A BMW is a fantastic car to drive. These beautiful machines are filled with the latest and greatest technology on offer. This is part of the appeal of a BMW, but sometimes these features can be daunting to understand and even be a little bit quirky. For instance, why does my BMW shut off when I open the door?
All new BMWs are equipped with an auto stop-start system. This system activates when specific parameters are met by the car’s sensors. If the system is active with the engine running and the driver opens the door, the system will shut the engine off as a safety feature.
Read on to discover how this system works, what is required to activate it, and the easy steps to switch it off.
Why Does A BMW Shut Off When The Door Is Opened?
A BMW will automatically switch off the engine when the driver-side door is opened when the auto start-stop function is active. BMW has included this feature in all its new manual and automatic transmissions models as a safety feature. This ensures a driver is behind the steering wheel when the car’s engine is running.
This engine shut-off feature will ensure that the engine is not left running if the driver has forgotten to switch off the barely audible engine. The other reasons for the auto start-stop function are to minimize the CO2 emissions from the vehicle and to save on fuel costs.
Many different parameters must come together for the system to work—understanding how the auto stop-start system functions is the first step in having it work properly for the driver.
How Does The Auto Start-Stop Function Work On A BMW
The auto start-stop function switches off the engine every time the car comes to a stop, e.g., during traffic jams, traffic lights, and crossings. The process will automatically switch the engine on when it senses it is safe to do so and you take your foot off of the brake pedal.
The auto start-stop function receives information from various sensors on the vehicle. It will not activate for the following reasons:
- The engine is not at its optimal running temperature
- The air-conditioner is running
- If the motor is conducting a cleaning cycle
Another function of the auto start-stop system that may be a surprise is that it will switch the engine on automatically if it senses that the battery has a too low voltage. Also, if the vehicle starts rolling forward or if any condensation develops on the windscreen.
The auto start-stop function on the BMW is designed to recognize the difference between a quick stop and an extended stop, so it won’t switch the engine off for a short stop.
How To Use The BMW Auto Start-Stop Function
The start-stop function is available in both the manual and automatic transmission BMWs. Each transmission type activates differently.
How To Use A Auto Start-Stop Function In An Automatic BMW
The BMW auto start-stop function will switch off the engine when the brake peddle is held down after the car has come to a complete standstill. When the system is active, a signal will illuminate in the instrument cluster. The system will start up the engine when the brake peddle is released or the steering wheel is turned.
How To Use A Auto Start-Stop Function In A Manual BMW
The BMW auto start-stop function will only activate when the following parameters are met and will not activate if the vehicle moves:
- The car has come to a stop
- The clutch has been depressed, and the gear lever moved into the neutral position
- The clutch pedal has been released
The engine will start up again when the clutch is depressed, and a gear is selected.
How Does The Auto Start-Stop Activate On A BMW
The auto start-stop system activates when the car’s sensors have met the following condition. If not all the conditions have been met, a start-stop symbol will illuminate on the dashboard:
- The gear lever must be in the “D” position (automatics)
- The gear lever has to be moved to neutral (manuals)
- Unfastened seatbelts
- Driver’s door has to be closed
How To Disable The Auto Start-Stop On A BMW
I have a vehicle equipped with an auto start-stop system. Personally, I think it’s a cute idea and it may even save me on gas mileage from time to time, but I find the constant engine shut-offs in traffic to be extremely annoying. Therefore, I turn my auto start-stop system off and I would recommend the same to anyone who finds the system to be a nuisance.
The auto start-stop function can be manually disabled if it becomes too annoying in traffic. This can be done by pushing the “A off” button on the dashboard. When it is disengaged, a LED light will illuminate to indicate that the system is deactivated.
Unfortunately, this will only deactivate the system until the car is manually switched off. It will be reactivated again as soon as the vehicle is switched on again.
To have the functions disabled on startup every time, the car will need to receive some coding from a BMW specialist. You can take the vehicle to a dealership or take it to an independent shop. BimmerTech is also a great resource for BMW coding modifications.
You can check out a good video on disabling the auto-stop below!
Why Does The BMW Auto Start-Stop Not Activate?
Suppose the auto start-stop system is not activating. In that case, it may be due to one of the following parameters not being met on the vehicle.
The Reasons Why A BMWs Engine Does Not Auto-Stop:
- The vehicle has not accelerated to 9mph (Automatic) or 5 mph (Manual) after the engine has started
- The car is moving forward
- The brake assist vacuum is not sufficient
- Not enough brake pressure being placed on the brake peddle
- Hydraulic pressure accumulator has low pressure
- Unfasten driver seatbelt
- The engine has not reached ideal operating temperature
- Low battery voltage
- Outside temperature is less than 37.4°F
- Outside temperature is higher than 86°F
- Climate control is on but has not reached the desired temperature
- If the BMW is parked on an incline or decline of more than 12% gradient
- The Hill Descent Control is running
- Steering wheel angle of 6° or higher
- Steering wheel setting adjusted after the vehicle has come to a standstill
- The accelerator pedal has been pressed
- Reversing
- The driver leaves the vehicle
- DPF is not functioning or blocked
- Poor fuel quality
- Fogging or moisture on the windscreen
- The ABS has been activated
The Reasons Why A BMWs Engine Does Not Auto-Start:
- The driver’s side door has been opened
- The drive side seatbelt has not been disengaged
- The transmission shift knob is in the “P” position
- The BMW engine is switched on by the auto start-stop system
- The battery is discharging irregularly
- The vehicle rolls while the engine is off
- The internal temperature has been adjusted
- The gear lever has been moved
- The steering wheel has been moved
- The “A off” button had been depressed
Conclusion
A BMW shuts off when the driver’s door is opened due to the auto start-stop system installed on the car. The system detects that there will be no driver behind the steering wheel when the engine is on, and as a safety feature, it shuts down the engine.
There are many reasons that the system will not shut down or start the BMW engine. This can be due to a low voltage battery, poor fuel quality, or a disengaged driver seatbelt. The auto start-stop system can be deactivated but will reactivate every time the car is started. My advice is that if you find the auto start-stop function to be a nuisance, have a professional update the coding to disable the function.
References
https://mbworld.org/forums/gle-class-v167/757721-vehicle-shut-off-when-driver-door-opens.html
https://www.youcanic.com/wiki/bmw-engine-auto-start-stop-feature-explained
https://ownersmanuals2.com/bmw-auto/x1-2021-owners-manual-78221/page-100