If all power is lost in the car, it could indicate a bad battery connection, bad wiring, or loose main wire harness, etc.
If a warning light comes on - it may be going in to Safe Mode.
Safe mode is the set of parameters that the car will use if it believes there is a fault with the engine that could cause irrepairable or long term damage.
Generally it is an excess in expected boost pressure entering the engine. This excess boost from the turbo tends to happen for 4 reasons.
The boost pressure sensor (MAP sensor) is faulty. The wastegate is seized shut or slightly open. The wastegate actuator is faulty. The air line to the wastegate actuator is damaged or off.
Obviously, if the sensor is faulty, it will tell the ECU lies about the boost pressure. If the wastegate assembly fails in any way it will fail to open to bypass the turbo. The turbo will continue to spin up, increasing the boost pressure, causing the fault.
Initially I would suggest disconnecting the battery for 5 minutes (make sure you know your radio code before doing this), this will turn safe mode off and your car should run normally again. Drive home with a bit of care, you may find the car might never do it again. If it does go into safe mode again, you know you have a real problem and not just a glitch.
Best to contact your dealer and have it checked out.
Answers & Comments
If all power is lost in the car, it could indicate a bad battery connection, bad wiring, or loose main wire harness, etc.
If a warning light comes on - it may be going in to Safe Mode.
Safe mode is the set of parameters that the car will use if it believes there
is a fault with the engine that could cause irrepairable or long term damage.
Generally it is an excess in expected boost pressure entering the engine.
This excess boost from the turbo tends to happen for 4 reasons.
The boost pressure sensor (MAP sensor) is faulty.
The wastegate is seized shut or slightly open.
The wastegate actuator is faulty.
The air line to the wastegate actuator is damaged or off.
Obviously, if the sensor is faulty, it will tell the ECU lies about the boost pressure.
If the wastegate assembly fails in any way it will fail to open to bypass the turbo.
The turbo will continue to spin up, increasing the boost pressure, causing the fault.
Initially I would suggest disconnecting the battery for 5 minutes (make sure you know your
radio code before doing this), this will turn safe mode off and your car should run normally
again. Drive home with a bit of care, you may find the car might never do it again. If it does
go into safe mode again, you know you have a real problem and not just a glitch.
Best to contact your dealer and have it checked out.