Mercedes CLS-Class Wont Start? Here’s Quick Solutions to Most Common Problems

Intro

As a skilled mechanic with over two decades of experience, I’ve helped plenty of people battling when their Mercedes CLS-Class Won’t Start. And I’ll be straight with you, not being able to start your car when you need to drive is incredibly bothersome.

But keep your chin up, you’ve come to the right place, no need to keep googling searches like “difficulty starting Mercedes“, I got you covered. My name’s Robby, a certified auto mechanic with over two decades of experience, and in this article, I’ll outline the most common explanations for why your CLS-Class won’t start. I’ll cover all the commonplace offenders so you can diagnose what’s going on, plus what to do to resolve each particular problem. Drawing on my 20 years of firsthand experience, I’ll offer practical repair advice to get your Mercedes CLS-Class fire up and moving ASAP!

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Why Won’t My a Mercedes Start?

Mercedes CLS-Class wont start

Before we dive into the list of possible faults and fixes, it’s vital to first gain an understanding of the central issue. When you climb into your Mercedes CLS-Class and realize “it won’t start!”, there could be a number of things causing the troubles. Perhaps the engine isn’t cranking at all, or possibly it’s turning over partially yet not igniting. Or you might hear clicking when you try to start it, but sadly no ignition occurs. Each scenario can indicate different problems under the hood.

Common Reasons Why Your Mercedes CLS-Class Won’t Start

There are a host of culprits as to why your CLS-Class won’t fire up. Typical causes cover a dead or weak battery, defective alternator, starter motor issues, fuel system problems, plus electrical or wiring issues. Every one of these concerns can show up differently, needing specific methods of diagnosis and repair to get you driving again pronto. All of which, we’ll delve into.

Symptoms of a Mercedes CLS-Class That Won’t Start

Recognizing these warning signs will lead you to the main cause. For instance, when you turn the key and you hear it turning over yet no start up, it often signifies a problem with either fuel delivery or ignition issues.

Analysis of The Reasons Why Your Mercedes CLS-Class Won’t Start

The initial move in fixing the no-start hassle is identifying the precise source of the issue. So let’s examine the most frequent explanations for the CLS-Class not starting when you turn the key.

Battery Issues in a Mercedes CLS-Class

car wont start but battery is good
Image Credit: MechanicAnswer.com

In the vast majority of situations, the most common reason a Mercedes CLS-Class won’t start comes down to issues with the battery. Specifically, a weak or dead battery prevents the engine from turning over. The car’s battery provides the required power to ignite the engine and energize all your vehicle’s electrical components. Signals of a failing battery entail sluggish or strained cranking, dim headlights, or a warning light aglow on the dash. A battery charger can recharge a drained battery if you don’t have the help of another vehicle to jump start it, but do have an electrical socket nearby like at home.  And a portable jump starter lets you charge p the battery without another vehicle, and by the roadside without the need for an electrical socket, so you are never stuck.

Alternator Problems in a Mercedes CLS-Class

car wont start alternator

The Alternator keeps the battery juiced up by harnessing engine power while driving. A worn out alternator can easily prevent your Mercedes CLS-Class from starting since it cannot recharge the battery, draining it completely so that one day you hop in your beloved Mercedes CLS-Class and it simply can’t start. Clues of a problematic alternator can be an illuminated battery or alternator warning symbol on your dash, faint headlights while idling, or a whirring noise from the engine while running.

Starter Motor Failures in a Mercedes CLS-Class

car wont start wont turn over

The starter motor is key to turning over the engine when you try and start up your Mercedes. If the starter is faulty, the engine can’t crank, preventing your CLS-Class from starting. Listen for clicking sounds when you turn the key or grinding as you try to start it, possibly meaning starter issues.

Fuel System Issues in a Mercedes CLS-Class

car wont start fuel filter

We’re not talking about running out of gas like a silly goose. Instead, it’s issues with the fuel system itself that could leave your CLS-Class unable to start up. Your Mercedes CLS-Class uses fuel to mix with air and runs the engine. Issues in fuel delivery like a clogged fuel filter or damaged fuel pump relay may mean the engine lacking the fuel it requires for ignition. Fuel injectors can also get clogged over time, so try a fuel injector cleaner like Red Line to clean them out and improve starting.

Electrical System or Wiring Problems in a Mercedes CLS-Class

car wont start electrical issue
Image Credit: MechanicAnswer.com

Ok, well yes that image is a joke, but I want to emphasize modern vehicles rely on electronics, opening up the number of things that can go wrong. With older cars, common culprits include blown fuses, spark issues, damaged ignition switches, or broken sensors. Electrical issues and electronics like these can all prevent your car from starting. Pay attention to intermittent starting, warning lights, or failure to crank as signs of an underlying electrical problem. Pinpointing and fixing these often needs a qualified mechanic near you.

Solutions: Let’s Get Your Mercedes CLS-Class Starting Again!

If you think you might know what the issue may be, it’s time to figure out the cause of your car’s starting failure, and then the next step is to attempt to fix the problem. Here’s advice for the common issues we’ve discussed up to this point:

How to Identify and Fix Battery Issues in a Mercedes CLS-Class

car not starting but battery is fine

The first step if a battery issue is suspected for the no start is to inspect the battery terminals. Ensure they are corrosion-free, secure, and correctly connected. Should you find corrosion or gunk buildup on the terminals, a baking soda and water solution can help clean them.

Once you have checked the battery terminals, you can check to see if the battery is just out of charge, or worse, it’s old and weak, or dead and needs to be replaced. For this, you can charge the battery in a few different ways:

If the battery charges fully and performs as expected, the issue may be resolved. However, if the battery has aged or lacks capacity, replacing it will be necessary. Otherwise, even sufficiently charging it to start your CLS-Class may only provide temporary relief before it runs out of charge again in the near future. Using a multimeter or OB2 scanner to evaluate the battery’s condition can determine if it’s worth preserving or requires swapping out. Suitable replacement batteries for your specific Mercedes can be found on Amazon here by entering your vehicle details to filter for the right fit and choosing a highly-rated seller.

Robby Recommends:

Portable Car Battery Jump Starter Charger - NOCO Boost Plus GB40

At Home Battery Charger - YONHAN - Fully Automatic

Jumper Cables by Energizer for Car Battery - Heavy Duty

NOCO Boost Plus GB40 1000A UltraSafe Car Battery Jump Starter

YONHAN Battery Charger Fully-Automatic

Energizer Jumper Cables for Car Battery, Heavy Duty

If charging your CLS-Class’s battery fails to solve ongoing issues like frequent draining and recharging even after installing a new battery, an underlying problem likely causes the excessive drain. Professional diagnostic services would then be needed to inspect and identify the root cause. You can also consult a mechanic online through us or obtain an instant quote from a mobile mechanic.

How to Identify and Fix Alternator Problems in a Mercedes CLS-Class

Car wont start replace alternator needed

If you suspect the alternator is causing your car to have issues starting, you can test it yourself. If you can temporarily get the vehicle running (you may need a jump start), and while the engine is running, disconnect the positive terminal of the battery. It’s probably the alternator if the engine dies soon after disconnecting the positive lead. Keep in mind though this test can be dicey and damage sensitive electronics in your wheels, so it’s best to consult with an experienced mechanic in your town or online first since this test risks damaging the delicate electronic gizmos in your Mercedes CLS-Class.

If you figure out that the alternator is the problem, it’s a case of having it replaced. I recommend consulting an online or local mechanic as they will advise you on how difficult the repair is for your specific model, and you can work out if you want to try it yourself, or with the advice of an online mechanic

If you do want to try it yourself or take it to a local garage, you can often buy the replacement parts yourself cheaper than at the garage, but you need to know what to get for your model of Mercedes CLS-Class. You find all the information you need about your specific vehicle by searching online for something like “dmv Mercedes vin check owner“, which is a purchasable report, that will give the specs for your vehicle and which parts are compatible, and then you can go get the alternator parts you need. However, an easier option is, Amazon probably has the alternator you need online, at a cheaper price, and their site easily shows which ones will go in your specific car model. Check the Amazon alternator page here

How to Identify and Fix Starter Motor Problems in a Mercedes CLS-Class

starter motor issues in a ford

If you question if the starter motor is the source of your CLS-Class refusing to start, listen for a clicking noise when you turn the ignition key. If heard, but the engine does not turn over, the starter motor likely requires replaced. You can take it to a local garage and have them repair it, or repair it yourself with the help and advice from an online mechanic guiding you. 

If you need it, one of the cheapest and easiest places to get a new starter motor, for your exact vehicle model is on the Amazon here.

How to Identify and Solve Fuel System Problems in a Mercedes CLS-Class

clogged fuel filter car wont start

If you suspect a fuel system malfunction might be to blame for the no-start, listen closely for the fuel pump hum when you flip the key to “on” before trying to turn over the car. The pump should make a quiet humming for a few seconds. Should no such quiet hum be audible, the fuel pump could be defective. Problematic starting, stalling, or poor throttle response may also result from a problematic or clogged fuel filter. Both pump and filter issues normally require a skilled mechanic to diagnose and fix them properly, often using fuel pressure testing and precise diagnostic gear. Later in this article, I detail the best ways to get help from a local Mercedes mechanic near you. 

How to Fix Electrical or Wiring Issues in a Mercedes CLS-Class

fuses to check when car wont start

If you think it’s an wiring issue, first check the fuses for the ignition system, and swap out any that have blown. If your CLS-Class starts after this, it was an effective, cheap fix! However, if it still won’t start, even sometimes, the ignition switch itself could be faulty. Warning lights on the dashboard could additionally mean a damaged component. These can be complex issues needing a professional mechanic to identify and properly repair (see below advice on local mechanics).

How to Prevent Starting Issues in a Mercedes CLS-Class

As grandad would say: “An ounce of prevention is worth a pound of cure”. Here’s how to prevent future problems starting your CLS-Class:

Routine Maintenance of Your Mercedes CLS-Class

Regular maintenance on car to prevent starting issues

Routine maintenance is critical to avoiding issues, including oil changes, battery checks, cleaning terminals, replacing the fuel filter as needed, and having a mechanic check over the vehicle regularly. If confused about maintenance for your model, consult a mechanic locally or online for guidance.

Drive Your CLS-Class Frequently

drive regular to avoid car troubles

If your Mercedes CLS-Class happens to sit motionless in your garage or front yard for weeks without being driven, the battery can reduce as it is not being charged up by the engine running, through the alternator. Try your best to drive your Mercedes CLS-Class regularly to maintain a charged battery. If you remember you have not driven your car in a while, take it for a short spin around town to ensure there is still a charge left.

Note: Letting the battery fully drain is also bad for its longevity, so try to avoid that.

Take Notice Of Warning Signs

Check Engine Control Light on a Vehicle Dashboard

If you notice any weird things like unusual noises, changes in driving and performance, or warning lights lit up on the dashboard, do not ignore them. These are often early signs of an issue that should be addressed ASAP before they escalate into larger problems later on. Consult with a mechanic locally or online about these problems and get advice on if they require attention.

When to Ask a Mercedes Mechanic Online

If you have limited time available, or despite putting in real effort on your own, you still can’t get your car to start, consider consulting a Mercedes mechanic online. It delivers expert guidance in just minutes from the comfort of home, and is far less expensive than a tow and diagnosis at the local garage.

Benefits of an Online Mercedes Mechanic

Happy mechanic repairing car looking at camera

Online Mercedes mechanics can review your symptoms, past repair history, and circumstances to provide troubleshooting steps tailored to your situation. With so many Mercedes mechanics available they can help fix nearly any problem, it doesn’t if matter it’s your CLS-Class that’s having issues or a Mercedes CLK-Class won’t start, the online mechanics can help sort anything in no time. And with many household budgets tighter these days, the convenience and affordability of online mechanics help, keep your wallet happy too.

You can explain the issues you’re having, ask Mercedes mechanics unlimited questions, and even upload photos and videos so you can demonstrate to the expert what you mean. You can connect with them via instant messenger or phone call, whatever you like. The Mercedes mechanic will ID the issue, recommend the top solution for your specific case, and even walk you through basic repairs step-by-step.

Whether you want an expert second opinion or are simply short on time, online repairs assistance is there when you need it. Give it a try to see firsthand how convenient fixing problems can be.

So feel free to try out our chat with a Mercedes mechanic service and see for yourself!

When and How to Get a Local Mercedes Mechanics Help

automobile mobile mechanic

When your Mercedes CLS-Class won’t start, and you are unable to repair it yourself, thinking about how to get your vehicle to the garage can be a nightmare. There are options like roadside services, that come to you and can provide simple fixes to get your car moving enough again, so you can get it to a mechanic garage for proper repairs. You can also use a towing service, but these can be costly, easily into the hundreds of dollars. A much better option is the use of a mobile mechanic, who will come to you at your home, place of work, or by the roadside, and carry out repairs there and then for you, so you can get your CLS-Class started again ASAP.

So if you think a mobile mechanic is the best solution for you, instead of searching on Google something like  “mobile auto repair“, the best in the USA that also covers most towns is YourMechanicI have personally recommended them to countless people across the country and they always have a great experience.

Reasons I recommend them:

  • They use experienced ASE-certified mechanics
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If you would like to know more, the process to use them is this.

  1. Visit their official website here: YourMechanic
  2. Get an instant free quote for what you need
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Conclusion

In short, when your Mercedes CLS-Class doesn’t turn over, it can be a total bummer. However, grasping what might be causing the problems, being able to diagnose them, and knowing what actions are needed in each case, and where to get help if needed, will be a huge help. Keep in mind that regular maintenance is key to avoiding most vehicle problems.

Frequently Asked Questions (FAQs) When a Mercedes CLS-Class Won’t Start

Mercedes CLS-Class won’t start but lights turn on?

If your Mercedes CLS-Class‘s lights turn on but it still won’t start, the issue may not be related to the battery. More than likely there is a problem with the engine starter. Investigate if you hear any clicking noises when attempting to crank the key. If so, the starter motor is trying to engage but failing. Have a mechanic check over the starter motor – it may need to be fixed or swapped out.

Mercedes CLS-Class won’t start but has power?

When your Mercedes CLS-Class has power (lights, radio etc work) but does not start up, there may be a fuel delivery problem. Issues like a faulty fuel pump relay could prevent fuel getting to the engine. Without enough fuel, combustion can’t happen and the engine won’t start. Check around the back seat when cranking the key – you should hear the fuel pump prime for a few seconds. If not, get a mechanic check the fuel system.

Mercedes CLS-Class won’t start but battery is fine?

If your Mercedes CLS-Class‘s battery tests fine and is fully charged, but the car still refuses to start, the underlying cause is likely electrical. Possible issues include a bad ignition switch, broken sensor, or wiring problems. As electrical issues can be tricky, diagnosis by a professional mechanic is best. They can correctly pinpoint the specific electrical fault and have it repaired.

Mercedes CLS-Class won’t start just clicking?

When you turn the key and just hear clicking but the engine doesn’t crank, the most common cause is a faulty starter motor. The click comes from the starter solenoid trying to engage the starter motor, but the motor itself fails to spin up the engine. As the starter motor needs physical fixing or swapping out, consult with a reliable mechanic to get your Mercedes CLS-Class running again.

What if my Mercedes CLS-Class won’t start up?

First things first, take a deep breath and try to stay calm. Check for any odd noises, flashing lights, or changes in how it runs that could point to the issue. Most likely the culprit is one of the common problems we will talk about here. If you still can’t pinpoint the exact issue, you’ll have to consult a trusted Mercedes mechanic locally or online.

Determine if my Mercedes CLS-Class won’t start because of a bad battery?

Clues that your Mercedes’s battery is the issue include, a slow cranking engine, dim front lights, and battery alerts lighting up on the dash. Also make sure the battery terminals are clean, corrosion-free, and tightly fastened. If your battery is worn out it’s probably best to just replace it fully.

How to prevent my Mercedes CLS-Class from failing to start in the future?

To prevent this nuisance from happening again, routine maintenance is crucial. This includes oil changes, checking the battery and cleaning its terminals, replacing the fuel filter when needed, and getting your Mercedes CLS-Class evaluated by a mechanic frequently. Additionally, make sure to drive the car frequently so the battery stays charged.

Can I consult an online mechanic if my Mercedes CLS-Class fails to start up?

Yes, you can. An online mechanic service like ours can offer immediate skilled Mercedes mechanic assistance and advice, without you having to leave your house. This is especially beneficial if your Mercedes CLS-Class is unable to start and is immobile in the parking area,.

How can services like MechanicAnswer.com lend a hand if my Mercedes CLS-Class won’t turn on?

We pair you with certified Mercedes mechanics who can offer proposals specific to your individual quandary. You can brief them about your auto troubles, ask unlimited questions as needed, upload images and videos so you can show in detail the issue. The mechanic will be capable to assist, diagnose the problem, and recommend the ideal plan of action and guide you through it.

Interesting Mercedes CLS-Class Facts

Did you know that the Mercedes CLS-Class was the first ever “four-door coupe” when it was introduced in 2004? That’s right, this sleek and stylish vehicle combined the elegance of a coupe with the practicality of a sedan, creating a whole new category of car. And get this – the CLS-Class is also available as a high-performance AMG model, with a powerful V8 engine that can go from 0 to 60 mph in just 3.5 seconds! It’s like having a sports car and a luxury sedan all in one. Plus, with its innovative technology and luxurious interior, the CLS-Class is truly a one-of-a-kind ride. No wonder you’re itching to get it started and hit the road!

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Which Mechanic Suits You?

  1. Chat with an Online Mechanic to get instant, unlimited help and advice for 1 full week, for just £5.
  2. Get help from a Mobile Mechanic. We  recommend Fixter. They will come to you and fix your vehicle at a time that suits you. Instant free quote online below. We recommend the online mechanic first, as it’s cheaper for you, and you may not need an in-person mechanic.

Which Mechanic Suits You?

  1. Chat with an Online Mechanic to get instant, unlimited help and advice for 1 full week, for just $5.
  2. Get in-person help from a Mobile Mechanic. We recommend YourMechanic. They will come to you and fix your vehicle at a time that suits you. Instant free quote online below. We recommend the online mechanic first, as it’s cheaper, and you may not need an in-person mechanic.

Choose Your Mechanic

1. Chat with A.I. Mechanic (Robot Robby)
  • Free 7-day trial
  • A.I. Mechanic that is trained by our human mechanic writers. As helpful as a human mechanic for expert advice, troubleshooting, and repair guidance.
2. Chat with a Human Mechanic Online
  • Join for just $5, and $39/month. Cancel anytime
  • Real human ASE-certified mechanics available 24/7

Which Mechanic Suits You?

  1. Chat with an Online Mechanic to get instant, unlimited help and advice for 1 full week, for just $5.
  2. Get in-person help from a Mobile Mechanic Near You. They will come to you and fix your vehicle at a time that suits you. If there are none near you, you will be redirected to the online mechanic.

Which Mechanic Suits You?

  1. Chat with an Online Mechanic to get instant, unlimited help and advice for 1 full week, for just £5.
  2. Get help from a Mobile Mechanic. We  recommend Fixter. They will come to you and fix your vehicle at a time that suits you. Instant free quote online below. We recommend the online mechanic first, as it’s cheaper for you, and you may not need an in-person mechanic.

Which Mechanic Suits You?

  1. Chat with an Online Mechanic to get instant, unlimited help and advice for 1 full week, for just $5.
  2. Get in-person help from a Mobile Mechanic. We recommend YourMechanic. They will come to you and fix your vehicle at a time that suits you. Instant free quote online below. We recommend the online mechanic first, as it’s cheaper, and you may not need an in-person mechanic.

Where Can I Find My VIN?

Your vehicle’s unique Vehicle Identification Number (VIN) can be found on the title document, the vehicle registration, and the insurance policy. It is a series letters and numbers like this as example: WAUGC0896JA235262. The VIN can also be located on the following locations on the vehicle itself:

how to find VIN on vehicle