[T6_measured] Winter specialities

[n10n]

Thanks for that - that's a good explanation for my only -13.4 °C AdBlue when ambient was -26 °C

Actually, here’s another thought:

AdBlue will be ice at that temperature. I don’t know where the sensor is exactly but I imagine it would be near the bottom of the tank and submerged so surrounded by ice. Ice is not the best thermal conductor so it would act as an insulator and slow down the temperature drop.

I failed to quickly find data on ice surface vs core temperature data so just a hypothesis.

 

[n10n]

And, please note the AdBlue level

Here's the internal CAN value stats regarding AdBlue, ambient temperature and advanced measuring values I had over AdBlue on a cold day (same dataset as in post #9). Actually there's still some others in CAN but not any interesting values and I suspect they might not work. Instead of IDE10249 Reducing agent fill level sensor: act. value (mm) CAN has percentage remaining. This seems to retain it's value in cold days - I think 0mm is just interpreted as invalid and previous value is used instead.

                                                        unit   count     ts_0      ts_n           val_0           val_n             min             max             avg          median      std_dev
ambient_temperature                                        C    8789  13.5312 1771.8081        -17.5000        -17.0000        -19.5000        -13.5000        -17.5762        -17.5000       1.4552
adblue_status                                                   1769   2.3667 1771.2494          1.0000          1.0000          1.0000          1.0000          1.0000          1.0000       0.0000
adblue_refill_min                                          L    1769   2.3667 1771.2494          0.0000          0.0000          0.0000          0.0000          0.0000          0.0000       0.0000
adblue_refill_max                                          L    1769   2.3667 1771.2494          0.0000          0.0000          0.0000          0.0000          0.0000          0.0000       0.0000
adblue_remaining                                           %    1769   2.3667 1771.2494         63.0000         63.0000         63.0000         63.0000         63.0000         63.0000       0.0000
adblue_range                                              km    1769   2.3667 1771.2494       5500.0000       5500.0000       5500.0000       5500.0000       5500.0000       5500.0000       0.0000
IDE03134_adblue_heating_2_current                          A    3981   2.2178 1771.8054          2.5590          2.4960          0.3270          2.6050          2.4940          2.5270       0.1622
IDE03135_adblue_tank_temperature                           C    3981   2.2178 1771.8054        -12.2000        -10.2000        -12.2000        -10.2000        -11.0544        -11.2000       0.4561
IDE11219_adblue_specified_injection_quantity            mg/s    3957   2.2975 1771.8854          0.0000         41.0000          0.0000         41.0000         13.9985          0.0000      19.4031
IDE07797_adblue_injector_activation                        %    3950   2.3775 1771.1649          0.0000          0.0000          0.0000         84.9500          1.6209          0.0000       5.9271

 

[n10n]

Usually I run CANEdge only on ignition. However, last night I left it on throughout the night in an attempt to get a capture of CAN in deep sleep - to figure out if anything goes out there or not. Well, turns out my constant querying kept drivetrain CAN (BCM + ECU) on all the time. So, Advanced Measuring Values can be queried fine when van is in deep sleep. For example, here's my exhaust temperatures of 10 minute snippet 6.5hrs into the test

                                                        unit  count       ts_0       ts_n           val_0           val_n             min             max             avg          median      std_dev
IDE04090_G235_exhaust_temperature_1                        C   1369 23582.8822 24130.3047         -4.0000         -4.0000         -4.5000         -3.8000         -4.0716         -4.0000       0.1794
IDE04090_G448_exhaust_temperature_2                        C   1369 23582.8822 24130.3047        -13.0000        -13.8000        -13.8000        -12.5000        -13.2172        -13.0000       0.3708
IDE04090_G495_exhaust_temperature_3                        C   1369 23582.8822 24130.3047        -14.5000        -15.3000        -15.3000        -13.8000        -14.6014        -14.5000       0.2935
IDE04090_G648_exhaust_temperature_4                        C   1369 23582.8822 24130.3047        -16.8000        -16.8000        -16.8000        -16.0000        -16.4622        -16.8000       0.3951

On to the winter specialties... having the CANEdge recording all the time it recorded my webasto engine + cabin preheating and start sequence. So, here's some data plotted out - the timestamps are normalized to start from 0.

• Right at the start aux heater gets remote start command (4-5 in flags)
• Aux heater water pump is turned on immediately (8-9 in flags)
• Aux heater temperature starts to rise pretty linearly
• Main coolant temperature rises also but little bit slower
• Aux heater temperature reaches 45°
• At this point aux_heater_water_in_temp flag goes up (22-23 in flags)
• AC fan is turned on first at 8% but increasing speed slowly
• One of engine coolant circuits shows interesting moves, I think related to opening the small water circuit to the AC heat exchanger
• Finally, I operate driver door locks (20-21 in flags)
• Followed by starting (16-17 in flags)

Interestingly, aux heater combustion flag only goes up after engine has been started. There's also few other flags picked up here I don't try to figure out right now... enough for one night