Start/Stop has stopped since MOT E91

[eatontrifles]

Since I had my MOT test done three weeks ago (passed with no advisories, thanks for asking) the auto stop/start hasn't worked on my LCI E91. It was working fine before. Part of me is glad, but like the lovable rogue that it can be, a part of me is missing it.

I know there's certain conditions that need to be met but it should all be fine, I've done four long (over 200 miles) trips since so the battery has easily had a chance to sort itself in case it dropped a bit during the test. No warning lights on the dash etc.

Any ideas? Would the MOT place have disabled it somehow?

[ManiacGT]

Unlikely MOT. Perhaps a drop in temperature recently? Tho perhaps not if you've run it 200 miles and it's still not working.

[andyiley]

eatontrifles said:

Any ideas? Would the MOT place have disabled it somehow?

Have you asked them?

I don't know if it is normal to do so, but there are parts of the test where they do want it to keep running at idle, so perhaps they might.

[graham22]

Could it be something simple like the air-con being turned on by the MoT centre to demist the car. Not sure if it applies to your car but I understand some cars won't 'stop' if the air-con is working.

[anonymous-user]

This might help?


http://www.bmwblog.com/2012/08/13/bmw-dealers-can-...

[4rephill]

andyiley said:

eatontrifles said:

Any ideas? Would the MOT place have disabled it somehow?

Have you asked them?

I don't know if it is normal to do so, but there are parts of the test where they do want it to keep running at idle, so perhaps they might.

You can turn the system off by pressing a single button so why would they permanently disable the system? - They simply wouldn't bother.

Surely the first thing to do would be to get it confirmed that the Stop/Start system is no longer working and then find out the reason for the system not working before pointing the finger at the MOT garage?

[andyiley]

I don't know how his system is enabled or disabled, nor was I pointing a finger at the garage, I said to ask them if they had done it.

Until the OP knows that how can he know if there is a fault or not?

[eatontrifles]

Thanks for all the responses. The garage is just an MOT place rather than a dealer or indie so I doubt they'd have anything sophisticated diagnostic-wise.

The outside temperature occurred to me as well but it's generally been over 10 degrees until this week and after a 6 1/2 hour drive to Cornwall a couple of weeks ago it was up around 15 so I don't think it's that.

How would I go about seeing if the system is functioning? I don't have a laptop diagnostic tool although it's something I've been thinking about getting if anyone knows of a lead/software combo that would work?

Nothing else has changed from 'normal', it before the MOT either by the way - it would still function with the air con turned on etc.

[andyiley]

The garage might just be an MOT place, but you still need to ask if they have done anything.

[4rephill]

eatontrifles said:

Thanks for all the responses. The garage is just an MOT place rather than a dealer or indie so I doubt they'd have anything sophisticated diagnostic-wise.

The outside temperature occurred to me as well but it's generally been over 10 degrees until this week and after a 6 1/2 hour drive to Cornwall a couple of weeks ago it was up around 15 so I don't think it's that.

How would I go about seeing if the system is functioning? I don't have a laptop diagnostic tool although it's something I've been thinking about getting if anyone knows of a lead/software combo that would work?

Nothing else has changed from 'normal', it before the MOT either by the way - it would still function with the air con turned on etc.

By all means ask the MOT garage if they've disabled the system, but I seriously doubt that they will say they have (and disabling the system permanently is far more complicated than simply pressing the button to switch the Stop/Start system off every time they would need to).

To get the system checked you're going to need to take the car to either BMW or an Indie specialist who has good knowledge as to how the system operates. There are a lot of parameters that can affect the systems operation and they all need to be checked.

[eatontrifles]

Spoke to the MOT place today and they confirmed that they wouldn't have disabled the system save for pressing the button on the dash. They've offered for me to pop in on Saturday morning and they'll plug in their diagnostics kit & see if anything is flagged up that might be causing it.

[eatontrifles]

The car was plugged in this morning and checked over at the MOT garage who confirmed that the system is showing as active and the usual parameters all look OK - clutch, gearbox & brake pedal sensors etc and no ECU errors other than brake pads from when I replaced them a few weeks before the MOT.

They suggested disconnecting the battery for ten minutes or so might reset the ECU and reboot the system in case it had got confused for some reason. Any more thoughts?

[eatontrifles]

Three and a half months on and yesterday, the stop/start reared its head again and appears to be working as normal. I can only presume that something during the MOT test spooked it and it has taken this long or that many engine starts to reset back to functionality.

Merry Christmas!

[c2mike]

Strangely just got my V8 M3 back from a brake fluid change and its first MOT (turned 3 years old). Was MoT'd at BMW dealer and the stop/start has stopped working since. Booked in for a diagnosis on Monday - I'll update when I learn more.

[Jon1967x]

If you've not tried, I'd manually disable and then enable it again a few times and give the car time to both warm up and fully charge the battery (I imagine on an MOT there's a lot of time sitting there with just the ignition on)

[eatontrifles]

Jon1967x said:

If you've not tried, I'd manually disable and then enable it again a few times and give the car time to both warm up and fully charge the battery (I imagine on an MOT there's a lot of time sitting there with just the ignition on)

I tried all that kind of stuff on mine, leaving it untouched or off for whole journeys, on and off numerous times and I went on many long journeys without any change. It just suddenly started working again.

[c2mike]

Dealer says battery was too low to allow stop-start. I think it was run down during the last service (which included some dashboard work to eliminate a rattle). Strange that several 20+ mile runs were not enough to naturally build the charge up sufficiently. Anyway, problem solved.