When a Mercedes Benz ML350 won't start the 3 most common reasons are a dead battery, an alternator problem and failed starter. But there are also a number of other issues that can go wrong causing your Mercedes-Benz ML350 either not to start or to have a hard time starting. This article will guide you through some basic info of how a starting system works, and the car components that may be blamed in case of failure. Also hopefully guide you on what action you can take to try to fix each issue.
ML350 Won’t Start: Different Scenarios and Possible Fix
Scenario# 1: ML350 Won’t Start and No lights on the dashboard
The battery may be totally dead or there may be no interaction between the battery and the vehicle's electrical system if no lights on the dashboard come on and no other electrical consuming components operate. Examine the battery terminals for tightness. A jump start might be appropriate if the battery is absolutely dead.
Scenario# 2: ML350 Won’t Start But Light Comes On
If your car won't start but the lights are on and the radio is playing, it may be one of a few different issues. The possibility of a dead battery is one of these problems. The dashboard lights and warning lights, headlights, radio and other electrical components can still get power while the engine cannot because something might be interrupting the amount and direction of power each unit needs preventing the car from starting. If this happens also check the fuses, fusible links, and the ignition Switch
Scenario #3: ML350 won’t start since the key won’t turn in the ignition
There are a few possibilities for why the key won't turn in the ignition: When the steering is locked by the ignition lock with the front wheels turned away or one of the front wheels is pressed against something, this occurs often. In this case, gently jiggling the ignition key while turning the steering wheel left and right can help to unlock the steering lock.
Scenario #4: ML350 won’t start and there is no sound nor crank when turning the key in the ignition
When you switch the ignition key to the “Start” position and nothing happens, it means the starter motor isn't turning the engine over. A low/dead battery or a lack of connection between the battery and the starter are the most common triggers causing a scenario when a Mercedes ML350 won’t start and there’s no sound nor crank when turning the key in the ignition.
If this happens look into the car’s battery and check the terminal cable connections for corrosions. If it is indeed corroded then you have to clean the cable connectors and the battery posts or replace the bad cables before trying to start the engine.
Also check the car’s starter. The starter’s solenoid which is attached at its top can go bad, as well as the inside components. You will have to replace the starter contacts, starter solenoid, starter assembly or repair the starter circuit as required.
Scenario # 5 ML350 won’t start and only makes a clicking noise
If you turn the key to “Start” position but the engine doesn't start, you'll hear a single or repeated click from the engine compartment. This is often triggered by a low battery or a faulty link between the battery and the starter.
Again check the battery and the terminal cable connections. If the battery posts and cable connections tend to be heavily corroded, clean them or patch them before attempting to start the engine. Check the starter as well since the solenoid at the top of the starter, as well as the internal components, could have failed. Replace the starter solenoid, contacts, and assembly, or fix the starter circuit as required.
Scenario # 6 ML350 won’t start but the engine cranks
There are a variety of possibilities when a Mercedes ML350 won’t start but the engine cranks, but we know it isn't a battery or starter problem. Keep in mind that a vehicle will still need air, fuel, and ignition to function. So make sure you have enough gasoline because it's possible that you might be just out of gas, or that the gas isn't getting to your car. The engine will not start if the wrong amount of fuel is injected into the combustion chamber, or if it is injected at the wrong time.
This would be another scenario where the engine will turn over but not actually run. A number of components, including the fuel pump and filter, fuel injectors, and fuel lines, may be to blame. Some of the alternative reasons are a stretch, but they do have an effect on the system. Begin by checking the fuel injectors for clogs.
The electrical spark isn't getting through to the spark plugs if it isn't a fuel issue. Examine the spark. The engine will not operate if there is no spark to ignite the fuel mixture in the combustion chamber. It can “crank over” or switch over, but it will never drive.
The problem with sparks isn't limited to the connectors. Examine the spark plug cables, the distributor or module, and the distance between the plugs. Both of these factors have a significant impact on the ignition system's operation.
Electrical problems with the ECM / PCM computer, or issues with the camshaft location sensor, shifter selector module, or driver authorization or immobilizer system can also prevent starting.
ML350 Won’t Start: Initial Fix
Before calling roadside assistance and taking your car to a mechanic here are some quick fixes that might work:
- Check under the hood. See if the battery and the battery cables are in working order. Loose cables/a weak or even dead battery could be the issue why your ML350 won’t start. Check to see if the battery is fully charged.
- Try Adjusting the Transmission. Let's imagine your car's automatic transmission is set to “park,” but it won't start. Start the car in “neutral” if that's the case. If it starts in “neutral,” a technical issue, such as a defective neutral safety switch, might be preventing the car from starting in “park.”
- Check your gas tank. While it might be a silly question to ask do you have gas? It does happen. Sometimes people forget to gas up or fuel indicators might be acting up. If your fuel is empty it’s definitely a reason for your car not being able to run.
- Check Engine Error codes. IIf your Mercedes-Benz starts and fails, another way is to recover the fault codes. To retrieve fault codes, you'll just need an iCarsoft MB II or a Launch Creader VII+.
These two scanners can read fault codes from the ECU, as well as the TCU, SRS, ESP, ETS, BAS, and a number of other control units. Use an OBD II scanner to retrieve the error codes of your Mercedes Benz.
- Tap the starter. Using a heavy object, gently tap the starter a few times, being careful not to pound it. Since you'll be tapping the electrical components back into contact with each other, this gentle tapping might be able to help power it back up in some situations.
Jumpstarting your vehicle can serve as a quick fix so you can get back on the road, but only temporarily. At least you could buy some time and take the vehicle to a qualified technician to get it checked out. But if a jumpstart still could not get your car to start, you’ll have no choice but to get the car towed and have that starter, which for sure has gone bad, repaired or replaced.
ML350 Won’t Start: Other Frequently Asked Questions
What causes a car not to start if the battery is good?
If your battery appears to be in good condition but your ML350 won't start after a few attempts of starting it then you might have a problem with the ignition switch.
What are the signs of a bad ignition switch?
The most common signs you have ignition switch trouble are the following:
- Car failing to start when turning the key
If the ignition switch fails while the engine is running, the ignition and fuel systems will lose control, causing the engine to stall. The vehicle may or may not be able to be restarted a short time later, depending on the exact problem.
If the ignition switch fails in the “on” position, which powers on the fuel and ignition systems, the vehicle will start but then stall. When the ignition switch is in the cranking position, power is temporarily provided to the fuel pump and ignition system, which may cause the vehicle to start. If it fails in the “on” position, however, it will cut power to the fuel and ignition systems as soon as the key is removed from the cranking position and placed in the “on” position.
- Difficulties powering on the accessories
Trouble turning on the vehicle's accessories is another sign of a defective ignition switch. The ignition switch can turn on the vehicle's accessories, such as the interior lights and center console, when the key is inserted and switched to the “acc” spot. If the accessories do not turn on when the key is inserted and turned, it may be a sign of a problem with the ignition switch or lock cylinder. Fuse and wiring problems may also cause similar symptoms, so getting the vehicle properly diagnosed is strongly recommended.
Other symptoms of Bad Ignition Switch are dashboard lights flickering, key not being able to turn and absence of noise from the starter motor.
Ignition switches, being a widely used switch in a car, like all electrical switches, gradually wear out and need to be replaced. If you think your vehicle's ignition switch is malfunctioning, have it tested by a competent technician to see if the switch needs to be replaced.
What fuse will cause a car not to start?
The cause of a car not starting may be a blown fuse in the starter circuit. Broken or corroded wiring, damaged or dirty battery or starter solenoid wires or even loose wires may prevent sufficient power from reaching the starter.
What are common bad starter symptoms?
Before we go into the common signs of a bad starter let us first get to know what a starter is. The battery drives the starter, which is a small motor. It starts the engine in your vehicle. A starter relay transmits power between the battery and the starter motor. You won't be able to back out of a parking spot without a jumpstart or tow if your starter relay and motor aren't working properly.
Common Signs You Have a Bad Starter
- Strange sounds or a clicking noise when turning the key or pushing the start button. You may also notice whirring or grinding noise when it’s about to die. But a starter can also go bad without any sound.
- The dashboard lights up but the engine doesn’t start.
- Engine won’t rev up even after a jumpstart. So you have no choice but to call roadside assistance.
- Smoke coming from your vehicle. The starter is part of your car’s electrical system so it is subject to short circuits and blown fuses. When you’ve been trying to jumpstart your car in vain the starter can overheat and cause more severe electrical issues. So as soon as you smell smoke, stop jumpstarting your car for you may already have blown the starter and other electrical components of your car.
- Locate the starter which is usually found on the driver’s side of the motor below the cylinder’s left bank. Check if it’s drenched in oil. In this case your starter has probably gone bad because of an oil leak. So watch out for oil leaks to avoid the more expensive issue of ruining your starter.
What causes starter problems?
Besides oil leaks there are a variety of other problems that could lead to a bad starter and that includes loose or dirty wiring connected on your starter, corroded batteries.
When your Mercedes Benz ML350 won’t start it can be a very frustrating and worrisome experience but hopefully with the help of this article you are able to get an idea of what could be going on and what you should do. Just remember to take extra caution and not get yourself in the process of doing an initial troubleshooting. If you are not very confident again feel free to ask for professional help.