanic as soon as possible to rectify these problems.

2015 Recall

• 2015 GLA250, 250 4Matic vehicles are affected by poor welds on the intake and exhaust camshafts resulting in possible engine failure and damage.

2018 Recall

• 2015 to 2018 model-year vehicles were not equipped with adequate grounding on the electronics on the steering wheel, resulting in the driver’s front airbag not being correctly deployed.

2019 Recall

• 2013 to 2017 model-year vehicles have a software issue that can cause the date and time provided to the emergency call center through the eCall to differ from the actual time and relay inaccurate location info.

2021 Recalls

• 2015 to 2020 GLA250 vehicles equipped with the panoramic sunroof, the front panel between the sunroof and windshield may not be properly bonded and can detach from the car, causing a road hazard.
• 2016 to 2021 model-year vehicles have a software issue that can cause the date and time provided to the emergency call center through the eCall to differ from the actual time and relay inaccurate location info.
• 2019 to 2021 model-year vehicles, the multimedia system software can cause the display to remain black even after restart stay black and cause the rearview camera to display improperly.

2022 Recalls

• 2017 to 2022 model-year vehicles might have an error in the communication mobile SIM card software, causing network failures and resulting in an inability to use the eCall function.
• 2018 to 2021 model-year vehicles, due to a software error, the rearview camera may not display an image on the infotainment screen.

Source Kelly Blue Book

Final Thoughts On Mercedes GLA Problems

The significant problems with the Mercedes GLA are the failing water pump, the random battery draining issue, and the cylinder head that needs replacing.

The quality and reliability are average compared to other European brands in the Small Premium SUV segments like Audi and BMW.

The best thing to do if you own a Mercedes GLA is to take it to a Mercedes dealership and have them check for any recalls that haven’t been completed.

If you are in the market for a used Mercedes GLA, get a full vehicle history report and avoid any models with an outstanding recall.

Hopefully, you found this article helpful, and you can go to your next Mercedes GLA test drive knowing what to look out for.

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