We don't normally get the cooling fans coming on even in Summer after parking Yeti 2012. But just recently and since the ECU mod. the fans have been running on for several minutes when the outside temperature is only 9 Deg. C. I know there's an electric circulation pump to move coolant around if the fans do run ignition off, but we seem to get this condition more often now, even before the temperature gauge has reached normal temperature.

 

How do everybody elses fans work? There are no faults showing with a vcds scan.

Hi, sounds like the DPF is doing a regeneration & you switch off before its finished. Mine hasn't had the mod done & I find it doing a regen about every 10 days or so.

Regeneration kicking in perhaps. Made me wonder what the devil was happening when my last Yeti did it the first time and because I only do short journeys nowadays, it's the reason I've just swapped.

 

(Edit - snap :)  )

Edited 15 January, 20179 yr by longedge

If it is a regen, then there is usually a strongish smell accompianing the fans being on.

When you say ECU mod,are you referring to "the fix"?

One of the predicted side-effects of the NOx update was the possibility of increased DPF regens. Perhaps this is evidence of that?

I might find out from tomorrow, mine is booked in for service and, although I didn't tell them when I booked it, I have had the letter from Skoda saying I could take my car in for "the fix" which they may well do when they check with HQ for updates.

Ian

My 170 was in for a service last week and I declined the ECU 'fix'. My feeling is that it's just too early to understand the implications of having it done - especially as it's a one way ticket. They cannot / will not back it out. However they stated that I could have the 'fix' done at a future date if I wish.

Who's to say - the environmental impact of having it done may be even greater if parts wear out and have to be replaced due to increased use and stress that were only ever designed to be used in test scenarios.

When you say ECU mod,are you referring to "the fix"?

 

That's correct! A proper ECU mod tried and tested by many is a Stage 1 remap isn't problematic! Perhaps some are correct about the regen. Yeti hasn't done many miles since having the fix done and perhaps re-gen is a consequence of them applying the fix? Still, they should tell us.  Am I right in thinking a cylinder head temperature sensor triggers fans, which could explain why the cockpit gauge is hardly reading? Some cars use a sensor near the pump for the gauge and a cyl. head sensor for the critical control done by the ECU.

 

If it happens again in the driveway, I will try to rush out with VCDS and see what temperatures it is measuring and read the fan status.  I can also point an IR thermometer at the cyl. head and exhaust.  I've been thinking for a while that a remote reading Ihermometer would be a good thing to tell when the Yeti (and other cars) is regenerating. Ideally a K type thermo with remote wireless display would fit the bill. One curious thing is if the ignition is turned on then off  whilst the fans are running they do not carry on running. 

mine is booked in for service

 

 Be a aware I had a service reminder letter about a cambelt change in which they stated they would check and update any software. If you have had a remap done you would be really pi**ed with that. It might also allow them to do the ECU fix, even if you haven't yet agreed to it.  VAG dealerships love taking control of your car, putting data on their systems and sending you service and sales mail. I never give them an email address.

 

If there was a way to restrict their access to my OBD port for software changes but allow diagnostics I would do it. Somebody come up with an in line OBD dongle! I can fix my OBD port by re-wiring it to only work with a 'custom' male-female connection cable. But then they would't be able to do basic diagnostics without it. Still, it would stop the perps plugging in their dongles, accessing the immobilizer and stealing the car.

That's correct! A proper ECU mod tried and tested by many is a Stage 1 remap isn't problematic! Perhaps some are correct about the regen. Yeti hasn't done many miles since having the fix done and perhaps re-gen is a consequence of them applying the fix? Still, they should tell us.  Am I right in thinking a cylinder head temperature sensor triggers fans, which could explain why the cockpit gauge is hardly reading? Some cars use a sensor near the pump for the gauge and a cyl. head sensor for the critical control done by the ECU.

 

If it happens again in the driveway, I will try to rush out with VCDS and see what temperatures it is measuring and read the fan status.  I can also point an IR thermometer at the cyl. head and exhaust.  I've been thinking for a while that a remote reading Ihermometer would be a good thing to tell when the Yeti (and other cars) is regenerating. Ideally a K type thermo with remote wireless display would fit the bill. One curious thing is if the ignition is turned on then off  whilst the fans are running they do not carry on running.

I have a google app called vag dpf. Along with a Bluetooth obd dongle thing it gives loads of dpf data. Search for it on the App Store. Not available for iPhone.

Check it out it lists engine codes it works with and yours may be listed.

Am I right in thinking a cylinder head temperature sensor triggers fans, which could explain why the cockpit gauge is hardly reading?

As well as being used for reducing coolant temperature, the fans are used to cool the engine bay if a regen is occurring due to the very high temps the DPF (at the back of the engine) will get to.

If my memory serves me correctly, the EGTs (exhaust gas temps), and therefore the DPF, are raised to around 550-600ºC during regen so the DPF gets very hot - if you park up and switch off mid-regen, the fans continue circulating air so the engine bay doesn't cook....

The regen doesn't really affect coolant temperatue - so the fact the fans are running doesn't necessarily relate to coolant temp - in fact I suspect it's very rare the fans are actually needed for reducing coolant temp on a diesel in normal use.

Edited 16 January, 20179 yr by muddyboots

I have a google app called vag dpf. Along with a Bluetooth obd dongle thing it gives loads of dpf data. Search for it on the App Store. Not available for iPhone.

Check it out it lists engine codes it works with and yours may be listed.

Interesting thanks, might have a play with that.

VCDS is great, every bit of live data you could ever want is there, but it's a faff using the laptop if you want to monitor stuff while driving and you're solo. A phone app I can see while it's in the windscreen mount is ideal.

Thanks. Whose BT OBD dongle is it (ELM327 based?) and can you do adaptations and SRI clears like vcds? I will get into the dpf with vcds and see when the last regen was.

I will get into the dpf with vcds and see when the last regen was.

One of the measuring fields is labelled "Km since last regeneration" but the value is in metres (or vice versa).

If you want to tell if a regen is occurring, look at the EGTs. There are 4 EGT fields, two of which provide relevant data, pre- and post-DPF. If a regen is occurring this will shoot up to around 500-600ºC. Unless you're doing a prolonged full throttle run up a long hill, the temps will normally be around half of this, or less if just idling or driving gently.

Edited 16 January, 20179 yr by muddyboots

Thanks. Whose BT OBD dongle is it (ELM327 based?) and can you do adaptations and SRI clears like vcds? I will get into the dpf with vcds and see when the last regen was.

Mine is a vgate icar2 and yes it has to be elm327 based.

No idea what adaptions and sri clears are as I've not had vcds.

The app just gives you the readings and helps you understand what the car is doing and when.

I find it perfect as there's nothing else I've seen which is as simple and straightforward and gives so much info.

O.K I've thought through getting a dongle to use as well as my vcds. I can see that having something to plug in or keep plugged in to use with an Android could be easier to use for fault code reporting and active monitoring. However, I think only VCDS will do adaptations. I'll share how I go forwards:

 

I already have some cheap ELM327 usb wired dongles and was disappointed with their reliability. I contacted the ELM chip suppliers and learned there are many Chinese clones which use the older ELM chip hardware and firmware which can cause lockups and loss of functionality with some softwares. The free software apps even have some work arounds to be more reliable with the cheap clones. I  even got sent some genuine chip samples from ELM. Their firmware code is protected and difficult to copy. It is the luck of the draw if you buy a cheap cable clone and it works or gives problems so I decided to research OBD 2 adaptors that had the faster ELM 16 bit PIC chips with the latest genuine ELM firmware and updateable.

 

There are lots of very cheap vgate icar2s sold on Fleabay sourced from China and I'm sure you can get lucky and and get one that works o.k like yours. Although my experience with these things is you have to go through all the application functions before you find the problems.

 

I have decided to buy a cheap Chinese icar2 from Fleabay AND the more expensive Scantool OBDLink LX  Bluetooth Scan Tool from Scantool Direct u.k. If I sniff it is a fake I will have some come back on the U.K supplier. If the cheap icar2 works for basic diagnostics I shall keep that one plugged in the diags port.

 

Thanks for posting your reply.

Edited 16 January, 20179 yr by voxmagna

Your welcome thanks for your info too.

If my adapter causes me any problems I think I will get the better one you have suggested.