The other thing to be wary of is that declining the fix may mean you are declining any updates for the ECU and other vehicle systems - worth checking if it's applied separately or whether it'll be bundled into any software updates as a mandatory component of the update

Also had the"fix" letter today and will not be interested in getting it done as nobody knows how it will effect DPF/EGR,i think the car will be 3 years old in April and so far it is fine and if something fails when the warranty expires I don't think Skoda will be very helpful one way or the other.

Dare I say it, but if I was in the market looking for a used CR170 Yeti then I would pay more for one that hasn't had the fix applied than one that had it applied.

_{Well I got "THE LETTER" today. :devil:} 

 

_{Duncan Movassaghi assures me in the letter that " You'll be reassured to hear that independent testing authorities have confirmed that there will be no negative impact on engine performance, maximum torque, fuel consumption, noise and CO2 emissions as a result of having this update applied"  Nothing to indicate though that VW think the same thing! :thumbdown:} 

 

_{I'm also assured that "Of course, you won't be charged for having the work completed." That's a weight off my mind then. :clap:} 

 

Unfortunately let down by suggesting that my nearest Skoda dealer is 25 miles away when it's actually 2 miles away! :x 

 

 

 

_{Well I got "THE LETTER" today. :devil:}

_{Duncan Movassaghi assures me in the letter that " You'll be reassured to hear that independent testing authorities have confirmed that there will be no negative impact on engine performance, maximum torque, fuel consumption, noise and CO2 emissions as a result of having this update applied" Nothing to indicate though that VW think the same thing! :thumbdown:}

_{I'm also assured that "Of course, you won't be charged for having the work completed." That's a weight off my mind then. :clap:}

Unfortunately let down by suggesting that my nearest Skoda dealer is 25 miles away when it's actually 2 miles away! :x

Jesus, that font's a little harsh on the old peepers!

Jesus, that font's a little harsh on the old peepers!           

 

Specsavers should see you OK. :nerd:

Yeah; but mytbe he can't find one...

_{Well I got "THE LETTER" today. :devil:}

_{Duncan Movassaghi assures me in the letter that " You'll be reassured to hear that independent testing authorities have confirmed that there will be no negative impact on engine performance, maximum torque, fuel consumption, noise and CO2 emissions as a result of having this update applied" Nothing to indicate though that VW think the same thing! :thumbdown:}

_{I'm also assured that "Of course, you won't be charged for having the work completed." That's a weight off my mind then. :clap:}

Unfortunately let down by suggesting that my nearest Skoda dealer is 25 miles away when it's actually 2 miles away! :x

Ask him to assure you that there will no difference to the torque curve, not just the maximum torque and also that there is no detrimental effect on components e.g. the EGR.

In fact it would be nice of him to provide you with/point you at the independent testing. :)

Edited 31 December, 20169 yr by VAGCF

This is interesting:- "engine needs 300rpm more before delivering peak torque"

http://www.honestjohn.co.uk/askhj/answer/71898/skoda-yeti-diesel-performance-after-emissions-fix

That will likely be linked and quoted now & from now on with a possible typo when it should have probably been '3,000 rpm'.

Edited 3 January, 20179 yr by Offski

The low speed "rattling" might be pulling hard at too low revs, and the DMF is "chattering".

 

Modern high pressure diesels don't pull like the old ones, more like a petrol in some respects. 

Modern VW Group Euro 5 Emissions TDI's were doing what they were doing, the question is will they do the same after 'The Fix', which is New Engine Management 

so that the VW Group can say that the Defeat Device has been removed.

This is interesting:- "engine needs 300rpm more before delivering peak torque"

 

That is a fairly egregious mistake on the part of "Honest" John.  What the fellow who had had the dyno runs done actually wrote was: "there is a difference of about plus 300rpm with the new software before reaching the same start point for power and torque."

 

The dyno graphs were posted in the Yeti Owners Club technical forum.  You can clearly see the power and torque lags at low revs on the graph (green is "before", pink as "after"):

 

 

 

That will likely be linked and quoted now & from now on with a possible typo when it should have probably been '3,000 rpm'.

 

If people believe the mistaken HJ quote about "peak torque" and that it requires "3,000 rpm" more then...well, all I can say is thank heavens for rev limiters.

 

HJ does seem to like leaping for and grasping manfully on to conclusions based on barely sufficient evidence.  You have to admire the confidence with which he declares that this single data set from a single vehicle:  "...explains why so many Tiguan owners were complaining of a 'rattling' noise between 1400 and 1800rpm. They must have been shifting up at the same revs as before the software fix, but at a point where the fix has left insufficient torque."  Yes, John, they must have been doing that, it at must definitely and irrefutably be the truth.  Not just a possible explanation. No no no.  HJ has declared it so.

Agree with all above, but as we only have speculation, it could be the Tiggy people were trying harder to see if there was any difference in performance after being doctored, not driving as they might have done.

Just a possible explanation for the tinkly Tiggies.

Why is there a small peak in torque and power at low revs, before dropping and then increasing smoothly rather than increasing smoothly all the way?

And I don't really understand the comment from the guy saying that there was a 300 rpm increase before reaching the same start point.

Surely as with the run before the fix, torque and power (although low) is being produced from the same start point?

And it's interesting that after the fix that the initial peak for torque and power is greater than before the fix before dropping onto virtually the same curve. Will that feel like a flat spot when driving?

Edited 3 January, 20179 yr by VAGCF

I'm wondering about that dyno graph too, the new software produces virtually the same torque and power as before so there should be very little difference in performance. What does intrigue me though is the fact that although the small peaks at low revs are higher up the rev band on the modified software, the data logging also doesn't start until quite a bit further up the graph on the modified car. Evidence of machine error perhaps?

Ian.

I'm wondering about that dyno graph too, the new software produces virtually the same torque and power as before so there should be very little difference in performance. What does intrigue me though is the fact that although the small peaks at low revs are higher up the rev band on the modified software, the data logging also doesn't start until quite a bit further up the graph on the modified car. Evidence of machine error perhaps?

Ian.

I suspect it was simply the point where the clutch was let out/how abruptly the throttle was pressed.

 

To my mind the map should be identical to the one that's on the car with the "if test then use eco map" bit removed along with the now-redundart eco map

 

At least it explains how mappers have had space for the performance map and the stock map on the ECU at the same time

I suspect it was simply the point where the clutch was let out/how abruptly the throttle was pressed.

 

To my mind the map should be identical to the one that's on the car with the "if test then use eco map" bit removed along with the now-redundart eco map

 

At least it explains how mappers have had space for the performance map and the stock map on the ECU at the same time

I thought on a dyno run that the clutch was fully home before the run started and the throttle was just floored up to peak RPM then the clutch disengaged to allow the transmission to slow down by drag to then allow the programme to work out the flywheel horsepower. 

 

If you have a remap done then doesn't the OEM map get stored on a database somewhere so only the enhanced map is in the car, then if you want to return to standard you connect back up to the diagnostic port and re-flash the original software back onto the ECU?

 

Ian

Big problem with before & after dyno testing is that it's all done at full throttle.

I imagine a lot of the tweaks for the emissions fix will be applied at light/part throttle operation, which is where the car spends most of it's time running, and won't show up on a dyno run.

I thought on a dyno run that the clutch was fully home before the run started and the throttle was just floored up to peak RPM then the clutch disengaged to allow the transmission to slow down by drag to then allow the programme to work out the flywheel horsepower.

 

Yes that's how it's been done when I've had my cars done in the past.

If you have a remap done then doesn't the OEM map get stored on a database somewhere so only the enhanced map is in the car, then if you want to return to standard you connect back up to the diagnostic port and re-flash the original software back onto the ECU?

On the CR diesels at least that's the case, on mine there's only one map on the car at a time. When I go back to standard on mine I have to wait for the handheld tool to upload the original map, which takes a little while.

But I know other ECUs have been able to store multiple maps, and you can use a handheld tool to switch between them.

Big problem with before & after dyno testing is that it's all done at full throttle.

I imagine a lot of the tweaks for the emissions fix will be applied at light/part throttle operation, which is where the car spends most of it's time running, and won't show up on a dyno run.

Agreed, I think the idea behind producing the graph was to show that the updated software doesn't unduly affect the ultimate power and torque output of the engine so as to allay any fears from owners about their car being a sluggish bag of bolts after the update was done.

 

Ian

Those dyno graphs look odd to me.

The small spikes at the lower rev range are unusual, and I thought peak torque was usually reached way before 3500rpm ?

EDIT: Looks to me like something's causing the engine to pull back from 2000rpm ish. Torque starts to rise quickly as you'd expect, then it suddenly dips and doesn't rise again till further up the rev range.

(It's on both before & after graphs, so I'm not suggesting it's a result of the software update)

Edited 4 January, 20179 yr by muddyboots

Why is there a small peak in torque and power at low revs, before dropping and then increasing smoothly rather than increasing smoothly all the way?

Definitely doesn't look right. Something is causing power to be cut. My feeling is it's something to do with the 4wd system, and operating it on a dyno.

Edited 4 January, 20179 yr by muddyboots

Big problem with before & after dyno testing is that it's all done at full throttle.

I imagine a lot of the tweaks for the emissions fix will be applied at light/part throttle operation, which is where the car spends most of it's time running, and won't show up on a dyno run.

And that's why I keep saying to ask for SFC curves; they have to be taken at constant throttle and revs, move to next station, take reading...

Edited 4 January, 20179 yr by KenONeill