Auto Stop-Start

[PHA]

Has anyone had their auto stop function stop working? Mine was fine a week or so go but now refuses to operate. I have tried using the switch next to the selector and it seems to turn the function off OK. However, whenever I pull up and put my foot firmly on the brake I just get the A symbol with the circle around it and a diagonal line in the MFP. This even occurred last night when the engine was fully warmed and the air-con wasn't needed.

[Diesel_vert]

There are numerous requirements which need to be met before the vehicle will engage the start/stop function. These should be listed in the owners manual.

One reason I can think of (off the top of my head) is that the battery charge is currently below the required level before the start/stop function will engage.

[Amalgam]

There are people who would consider that an improvement. Myself for one.

I hate jerky restarts, the fact that it can get confused at a set of lights or stop start traffic. Call me old fashioned but I am not comfortable what it may be doing to the engine in terms of startup friction and wear and the wear and tear to the battery.

[DV52]

Has anyone had their auto stop function stop working? Mine was fine a week or so go but now refuses to operate. I have tried using the switch next to the selector and it seems to turn the function off OK. However, whenever I pull up and put my foot firmly on the brake I just get the A symbol with the circle around it and a diagonal line in the MFP. This even occurred last night when the engine was fully warmed and the air-con wasn't needed.

PHA: I'm one of the folk that thinks that stop/start is an accident waiting to happen! I'm so scared of it that I've switched stop/start off permanently on my Golf mk7 using a VCDS tweak that I have included elswhere on VWW.

For your purpose though, and assuming that the passat has a "discover media screen", there is a simple process for finding-out why stop/start is not working. I've included a list of instructions on how to do this (including all the required screen shots) on the following link. Hope that it helps

http://www.vwwatercooled.com.au/foru...ml#post1041607

[Eaglehawk]

Those instructions won't work in our Passats. I'm assuming they've got a RNS510, which won't be the same as the Discover in the Golf Mk7.

[Diesel_vert]

At this stage, I think customer satisfaction with a vehicle's start/stop function is proportional to how seamlessly the vehicle manufacturer has implemented it.

By the looks of things, there is much room for improvement.

There are people who would consider that an improvement. Myself for one.

I hate jerky restarts, the fact that it can get confused at a set of lights or stop start traffic. Call me old fashioned but I am not comfortable what it may be doing to the engine in terms of startup friction and wear and the wear and tear to the battery.

The battery fitted to passenger vehicles with a start/stop function should be of an EFB (enhanced flooded battery) or AGM (absorbed glass mat) type, which are designed to cope with lower charge states compared to standard batteries.

Likewise, the design and duty cycle of the starter motor should also be different from that of a standard part.

Engine start-up wear at full operating temperature should be low enough, if not negligible, as not to affect its expected service life.

[PHA]

Thanks all

The car is only 12 months old, it covered over 1000km only just over a week ago (and the Stop/Start was working fine then) so the battery should be charged, it is an AGM battery, and for us the function has worked seamlessly and without drama. I actually don't mind it.

Given all the above I don't understand why it's not working now. Maybe it's time to ask the local dealer?

[Mountainman]

Thanks all

The car is only 12 months old, it covered over 1000km only just over a week ago (and the Stop/Start was working fine then)

Only 1000km in 12 months - wow. That's often my weekly total.

[PHA]

No, I meant it covered 1000 km last week. It's done 20,000 so far.

[maca]

I had the same issue with mine a few months ago and as someone has previously mentioned; there's a full list of requirements necessary for the function to activate.

When I (eventually) get my car back, I want to have a look in the VCDS and see if there's a way to permanently disable it. I remember seeing a check box in one of the bytes but I'm yet to experiment.