As you drive around town in your high-end Mercedes-Benz vehicle, you never expect anything to go wrong. That’s why it’s so surprising to see the Stop Vehicle Leave Engine Running message on the information screen. What does this mean and should you stop driving?
In this guide, we touch on the meaning behind this Mercedes warning message. We show you what causes it and give you tips to fix it. It might surprise you that the majority of potential problems aren’t that difficult to deal with. Plus, there’s a section of the most-asked questions with answers at the bottom.
What Does The Stop Vehicle Leave Engine Running Message Mean On A Mercedes Benz?
A malfunction on the Mercedes-Benz dash that says, “Stop the vehicle shift to P, leave the engine running,” means that there’s low battery voltage. However, the cause of the low voltage can be various things, forcing you to perform a complete diagnosis to figure out what’s wrong.
The Stop Vehicle Leave Engine Running alert can happen on any modern Mercedes from the model year 2015 and newer. It doesn’t matter if you drive a C300, C43 AMG, GLA, G-Class or E300.
If you leave the engine running for ten minutes, the message may reset automatically because the battery will have charged to its appropriate level. However, you still need to get to the heart of the issue if you want to prevent this from occurring again.
Causes Of Stop Vehicle Leave Engine Running Warning on Mercedes Benz
The root issue of this Mercedes-Benz warning is low voltage, but there are multiple things that can cause it. You may simply have a discharged battery or it could be bad. Additionally, a failing alternator or bad wiring can cause the same problems.
Here are the four most common reasons for this Mercedes warning message.
1. Discharged Battery
The automotive battery is responsible for starting the engine and running the electronics. This 12V battery gets recharged as the vehicle runs, thanks to the help of the alternator. However, if you accidentally leave the headlights on or you are running accessories without the engine on, the battery could discharge.
The battery can also discharge if you have stored the vehicle without installing it to a maintainer or trickle charger. If the car isn’t driven enough to keep the battery charged, it’s going to fail you at some point.
2. Bad Main or Auxiliary Battery
If the battery seems to fail even though you are driving enough, it could be old and in need of a replacement. Most car batteries only last three to five years, even under the best circumstances.
Most Mercedes Benz vehicles use two batteries, the main and the auxiliary battery. If any of these batteries fail, it could lead to this warning message which we will talk more about later in the article.
Typically, there are warning signs that the battery is dying. It will become harder to start the engine. Plus, the lights can become dimmer and the accessories may start acting erratically.
3. Bad Alternator
As we touched on earlier, the battery gets charged while driving because of the car alternator. If this part fails, the battery can’t be recharged. Many people don’t realize that the alternator has failed until they’ve replaced the battery and had the same result.
Most alternators will last more than 100,000 miles. You shouldn’t have to replace the alternator sooner than every seven years in the majority of cases.
4. Bad Wiring
The battery and alternator are all part of an electrical system that must be maintained. For starters, the battery terminals can become corroded, leading to a connection problem. Battery corrosion keeps the connection from being secure, causing all kinds of trouble with starting and running accessories.
Additionally, there are wires and connectors running from the alternator to the battery and the battery to the starter. If any of these connections fail, there will be voltage issues that could cause the Mercedes warning light.
How To Fix A Stop Vehicle Leave Engine Running Message On A Mercedes Benz
In most cases, the Stop Vehicle Leave Engine Running alert is nothing major and you don’t need to worry. If it’s related to the battery or charging system, the fix is straightforward. We need to start by charging the battery or replacing it. Then, we need to make sure it remains charged or contact a professional for more help.
Follow these steps if you plan to diagnose or fix the problem on your own.
1. Charge the Batteries
If the battery isn’t charged, you need to increase the voltage. When it’s completely dead, you may need to jumpstart the battery. After that, the message might appear until the battery has a full charge.
The best way to charge a car battery is to drive at highway speeds. Plan to drive at least twenty minutes a week on the highway to keep the battery charged.
Additionally, you can use a battery maintainer or trickle charger at home to keep it topped off. These are great options if you aren’t planning to drive the car for a while.
We recommend reading through your vehicle’s service manual before working with the batteries. It’s important to know how many batteries your vehicle has, where they are located and the proper techniques used to charge them.
2. Replace Batteries
If charging the battery doesn’t fix the problem or it keeps happening, you may need to replace it. Most auto parts stores will check the battery charge to see if it’s dead or you can test it with a multimeter.
As we talked about earlier, Mercedes Benz usually has two batteries – the main and the auxiliary battery. If any of these batteries fail, your vehicle can run on the good battery, but you will see this warning message on your dashboard. Therefore it’s important to check the health of both batteries.
3. Maintain/Charge the Batteries Often
As we’ve touched on before, it’s important to keep the batteries at a full charge. By driving, you won’t have trouble doing this, but you may need to get creative if you don’t do a lot of driving.
Here are some tips to keep your batteries at optimal levels.
- Keep the terminals free from corrosion. Use a baking soda/water solution and wire brush to clean off any corrosion as it occurs.
- Drive your car at least twenty minutes a week at highway speeds.
- Hook up a maintainer or trickle charger when you can’t take the car out for a longer drive.
- Physically inspect the battery often. If you notice any bulges or imperfections, replace the battery.
It isn’t difficult to keep the car battery in good condition. In fact, it only takes a few minutes of your time. On the other hand, if you kill the battery, you could get stranded in an inconvenient location, waiting for roadside assistance to jump your car.
4. Contact A Professional
If you have a good amount of mechanical expertise, working with the car battery will probably feel like second nature. After all, it’s one of the first components we learned to deal with when we started working on cars.
Still, it’s okay to reach out for help when you need it. If you can’t figure out why the battery keeps draining, there could be something running that shouldn’t. Parasitic drains can be difficult to hunt down and may require the help of a professional. In fact, there have been class action lawsuits about Mercedes vehicles because of these difficult problems. Find a trusted mechanic in your area that you can reach out to and fix these battery issues before they get worse.
Can I drive my Mercedes if it says stop vehicle leave engine running?
The best thing to do when you see this warning message is to follow the directions. Stop driving and leave the engine running. You want to put the car in Park and turn off any accessories that aren’t needed. Make sure you are pulled over in a safe place while you wait for the message to disappear.
How much does a Mercedes C300 battery cost?
A new battery may cost $75 to $350. However, these aren’t always easy to replace because the batteries aren’t that accessible in this model. If you can’t do it yourself, you may need to spend another $120 or more to have a Mercedes technician tackle the job.
Can I change a Mercedes battery by myself?
In the majority of Mercedes vehicles, it’s simple to replace the battery. However, high-performance models have a unique setup because of the smaller hood design. It can be difficult to find and replace the batteries on these cars, so you may need more help from a qualified mechanic.
Why does Mercedes have two batteries?
Many Mercedes models utilize a two battery design. One is the main starting battery found in the trunk of the vehicle, with a smaller one usually found under the hood. Because of the high electrical demand with some of the luxury models, two batteries are needed to supply energy.
No one wants to deal with a warning message on the dash. We know firsthand how stressful this predicament can be, even as experienced mechanics. However, the Stop Vehicle Leave Engine Running alert on your Mercedes-Benz may not be a big deal.
In many cases, the car battery simply needs to be recharged, which just takes a little time. Otherwise, you may need to replace the battery or alternator, but should be in good shape afterward. A complete diagnosis will help you hunt down the problem and get back on the road again without warning messages.