Newer BMWs are now equipped with Auto Start-Stop function. The main purpose of auto Start/Stop is to save fuel.
Every time you stop at a red light or are stopped in traffic the engine turns off. Everything in the car including the ignition remains on. As soon as you take your foot off the brake the engine starts again automatically. It takes about 1 second for the BMW engine to restart.
BMW auto Start/Stop can be turned off. BMW will remember the state of Auto Start function even if you turn off the engine and park the car. In other words, when you enter the car again, your BMW knows if you had the Auto Start on.
How is Engine Auto Stop activated?
Several conditions need to be met for the engine to automatically stop and restart.
Here are the primary requirements.
- Transmission is in the Drive position.
- The brake pedal is pressed and remains pressed.
- Seat belt buckled
- Drive's door is closed.
If these conditions are not met you will notice a cross on the Start/Stop symbol on your instrument cluster.
Under certain conditions, BMW may not restart, for example, if the engine is turned off during auto shutoff, you open a door or remove a seat belt. If this happens to you, try restarting the car by pressing the Start/Stop button.
Why is my Auto Engine Start/Stop not working?
BMW auto-stop does not work on reverse gear.
BMW auto-start function does not work if you are driving at speeds less than 5 mph or about 8 km/hr. Your BMW instrument cluster may display a symbol stating READY which means the car is ready to start the engine automatically.
Your BMW auto engine start may not work in several situations. List of cases under which engine stop/start feature will not work.
- In extremely hot days
- In extremely cold days
- The interior temperature has not reached your desired level.
- The engine hasn't warmed up to optimal temperature
- Wheels are turned all the way to the left or right
- Driving in reverse
- The car battery is not fully charged
- At very high elevation
- Hood is not properly locked
- Stop and go traffic
- Used wrong fuel octane or too much ethanol
BMW engine starts even though I haven't started driving
In some cases, you may notice that the engine restarts, even though you haven't started to drive yet. There are several conditions that can trigger the BMW engine to restart automatically.
- The temperature inside your car has changed drastically from your desired temperature
- The car battery is being discharged too quickly
- If the BMW starts to roll with the engine off
- You move the gear shifter to Neutral, Reverse or Park.
- You move the steering wheel while the engine is off.
- The temperature inside the car increases too much.
- You press the A off button above the Start/Stop.
Problems with BMW Auto Start/Stop
If you experience problems with the Auto Start/Stop feature, you will need to read the fault codes from the control module. This can be done with a scanner that is capable of reading BMW specific fault codes. A generic OBD2 scanner cannot read fault codes or troubleshoot Start/Stop function.
For more information follow our article on How to read BMW fault codes