Everything You Ever Wanted to Know About the Start Stop Feature on your F30 3 Series
tags:stop/start n55 stop start n20 stop start f30post f30 stop start f30 news f30 forum f30 bmw f30 automatic stop/start bmw stop start bmw news bmw f30 forum bmw f30 bimmerpost automatic stop start 3 series stop start 3 series problems 2013 3 series
One of the most interesting, possibly obtrusive and certainly confusing new "EfficientDynamics" features added to the 2012 F30 3 series is the automatic stop start system. Stop/start is standard equipment on all new F30 3 series and is designed to save fuel while the car would otherwise be idling. The stop start functions differently depending on the transmission choice.
Stop/Start will shut off the engine whenever the car is brought to a stop, so long as the transmission remains in D and the brake pedal is pressed to keep the car from moving. The engine is shut off after approximately one second and the tachometer needle will point to the "ready" position. As soon as the brake is released the engine starts and you continue on as normal. The driver can also select P while the engine is off and release the brake pedal, by then selecting D again the car will automatically start.
Stop/Start will shut of the engine whenever the car is brought to a stop, the car is in neutral and the clutch pedal is released. The engine is shut off after approximately one second and the tachometer needle will point to the "ready" position. The car is automatically restarted when the clutch pedal is depressed and you continue on as normal.
- The engine can be restarted by the driver in anticipation of driving off by: briefly applying additional pressure to the brake pedal or by releasing the break pedal slightly. Both will cause the engine to start.
- If "Automatic Hold" is activated the car will hold itself once the car has come to a stop and the engine has been switched off freeing the driver from needing to hold the brake pedal. Applying the brakes will cause the engine to start automatically.
- It is possible to prevent engine shut down once stopped in order to be able to drive off quickly. Within one second of stopping apply additional force to the brake pedal and then release the additional pressure and continue holding the brake pedal with "normal" force. Whatever that means.
Why isn't my Stop/Start working?
There are numerous vehicle parameters that are monitored as a part of the stop/start function to ensure the driving experience is not impacted. As many of the factors are not possible to monitor it may appear that the feature is not working. Reasons why the stop/start may not shut down the engine include:
- The car is coasting (manual transmission)
- Brake vacuum reading is too low (manual transmission)
- Insufficient brake pedal pressure is being applied to hold the vehicle stationary (automatic transmission)
- Stopping on a hill/downhill with a 12% or greater gradient
- If the steering angle is more then 6 degrees
- If the steering wheel is still be moved after approximately one second of coming to a stop
- The system has not yet be activated by going over a speed of 5mph for automatics, 3mph for manuals since the last engine switch off
- If the gas pedal is being pressed (engine must be at idle speed only)
- You're coming to a stop from reverse
- The driver gets out of the car
- If Hill Decent Control (HDC) is activated
- If the engine is not up to temperature
- If the carbon canister is being purged
- if the grade of the fuel is too low for the engine
- Transmission adaptation is active (automatic transmission)
- The hydraulic pressure accumulator is not yet up to pressure (automatic transmission)
- Stop-and-go traffic - system is only activated by driving over 5mph for automatics, 3mph for manuals
- Batter charge is low
- Outside temperature is colder then 37.4 F / 3 C
- Outside temperature above 95 F / 35 C and the air conditioning system is on
- Fogging of the windshield is detected by the IHKA system
- Climate control system is on but passenger compartment has not yet reached desired temperature
- ABS system was used when coming to a stop
Alternatively the car may automatically restart outside the standard restart procedure if:
- The driver is moving the steering wheel
- The driver presses the gas pedal
- The transmission was shifted from D to P and subsequently back to D
- The transmission is shifted to N or R
- The battery charge runs low
- Outside temperature rises above 95 F / 35 C and the air conditioning is on
- Fogging of the windshield is detected by the IKHA system
- Low evaporator temperature is detected
Disabling Automatic Stop/Start
The stop/start feature can be manually disable by pressing the button above the engine start button. BMW is now offering the ability for stop start to remember the last mode, meaning if stop/start is shut off and you completely shut down your car, it will remember the last mode and will not automatically re-enable stop/stop start. This can be coded by your dealer, read the service bulletin here -
The Bimmerfest Long Term Review Project 328i is mated with a 6 speed manual. The stop start function impressively does work with the manual transmission, however, I find it odd to sit at a light in neutral with the clutch out. When I was taught to drive manual I was told to always leave the car in gear in case you need to move suddenly. Therefore I tend to sit at lights with the clutch in, in first gear, so the stop start function never acts. When I do remember to use it I think it is the funniest thing to have it shut off the engine. I'll use the feature to entertain passenger and show off the technology of the F30. The rare cases where I'm at long lights it is nice but my daily commute doesn't have enough lights to make the gas savings worth much. It is disappointing that it doesn't work in stop-and-go traffic, that is where I would expect the majority of fuel savings would be seen by F30 3 series owners.
On an automatic where it can function without any change to ones driving habits I think it is a great way to save on gas. If someone with an automatic can comment on how it is that would be great.
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