Ignition on (engine off) on 48v mild hybrid system

parky1215 · 06-07-2023, 03:03 PM

On older BMWs without mild hybrid system, I could just hit engine start button without depressing the brake pedal, and this would put the car in ignition on (engine off) mode where I can connect OBD2 scan tool to scan the car.

However, such mode does not seem to exist on LCI with the mild hybrid system (eg. pressing engine start button without brake does not seem to do anything).

How do I put the car in the mode where I can connect OBD2 scan tool to scan the car without starting the engine? Or does the LCI car automatically put the car in ignition on mode as soon as I unlock and open the door?

GerryC · 06-07-2023, 05:21 PM

Quote:

Originally Posted by parky1215

On older BMWs without mild hybrid system, I could just hit engine start button without depressing the brake pedal, and this would put the car in ignition on (engine off) mode where I can connect OBD2 scan tool to scan the car.

However, such mode does not seem to exist on LCI with the mild hybrid system (eg. pressing engine start button without brake does not seem to do anything).

How do I put the car in the mode where I can connect OBD2 scan tool to scan the car without starting the engine? Or does the LCI car automatically put the car in ignition on mode as soon as I unlock and open the door?

Hit the Start button 3 times quickly without stepping on the brake. The car should enter Diagnostic Mode (You'll get a notice at the bottom of the primary display.)

You really want to be in Diagnostic Mode when scanning as it forces all modules on. For power savings reasons, modules not needed won't be powered up until they are needed.

parky1215 · 06-07-2023, 06:03 PM

Quote:

Originally Posted by GerryC

Hit the Start button 3 times quickly without stepping on the brake. The car should enter Diagnostic Mode (You'll get a notice at the bottom of the primary display.)

You really want to be in Diagnostic Mode when scanning as it forces all modules on. For power savings reasons, modules not needed won't be powered up until they are needed.

Thank you for the tip!
Do I just press start button once again to exit the diagnostic mode?

nZtiZia · 06-07-2023, 06:20 PM

Quote:

Originally Posted by parky1215

Thank you for the tip!
Do I just press start button once again to exit the diagnostic mode?

the only way I know to get out of Diagnostic Mode is to start the engine (brake pedal + Start button)

06-07-2023, 03:03 PM	#1
parky1215 Lieutenant Colonel 573 Rep 1,986 Posts Drives: F90 M5C \| G06 X6 M60i Join Date: Nov 2010 Location: Rancho Cucamonga, CA iTrader: (13)	Ignition on (engine off) on 48v mild hybrid system On older BMWs without mild hybrid system, I could just hit engine start button without depressing the brake pedal, and this would put the car in ignition on (engine off) mode where I can connect OBD2 scan tool to scan the car. However, such mode does not seem to exist on LCI with the mild hybrid system (eg. pressing engine start button without brake does not seem to do anything). How do I put the car in the mode where I can connect OBD2 scan tool to scan the car without starting the engine? Or does the LCI car automatically put the car in ignition on mode as soon as I unlock and open the door?
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