2012 Golf GTI (Mark6) Manual query

[minke]

Hi,

My car has a gear selection suggestion (top right of the centre console display). It will either suggest I pick a shorter or taller gear based on throttle position and load. I've always assumed it suggests around economy. That's fine if it does or doesn't do that I just want to be clear what I'm referring to so that my next paragraph makes sense.

I've noticed that my car can (often but not always) get confused about the suggested gear. Let me give an example. and this is with hot engines too but I've seen it when cold as well

Heading down hill in 3rd with 1500rpm on board and no throttle (so compression braking) the car will often say '3' or that third gear, which I am in, is right. But every now and then it will suggest 2nd gear (2 with a down arrow beside it) This is with NO THROTTLE!

I've had other times with very light throttle with 1500-2000rpm on board heading down hill it has also suggested that I was in to tall a gear. Not always.

So my question is - what dictates this value/suggeest? I'm assuming engine load (based on throttle position) but is there an internal switch that measures the angle of the car (ie pointing down hill or up hill?)

How can I used VDCS to test/re-calibrate this feature? I wonder if it may have something to do with my on-going http://forums.ross-tech.com/showthr...onse-when-releasing-throttle-2-0T-CCZ-engine/

thanks

 

[NZDubNurd]

The Stability Control(?) appears to be able to tell it you are going up or down.

I know in my 2006 Touran, when it had the 09G auto, it could tell - it would hold gears, but also change down unusually early on hills that start steep, quick: One road on the school run is almost dead flat, and 100km/h zone. In the middle is a small dumpy hill really sudden up and down. Cruising along at 100 (ish), this hill would confuse the car, as with no change of throttle, it would quickly drop down to 5th, though we had then crested the hill, so it would quickly change back to 6th as it levelled out on the other side (just as everyone goes (WHOOOOA! from the floaty tummy feeling!). It can't have done it based on throttle or load in such a short time - the car never even slowed down noticeably. On hills that start more gently, it doesn't do it like that, hanging onto top for a while, even though you DO increase the throttle.

It was also remarkably good at holding gears, and dropping down on my drive home; living on the back of an extinct volcano, means up-and-down and round-and-round is all you get, and it was never trying to change up gears too early - it would hold them longer, or on a very short run of hill that is between 8 and 10%, it would change down to second, and pull over 5000 RPM, even with very light throttle, I could even decelerate, and it would hold second and would hold it until the downhill on the other side.

So I suspect your Golf it doing similar magic, and wanting you to change down, to maximise engine braking, and possibly increase economy, as at 1500 rpm, it may be assuming you'll brake soon because the engine braking is decreasing, and it'll drop to an engine speed where it will start using fuel again anyway.

It's all speculation and conjecture, but it sure appears they use a sensor, wihich would make sense to me, that it's the Stability Control Sensors.