Very Interesting Finding...DSG Gearbox

[nomadx38]

Hey guys,

Thought I would just mention this interesting observation and as I don't see it as a problem I don't want to put it in the problems thread. (I'm happy for it to be moved if needs be)

But anyway recently I put some H&R lowering springs on my car (only on the back so far) and since doing so I have found that my DSG is much more responsive (and as a result more drivable) than before.

I'm sure your probably thinking in crazy but bare with me. What I'm thinking is that because of the slant the car is on now (5.5cm lower in the rear) it thinks the car is constantly going up a hill, as a result it:

Holds first gear much longer! And actually clamps down on the clutches hard for a very quick take off. Also seems smother than before with less delay from the brake. Another added bonus is that it re-engages 1st under 5km/h and sufficient throttle

Unless the road is perfectly flat (or down hill) it will stay in 6th - unless enough boost is been made.

Hill start assist modes still work as normal (so both forwards and reverse)

If you lift off the throttle it will hold a gear longer (about 1-3 seconds) instead of immediately shifting down to the next gear.

When off the throttle and you go bellow the tick over rpms (1050) it will engage the next gear (for example from 7th to 6th) much quicker meaning less delay and more boost.

When going up a hill (with very light throttle) it will start kicking back gears to keep it in the power band. The gearbox has always done this but its stepping back 1-2 more gears now

Generally feels like its more engaged and thus little throttle application will actually see the car progressively pull instead of it trying to move like a fat person (take no offence - you know what I mean ) - but this could just be the effect of all the above points

The thing I really want to know is, where is the sensor that detects the pitch of the car located - and maybe I can manipulate it. And/or I wonder if VCDS can change its parameters.

I only say this because the springs are ROCK HARD and I wouldn't mind going back to stock but i want the gearbox to keep working properly!

[cappuccino]

Hey guys,

Thought I would just mention this interesting observation and as I don't see it as a problem I don't want to put it in the problems thread. (I'm happy for it to be moved if needs be)

But anyway recently I put some H&R lowering springs on my car (only on the back so far) and since doing so I have found that my DSG is much more responsive (and as a result more drivable) than before.

I'm sure your probably thinking in crazy but bare with me. What I'm thinking is that because of the slant the car is on now (5.5cm lower in the rear) it thinks the car is constantly going up a hill, as a result it:

Holds first gear much longer! And actually clamps down on the clutches hard for a very quick take off. Also seems smother than before with less delay from the brake. Another added bonus is that it re-engages 1st under 5km/h and sufficient throttle

Unless the road is perfectly flat (or down hill) it will stay in 6th - unless enough boost is been made.

Hill start assist modes still work as normal (so both forwards and reverse)

If you lift off the throttle it will hold a gear longer (about 1-3 seconds) instead of immediately shifting down to the next gear.

When off the throttle and you go bellow the tick over rpms (1050) it will engage the next gear (for example from 7th to 6th) much quicker meaning less delay and more boost.

When going up a hill (with very light throttle) it will start kicking back gears to keep it in the power band. The gearbox has always done this but its stepping back 1-2 more gears now

Generally feels like its more engaged and thus little throttle application will actually see the car progressively pull instead of it trying to move like a fat person (take no offence - you know what I mean ) - but this could just be the effect of all the above points

The thing I really want to know is, where is the sensor that detects the pitch of the car located - and maybe I can manipulate it. And/or I wonder if VCDS can change its parameters.

I only say this because the springs are ROCK HARD and I wouldn't mind going back to stock but i want the gearbox to keep working properly!

This is a wild guess, but I would imagine this is because of the traction control.

By changing the springs you may have better traction, and as you have better traction the traction control will intervene less cutting off the power during acceleration.

Remember that the car does have undefeatable traction control like all euro cars these days. Even when you have it 'off' or the dash warning doesn't flash, the traction control is always intervening.

Basically, if you want to change back to more comfortable springs (i.e. less traction), but you want to keep the power, get the traction control turned off.

Please note, that you cannot do this via the traction control button or VDS.

I've heard you need to flash something... get a professional to do this!

But remember, there are other risks when you get rid of the traction control... so drive responsibly

[gavs]

Got nothing to do with traction control whatsoever and the physics of what you have implied is around the wrong way my friend. nomadx38 has fitted the rear springs which have lowered the rear of the vehicle and not the front, gravity then lends more weight transference rearward and lightens front axle weight, theoretically reducing front wheel traction. Plenty of us have also used VCDS and others have altered coding with no problems without any training (nomadx38 being one of the most experienced with the 6R polo) so recommending a "professional" do it is a bit moot Traction control can be turned off but ESC cannot but again, having nothing to do with traction control it doesn't really relate.

Yes there is some form of inclination monitor in the car which triggers hill hold/hill start assist on the car but I haven't the foggiest where it is or if it can be programmed using VCDS. It also helps control gearshift points so as to not big down the engine in too high a gear for a hill and yes, it will also hold gears longer. I don't know about the clamp pressure though because this is generally dictated by the engine rpm and I didn't think it could be monitored in VCDS.

RE spring stiffness, they will take a minimum of 5000kms to bed in and soften up to their intended spring rates. Your car when new was exactly the same but being on 15's to begin with you wouldn't have noticed it and it is quite a while ago

[nomadx38]

Ok so it's now been 1 week since l lowered the car and the gearbox is still going strong. I can actually say (in a very long time) that I'm enjoying the car!

I honestly don't want to lower the front just to keep it running good.

I also did a scan in VCDS for fault codes and I finally have one...yay?

"Brake light switch [F]" - Implausible signal.

Fault was lodged at 48000km and my springs were put in at 52000km so the springs didn't brake anything. Could possibly explain the erratic gearbox behaviour. Maybe because the car is on a slant, gravity (or something else) is influencing the switch making it work now.

Either way ill keep people posted...

[nomadx38]

UPDATE!!!

As my bro also has a Polo I borrowed a part to do some testing on. Changed over my brake switch and...SUCCESS!!!!!!

DSG worked flawlessly. No dropping of clutch, smooth operation, excelent throttle response! and the fault code "Brake switch [F] - Implausible Signal" is also gone, which is weird considering its not meant to erase codes itself but maybe I touched somthing.

As soon as I put the old switch back in started having weird shifts and dropping the clutch in 2nd. I would like to point out that it has not thrown up an error for the old switch...yet! This doesn't surprise me as I have had problems from 22000km without a fault code until 55700km so this is a clear example when diagnostics don't always work correctly.

Also comparing the parts my brothers switch is stamped 4.11 and mine is stamped 2.11 (so I assume my switch is 2 months older) yet both my bros car and mine were made on the exact same day, 400 numbers apart on the vin number in June 2011. So I have a really old switch In my car so chances I got a bad batch or???

I will go to buy a switch (hopefully it doesn't cost too much) and do testing for a week to 100% confirm but I think this test has brought many new things to the table regarding DSG issues an operation.

[gavs]

I'd putting in a claim to the dealership too and VGA for compensation because if that is the case, then the amount of time and heartache it has caused is ridiculous.

[nomadx38]

Ok so $45 and 10mins later the new switch is in! (and it looks compleatly different, not even the same manufacturer any more) - a new genuine part, superseding the old one.

Preliminary results from the drive around the corner are very good. Not a hickup and throttle response is excelent! Just a little push it will go from 7th @1500rpm to 4th @ 4000rpm in an instant and right on the power.

On that note it feels like its more powerful...how you ask? I think before it was cutting the throttle for like a millisecond and when you close the throttle you loose boost...which would explain it going like a dog and hesitating.

Haha and the takes offs - OMG just like a torque converter gearbox except that you are taking off quickly. I never imagined that it could take off so smooth but this is what I have been missing for 12 months.

More testing to the end of the week until I can confirm for 100%.

Should be peaches for the cruise this sat!

[gavs]

Ok so $45 and 10mins later the new switch is in! (and it looks compleatly different, not even the same manufacturer any more) - a new genuine part, superseding the old one.

Preliminary results from the drive around the corner are very good. Not a hickup and throttle response is excelent! Just a little push it will go from 7th @1500rpm to 4th @ 4000rpm in an instant and right on the power.

On that note it feels like its more powerful...how you ask? I think before it was cutting the throttle for like a millisecond and when you close the throttle you loose boost...which would explain it going like a dog and hesitating.

Haha and the takes offs - OMG just like a torque converter gearbox except that you are taking off quickly. I never imagined that it could take off so smooth but this is what I have been missing for 12 months.

More testing to the end of the week until I can confirm for 100%.

Should be peaches for the cruise this sat!

Good job mate! I'd be walking into the dealership though and taking the 'tech' for a drive and asking for a refund on the purchase price of the part.

[Hail22]

Good job mate! I'd be walking into the dealership though and taking the 'tech' for a drive and asking for a refund on the purchase price of the part.

Yeah let him do that Gavin...remember what VWAG do to people like that right? "So you changed the part yourself without having any technical training from VW engineering blah blah, Sir...your warranty is null in void".

VWAG and the brand is nothing short of bullies...watch the next quarter in sales...it looks to be down another 15-18% on top of the original 35% sales drop forecasts a few months back!

[Gigitt]

Your faulty brake switch might have been activating launch control :p

Or when faulty switching on your brake signal so that the DSG would release then apply the clutch suddenly with much more clamping force.