When I turn my car off, it continues to run. Engine doesn't shut off
It may sound strange but there may come a time that your car will refuse to turn off even when you remove the key. Taking out the key or pressing the Start/Stop button does not shut off the engine.
Car won't turn off when removing key
Key out of ignition car still runs
Car keeps running after ignition turned off
Engine will not stop when you press Engine Stop button
Problem - Car Won't Turn Off
In this situation, as we turn off the ignition the engine continues to run. Pressing the stop button does nothing. Inserting the key into the ignition unlocks the steering column and turns on the ignition but it does not shut off the engine when the key is removed. Car looks like it is turned off, with all the instrument cluster lights turned off.
The problems is that the engine is still running. The vehicle still responds to the gas pedal.
How to turn off a car that is still running
Do not try to disconnect the battery.
It is not recommended to start removing random fuses.
Your car may not restart.
Drive your car to a safe location. Keep in mind that your car may not start again after you get it to turn off. So drive it home or to a place that would be ok to leave the car parked.
Locate the fuse boxes on your car. If you are not sure look it up on your owners manual. Typically there is a fuse box in the engine bay and one on the side of the dashboard. Some models have a fuse box in the trunk as well.
Determine the fuse and relay for the fuel pump.
Remove the fuse for the fuel pump or the relay.
Your car engine dies within 10 seconds.
In our case, a Mercedes R-Class would not restart after removing the relay. To fix this problem we had to disconnect the battery and reconnect it in order to get the car to start again. So far the problem has not reoccured.
Fuel Pump Relay
The fuel pump relay may bind and get stuck in the ON position. It sends power to the fuel pump even when the engine is turned off. Replace the fuel pump reply. Even though the relay may still be appearing as it is working, it may be binding and keeping the fuel pump running.
Ignition Module / Keyless Start
The ignition module may fail or if your car is equipped with an Engine Push to Start button the Keyless module could be the culprit. Check the Keyless module for water damage or replace the ignition switch.
Start Stop Button
On vehicles equipped with Start/Stop convenience feature the engine may not stop when you press the STOP button. This problem can be caused by a defective Push Start button. If the button stops working, it may need to be replaced. Depending on the vehicle the button may be integrated in the ignition module and may need to be replaced with the module. It is possible to open the ignition module and repair the switch without replacing the module. You will have to find an independent repair shop for this procedure because it is very unlikely for your dealer to repair an old ignition module. If the module has to be replaced, it will require programing and coding which in most cases will cost over $1000 for parts and labour.