Undoubtedly, BMW is a reputable brand. However, every car has its day when the mileage clocks in and wear and tear start affecting specific components of your vehicle. So, what happens when your BMW won't start, and there are no clicking noises?
Almost every vehicle owner has experienced this problem. The trick is to get down to the root of the cause and then find the most suitable solution for your car's problem. This article will explore why your BMW won't start and the reason why there is no clicking.
BMW Won't Start Symptoms
When the key is turning in your BMW's ignition, and there is no clicking sound, there is definitely cause for concern. Not only is your car not going to be able to drive you anywhere, but now you are faced with solving a problem with a budget you may not have.
Sometimes your BMW will not start when there is cold weather. The lights and the radio may come on, but the engine will not start. In some cases, you may find that not even a jump start will get your car started up again.
Below are some of the most common signs you may experience when your BMW won't start:
- BMW lights are flashing, but still no start.
- Pushing the start button or turning the key won't start the engine.
- Car won't start and shows the key symbol on your dashboard.
- BMW won't start, and no lights come on.
- Car won't start, even after replacing the battery.
- BMW won't start during cold weather.
- Car won't start, and there is no clicking when turning the key.
- Despite lights and radio coming on, the engine won't start.
- EML light is on, but the engine won't start.
What to Check First
You climb into the driver's seat, turn the ignition or press the start button, and your BMW won't start. So now what? First, you should inspect the basics:
- Is the battery OK? Your battery may be discharged or completely dead.
- Are your battery cables corroded or loose?
- Your BMW may not start when the automatic transmission is in “Park,” but does it start when it is in “Neutral”? If this is the case, you may have a problem with the neutral safety switch.
- Do you have fuel? It may sound silly or like an obvious problem, but sometimes you may forget to check your fuel gauge. It is also possible that your fuel tank is empty, but your fuel gauge is faulty and is still showing there is fuel.
- Does your car have an anti-theft system that is preventing you from starting it?
If you have identified that your car has fuel, it is not starting regardless of the gear you are in, and your anti-theft system is not locking you out, then you need to explore why your vehicle won't start in further detail.
Let's get to it.
Why Your BMW Won't Start
No-start problems with a BMW can range from hearing a clicking noise when you start it (or several clicking sounds) to having no power at all and not hearing another. You may also see that dreaded yellow exclamation mark on your dashboard.
The most common causes of why your BMW won't start include the following:
- Bad fuel pump or relay
- Weak fuel pump
- Worn spark plugs
- Defective starter
- Damaged key
- Bad ignition coil
- Electrical problems
- Weak key fob battery
- Engine temperature sensor / PCM coolant sensor
- Clogged fuel filter
- Empty gas tank
There are generally six possible causes for why your BMW won't start, and there are no clicking noises:
- A failed starter motor
- A bad connection between the battery and starter motor.
- A blown fuse in line between the battery and the starter.
- A discharged or failed battery.
- A failed system component, for example, the relay or safety switch.
- Corroded electrical connection may prevent electrical current from reaching the starter motor, such as corroded battery terminals.
If there is no clicking from the starter, then you may have a problem in the starting circuit. The starting circuit is responsible for driving the solenoid.
Let's explore some of these problems that have no clicking noises in a little more detail.
A Failed Starter Motor
If nothing happens when you turn the key in the ignition or press the start button, then it means your starter motor may have failed and is not turning over the engine.
A starter motor rotates an internal-combustion engine. It helps initiate the engine's operation under its own power by controlling your vehicle's electrical output when you turn it on. As the engine runs, your starter motor functions to protect your car's system and operates as a fail-safe.
A starter motor is made up of the following components:
- The yoke or main housing
- Overrunning clutch
- Field coils
A common cause of a BMW starter motor failing is a dead battery. In this case, you could replace the battery with a new one. If your battery tests OK and your starter motor still won't crank, there could be several possible causes behind this problem.
Below are some of the possible reasons:
- The starter solenoid control wire may have a bad connection.
- The starter solenoid or the starter motor itself may have failed.
- The ignition switch may have failed. The ignition switch is installed behind the ignition lock mechanism and is an electrical switch.
- There may be a problem with the neutral safety switch.
- There could be a problem with the BMW's security system that prevents the starter from functioning.
- Other electronic modules may be preventing the starter from operating, such as ECM or BCM.
Unfortunately, BMW's starting-system problems are difficult to diagnose at the best of times. It is important to pay special attention to the symptoms to help you find the cause and then the right solution.
A Discharged or Failed Battery
A discharged or failed battery could be the reason why your BMW won't start, and there are no clicking noises.
If your BMW has not experienced any previous starting issues, then the reason your BMW won't start is likely due to a dead battery. This is one of the most common causes behind your car not starting.
Below are some of the possible causes for a BMW to incur high battery discharge or battery failure:
- One of the electronics in your BMW is draining too much power or doesn't enter sleep mode. For instance, a telematics control unit (TCU) is known to drain a battery when it's faulty.
- Final Stage Resistor (FSR) causes battery draining in the BMW E39, E46, and E53. It is connected to the BMW's HVAC system (heating, ventilation, and air conditioning).
- iDrive navigation module. Two iDrive navigation modules are popular for causing a discharged or failed battery; the CCC iDrive and the M-ASK iDrive.
- Faulty alternator; A defective alternator will not be able to charge your battery. If your alternator diode becomes corroded, it can affect your battery charge and may even draw power. Test your alternator before purchasing a new OEM battery.
- Old battery; Replacing your old battery should be the last action on your list. If none of the above check out as the cause, then you can replace your BMW battery, especially if it is old and has served its time.
One way to test if your battery is the cause behind the problem is to jump-start your battery. If jump-starting your BMW works, then you most likely have a dying battery or a troublesome alternator. If this is the case, then you may need to replace the alternator or the battery and clean the connections.
A Bad Connection Between the Battery and Starter Motor
A BMW starter motor needs an extremely high electric current to turn over the engine. That is why it is connected to the battery with thick cables.
A negative cable is referred to as the ground cable. This cable connects the cylinder block to the negative “-” battery terminal. The positive cable connects the starter solenoid to the positive “+” battery terminal.
A poor connection at one of the battery cables can result in the BMW starter motor failing.
A Blown Fuse
Sometimes your BMW won't start because of a bad relay or a blown fuse. Luckily checking the fuses on a BMW is relatively easy. You can:
- Remove the fuse and visually inspect the fuse yourself.
- Use a digital multimeter to inspect the fuses.
Not sure where to find your fuse box? BMW fuse boxes can be found in one or more of the following locations:
- Trunk area
- Under the dashboard or to the side of it.
- Engine Bay
We have compiled a list of fuses you should remove and check when your BMW won't start:
- Engine management
- Starter Fuse / Relay
- Central locking system
- Fuel Pump Fuse/ Relay
- Immobilizer / Security Fuse
- Alarm system
- Ignition switch control module
- Engine control module (ECM)
- Main Relay
- DME / DDE / Engine Electronics Fuse
If the solution to your problem is not as simple as replacing the battery or a blown fuse, then it is advisable to allow a professional to inspect your no-start problem. Spending the extra dollars by using a professional could increase the lifespan of your car.
It is also important to service and maintain your BMW regularly to prevent and treat issues before they become a serious problem.