[T6_measured] Winter specialities

[mmi]

Spot the winter specialities:​

​

​

Spoiler: Hint 1

Missing the AdBlue fill amounts

Spoiler: Hint 2

Elevated engine revs (no, it's not regenerating the DPF) as continuosly monitored by

[T6_measured] Monitoring DPF regeneration, DPF condition, EGR operation

Here's another approach for T6 DIY enthusiasts - taking advantage of very popular Carista OBDII-reader device - combined with an Android app. Ingredients: T6 EU6 engine: CXEB,CXEC,CXFA,CXGA,CXGB,CXGC,CXHA,CXHB. Carista OBDII device (also other generic OBDII (ELM327) devices will work) for...

www.t6forum.com

 

[mmi]

Fuel filter heating at freezing temperatures​

Spoiler: SSP 514

Page 37 in

https://procarmanuals.com/pdf-online-vag-ssp-514-new-ea288-diesel-engine-family/

Spoiler: Summer

Pending... warmer weather

Meanwhile an old log of a warmer day...

 

[mmi]

Reserved.... EGR, EGR cooling, EGR bypass...

---

❆❆ EGR normal cooling and EGR cooler bypassed​

From 0 to 200 seconds reported EGR position > 0% thus EGR cooler bypassed. This cooler bypass happens always after engine start, even in summer conditions. [EDIT: 20.4.2024]

From 200 to 1100 seconds reported EGR position < 0% thus exhaust recirculation through EGR cooler.

From 1100 to 1800 seconds reported EGR position > 0% thus EGR cooler bypassed (also seen from 0 to 200 seconds).

The transition seems to take place somewhere at 0....+5 °C.

EGR position transition at moderate temperatures (0..+5 °C)​

---

❆❆❆ EGR fully closed - no exhaust recirculation​

Transition from operating mode EXHAUST RECIRCULATION WITHOUT COOLING (EGR position > 0%, EGR cooler bypassed ) to mode NO EXHAUST RECIRCULATION (EGR position = 0%) seems to take place somewhere at ambient temperature of –15...–20 °C In the picture below from 900 seconds onward.

EGR position transition at fairly cold temperatures (-15..-20 °C)​

EGR Cooler input and output temperatures - EGR cooler bypassed​

EGR cooler bypassed from 65 to 900 seconds.
EGR closed (no recirculation) from 0 to 65 seconds and 900 to 2000 seconds.

The above zoomed in y-axis​

Spoiler: -28 °C

Engine coolant and cabin preheated with Webasto auxiliary heater - unfortunately it doesn't warm up the engine oil.

 

[mmi]

Edited 9.7.2024

Charge air cooling & cooling pump activation​

Above: At colder temperatures the cooler pump is running at "regulated" state both in DPF regen and in engine's normal running. However, more cooling is provided when DPF regen is NOT in progress.

Below: At warmer temperatures the cooler pump is running at maximum rate (95%) when DPF regen is NOT in progress.



Notes:
Cooler pump activation 10% = pump is not running.
Cooler pump activation 95% = pump is running at maximum rate.
The values <10% and >95% are used/reserved for fault detection.

 

[mmi]

Reserved.

 

[Dav-Tec]

I'd be interested to know if there's a way to code the cluster so I doesn't display the adblue menu at all

 

[n10n]

Reserved.... EGR, EGR cooling, EGR bypass...

---

Very nice summary of all EGR modes, well done

 

[mmi]

Very nice summary of all EGR modes, well done

Thanks - as I was preparing the next batch for "charge air cooling" from the same data as above with transitions in the middle, I noticed that there is a heavy dependancy on the EGR operation - well, it shouldn't have been a surprise as the emission reduction is on the first priority on these engines.

 

[n10n]

I'm sure @mmi has this well covered but I think this will fit this thread anyway - T6 CXEB AdBlue in cold temperatures.

• Ambient temperature at -17°C
• AdBlue tank temperature starts from -12.2°C, has not had enough time to cool down to ambient
• AdBlue heater consumes pretty stable 2.5A
• At about 1170s, AdBlue tank temperature reaches -11°C and injection starts
• -11°C is exactly the freezing point of AdBlue - there's really no headroom here, injection starts immediately when it can
• Not sure what the injector activation peak at 870s is - maybe a self test for frozen injector?
• Also not sure why the heating current pulsates but only after the injector activation peak

 

[mmi]

Not exactly a winter speciality - but easier to spot when cold.


@1370 seconds of the log.

Dash coolant temperature gauge (red) vs. actual engine coolant temperature (green)​

Engine and cabin preheated, thus coolant at +30 °C at engine startup.



As explained in VW SSP 311 The Transporter 2004 Electrical system



Also mentioned:

Coolant Temperature Readout

Today, I noticed that the coolant temperature gauges were out of sync! The analogue one didn't move off zero for several minutes and the digital one appeared to lag behind the analogue gauge.....so when the analogue gauge eventually got up to 90 degrees, the digital gauge was only reading 60...

www.t6forum.com

 

[mmi]

AdBlue heater consumes pretty stable 2.5A

I believe the mentioned heater is identified on OBD2 socket as IDE03134, which indeed seems to draw quite stable 2.5 A.

But isn't there a second AdBlue heater (IDE03133), actually more powerful - drawing almost 10 A at -30 °C.

 

[n10n]

I believe the mentioned heater is identified on OBD2 socket as IDE03134, which indeed seems to draw quite stable 2.5 A.

But isn't there a second AdBlue heater (IDE03133), actually more powerful - drawing almost 10 A at -30 °C.

Indeed. I just didn’t happen to have that one in the recorded set. I think one of the heaters is the injector and one for the tank - don’t immediately recall where I read that, one of SSP’s possibly.

EDIT:

 

[n10n]

I think one of the heaters is the injector and one for the tank

I think I picked the injector heating from this one - injector has a coolant jacket. While mostly intended for cooling and not mentioned in SSP I think it also works to prevent reducing agent icing in very cold temperatures.

 

[mmi]

Indeed. I just didn’t happen to have that one in the recorded set. I think one of the heaters is the injector and one for the tank - don’t immediately recall where I read that, one of SSP’s possibly.

EDIT:
View attachment 229669

Thanks.
VCDS data suggests the following:
IDE03133 Reducing agent metering system heating circuit 1
IDE03134 Reducing agent metering system heating circuit 2

 

[n10n]

Thanks.
VCDS data suggests the following:
IDE03133 Reducing agent metering system heating circuit 1
IDE03134 Reducing agent metering system heating circuit 2

The interesting thing is that last fall when it wasn't cold yet I had both of them measured for some time and I noticed IDE03134 having some current. For example this one from Sep 11:

                                                                                              unit   count      ts_0      ts_n           val_0           val_n             min             max             avg          median      std_dev

CAN3.advanced_measuring_values_engine.IDE03133_adblue_heating_1_current                          A    7769    2.2304 3631.7458          0.0000          0.0000          0.0000          0.0000          0.0000          0.0000       0.0000
CAN3.advanced_measuring_values_engine.IDE03134_adblue_heating_2_current                          A    7769    2.2304 3631.7458          0.2800          0.3120          0.2180          0.3740          0.3055          0.2960       0.0320
CAN3.advanced_measuring_values_engine.IDE03135_adblue_tank_temperature                           C    7769    2.2304 3631.7458         18.1000         24.2000         18.0000         24.2000         22.0645         22.8000       1.8671
C

Although IDE03134 in this one has only some hundreds of mA it's still something and clearly tank temperature is plenty high. Unfortunately later I removed IDE03133 to make room for more interesting things so I don't know if it generally holds that IDE03134 will heat before IDE03133 - would kind of make sense, the line would be more likely to freeze on cold nights while tank freezing will take seriously cold for quite some time.

 

[mmi]

Although IDE03134 in this one has only some hundreds of mA it's still something and clearly tank temperature is plenty high. Unfortunately later I removed IDE03133 to make room for more interesting things so I don't know if it generally holds that IDE03134 will heat before IDE03133 - would kind of make sense, the line would be more likely to freeze on cold nights while tank freezing will take seriously cold for quite some time.

Also my impression is that IDE03133 needs serious cold to activate. Also originally had excluded that because it seemed to be a null channel. As the weather is now warming a bit need to keep on monitoring.

Yesterday it was only -11 °C and the IDE03133 (below heater 1) was active.
The heater currents were sampled at 3 second intervals so probably missed quite a few pulses you observed.

Also not sure why the heating current pulsates but only after the injector activation peak

No AdBlue was injected before 1190 seconds, which is different in warmer weather (e.g. below)

[T6_measured] NOx emissions, AdBlue consumption, DPF regeneration - Before and after ECU update

Introduction An update campaign for T6 EU6 diesel engines took place in 2019-20. Affected engines were on van of model years MY16-MY18, including some of MY19. For M1 class (passenger carriers, VIN WV2...) the update was an official recall. For N1 class (VIN WV1....) the update was not...

www.t6forum.com

 

[n10n]

No AdBlue was injected before 1190 seconds, which is different in warmer weather (e.g. below)

This is very interesting!

My sample earlier started the injection pretty much at 1190 seconds as well but the adblue temperature was much lower. So I guess the injection start is time -based rather than temperature based when it’s cold enough.

Hard to think why though… the only explanation I can offer would be to limit dependencies - the system can be perhaps slightly more reliable if temperature sensor fault will only affect heating. Hmm… or maybe it would be too easy to fake temperature sensor reading and disable adblue if the injection would depend on the temperature? VW must know many people would simply buy 5$ adblue bypass temperature sensor if such a thing would be possible.

 

[mmi]

Quite a few temperature sensors we have got - and there are quite a few more. And, please note the AdBlue level
The snapshot below was taken after some serious engine preheating by Webasto and 10 seconds after starup.

[*]Ambient temperature at -17°C
[*]AdBlue tank temperature starts from -12.2°C, has not had enough time to cool down to ambient

Thanks for that - that's a good explanation for my only -13.4 °C AdBlue when ambient was -26 °C. Had already started to wonder if there was something wrong in my measuring setup. The van was driven 10 hours before - stopped then with AdBlue at -10.2 °C. Of course I was here expecting to see the AdBlue be at/around ambient temperature. I think it must be the energy "released" when AdBlue changed from liquid to solid (at -11 °C) which had resisted quite some time the temperature drop at freezing point.

 

[n10n]

Of course I was here expecting to see the AdBlue be around ambient temperature. I think it must be the energy "released" when AdBlue changed from liquid to solid (at -11 °C) which had resisted quite some time the temperature drop at freezing point.

Yes, I was also little bit surprised to see AdBlue temperature quite a bit above ambient temperature. It might ofc also be the sensors are really only ”accurate enough” in their nominal operating range - for example your exhaust temperature sensor reading -36.7° does not really sound believable either in ambient -26° (except if caused by a pressure change right after engine was started.) I believe the sensors must be manufactured to withstand the toxins they’re supposed to measure, accuracy outside of nominal range might not be important / cost effective.

 

[mmi]

Yes, I was also little bit surprised to see AdBlue temperature quite a bit above ambient temperature. It might ofc also be the sensors are really only ”accurate enough” in their nominal operating range - for example your exhaust temperature sensor reading -36.7° does not really sound believable either in ambient -26° (except if caused by a pressure change right after engine was started.) I believe the sensors must be manufactured to withstand the toxins they’re supposed to measure, accuracy outside of nominal range might not be important / cost effective.

View attachment 229844

Yes, obviously the exhaust temperature sensors are not too accurate (at least) outside their normal working envelope. The others actually seem to be surprisingly consistent.
Below a VCDS capture after having the van parked at steady -27..-28 °C for 26 hours. It seems there is not much residual heat.
The exhaust temperature sensor mentioned above is the IDE07716 below.



Another one captured on a warmer day.