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2015 Cooper S Engine auto start/stop Problem

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33K views 16 replies 11 participants last post by  Taitam  
#1 ·
Hi all,

I just got my new 2015 Cooper S auto transmission. It has the engine automatic start/stop function, which means when you stop the car in front of a traffic light, as long as the transmission is in "D" and your foot is on the brake pedal, the engine will stop automatically to save fuel. And then if you release the brake pedal, the engine will start automatically.

Problem:

The problem I found with this function is that after the engine stops and while my foot is still on the brake pedal (without loosing any pressure on the pedal), the engine will automatically re-start after 15-25 seconds. I called the dealer and they said it won't re-start unless my foot release from the pedal. I drove my car to the dealer and have another loaner car, which is the save model. This one will auto re-start without releasing the brake pedal after exactly 50 seconds (I tested 3 times using my stop watch on the iPhone).

How does this function performs in your Mini? Please let me know.
 
#2 ·
I can only speak on behalf of the manual but if mines stops in town a few times over mins, it's prob draining the battery, so it either won't stop or will re-start before moving away as it needs the energy to maintain the electrics if say heaters is on or heated seats for example.

I'm not a fan and switch it off most of the time.

Also may not be dependent but I was always taught not to to sit there with the brakes on, possibly only relevant if the brakes are red hot but if you apply them on In one place while at temperature you have the potential to warp discs
 
#4 ·
I think there's a quite a bit of stuff going on here, electronic-wise. I've been in a position where I've just started the car in the morning, got to a junction and it's automatically stopped, but if the traffic means I'm there for some time (tens of seconds) the engine will eventually start up again despite being stationary.

If however, I'm in creeping traffic, the system knows not to continuously start and stop if you're only going a yard or so.

I am lead to believe that these are issues that are meant to happen. The first to ensure you don't wear down the battery and the latter because it would drive you insane if you were hardly moving.
 
#6 ·
Apparently there are a number of things that will cause the engine to restart uncommanded:

--Poor battery condition
--Battery voltage/available current too low (too many start/stops)
--Excessive cabin temp (hot OR cold)
--Steering wheel movement
--Turn signals
--Impure thoughts on the part of the driver
--Disgruntled spirits from the underworld
--It's Tuesday

I thinks that's most of them, but YMMV. Check the manual.
 
#7 ·
Depends what is on and how much drain the r is on the battery. If it kicks in the car monitors a variety of parameters eg esp air con or heated seats and then switches the engine back on. Read up on the manual and apparently the car will tell you if you have it on the right menu setting on the central screen.
T h ere are lots of reasons for it to put the engine back on all to do with protecting you the car and the battery. V clever.
 
#9 ·
i have an auto cooper s & the stop/start doesn't exhibit this behavior. Although I've never timed a stop it definitely holds for more than 15-20 seconds. in fact i don't think I've ever known it re-start without some input from me such as lifting off the brake, moving the gear lever etc. There are occasions where the stop/start doesn't kick in at all & this is usually because the engine or cabin isn't warm enough
 
#10 ·
What Hat said. But I have a cooper manual.

From what the OP describes, it sounds like the function may have a problem. I leave mine on all the time and am getting used to how it works, e.g., in very cold weather it may go off for a minute or two then start up again on its own without driver input. I get it. Now that I've studied how it works and have lived with it a while, when it goes off or on I understand why. With fuji's problem, it's not making sense unless there's something he's overlooking. Definitely worth a dealer check.
 
#11 ·
My gut tells me it's working properly.

Sometimes it'll auto start after seconds, others it will take a minute or two. I think it really depends on all the factors previously mentioned. For me, the A/C is ALWAYS on, as is the radio.

Just keep an eye on it.

JP
 
#13 ·
Thanks guys for all your reply. I just bought the car for around 10 days. I usually have the A/C on with 1/4 of max air, both sides 70 degree F. Also I'm keeping the music on (although there is some problem with the Bluetooth streaming, see my other thread). Almost all the time the engine will auto-restart without my foot releasing the brake pedal in less than 20 seconds.

I drove to the dealer and have them check the vehicle yesterday and they kept the car and give me a loaner car. I set the A/C to be max air flow and also have the music on to have a max battery drain. However, the loaner car I am driving doesn't have the same problem with my car, it can last at least 50 seconds, sometimes more than 2 mins. I am doubting that there is something wrong with my new mini's battery?