Plateaufunktion der Tempanzeige im KI ausschalten ? | Posts 16+

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Tompalatina wrote:

"Plateaufunktion" means nothing other than that there is an "optical plateau" contained within the otherwise linear curve, so that the same display value (y-axis) is output over a certain range of values of the input (x-axis). In the G4 (and only for it can I speak), it is actually the case that EVERY input value from 72 to 108 in the combined instrument is displayed as "90". Whether the engine gets a little warmer or a little cooler, the needle remains stubbornly fixed at 90.

I agree with all of that up to this point.

Quote:

Therefore, even when the temperature drops to 72 degrees "at the usual plateau," the needle still indicates 90 degrees. If it drops further to 71 degrees, the needle jumps directly to this 71-degree mark, not to the 89-degree mark.

Then, in daily operation, one would often see the needle jump (from 71 to 90° or back), and it would never remain within the 72-89° scale range.
That would, however, be noticeable to any attentive customer.
In the VAG vehicles I have previously driven (G3 AFN, Ibiza 6K GP01 ALH, Polo 9N ASZ, Ibiza 6L BUK), I have not observed anything similar, and the needle only moves approximately twice as fast as the actual temperature changes when it is located between and below the 90° scale.

ulf wrote:

This also applies to the typical plateau: Once the pointer indicates "89", the engine is actually only at 74°C, and the display reading of "85" corresponds to actual temperatures of 72°C, and so on. This works with both increasing and decreasing temperatures

Hi Ulf,

As far as I could observe on the G IV, the needle would simply continue to move upwards to 90° in a timed manner, even without any further increase in coolant temperature, once it had reached 72°. However, I could no longer see it fall to -17° in the stall... Overall, it never fell below > 160tkm, even when it was at 90°. That is, to be clear, only once, when the G62 broke down .

Potentially different software versions in AI?

At least, G VI behaves completely differently in this regard. Unfortunately, I couldn't log in, so I couldn't offer real-world values.

I don't think there's anything "time-controlled" - it's just a subdued control. Therefore, I didn't quite express myself correctly when I said "jumping". There is no abrupt movement - once 72 degrees is reached, the needle slowly continues to move until it reaches 90, even if the coolant is only at 74 degrees at that point.

A drop in temperature during a drive would only be possible in the case where one is making a very long downhill drive from a mountain, for example, an alpine pass descent, during which the engine is almost exclusively operated in "push" mode, and therefore generates very little additional heat. I've never experienced anything like that before...

However, I'm glad that this has finally been fixed in the Golf 6, because this [problem/issue] has always bothered me, to be honest. Therefore, I also tuned the combination!

Tompalatina wrote:

I don't think there's anything "time-controlled" - it's just a subdued control. Therefore, I didn't quite express myself correctly when I said "jumping". There is no abrupt movement - once 72 degrees is reached, the needle slowly continues to move until it reaches 90 - even though the coolant may only be at 74 degrees at that point.

So, when I measured it with the Polo, I used a potentiometer as a replacement for the water sensor and VGCOM.
For example, this allowed me to see that at real 60°C (according to Lappi), the needle was already at 70° etc.
Only leaving the left pedal at 50° is correctly displayed, above that the advance continuously increases, until at approximately 75° the pointer actually reaches 90.
Above approximately 105°, the process continues similarly: once the pointer detaches from the 90, it moves quickly upwards, returning to the correct position around 130°.

However, the pointer can be permanently {STOP} at any position by adjusting the potentiometer. Only between approximately 75 and 105°C is the position of the potentiometer irrelevant.

Quote:

A drop in temperature during the journey would only be possible in the case where one undertakes a very long downhill ride from a mountain, for example, an alpine pass descent, during which the engine is almost exclusively operated in a "push" mode, thereby generating very little additional heat. I've never experienced anything like that before...

Me neither - just now, when the engine's RPM was around 75, even though the needle was just at 90.
Subsequently, during the downhill push, the needle quickly returns to the 50 mark.

Respect, Ulf, I haven't delved into reverse engineering of my car this deeply before .

BTW, in the wild, my experience shows that the behavior of G IV differs from G VI.

Tompalatina wrote:

By the way: Yesterday, I drove my Golf for 800 km, with an outside temperature always below 0 degrees. In these conditions, the needle never reached 90. The water temperature consistently ranged between 75 and 85 degrees.

Hello Tompalatina,
hello everyone,
I'm interested (see also /viewforum.php?f=29).
Sofern, ich bisher davon ausgegangen bin, dass mein Thermostat defekt ist, da ich eigentlich nie über 80°C erhalte (gemessen per OBD), zeigt die KI die bekannten 90°C an.
After your previous statement, I am now wondering whether my thermostat is actually faulty, or whether the opening temperature of 87°C causes the "water" temperature at the measuring point to be just below 80°C.
Now, my absolute "honk" question: At which point in the water cycle is WT measured?
But definitely before the water flows into the engine (where the G62 or the temperature sensor on the radiator is located, I understand), I recently replaced both of them) and not in the place where the hot water enters the radiator.
Can/should an intact thermostat (opening temperature 87°C) actually set 87°C WT before entering the engine? Or does opening at 87°C result in WT <87°C upon entering the engine?
haithamina
My AI is exhibiting the behavior described by Ulf: slow startup until the needle is vertical (90°C). In this case, the AI is ahead of the actual temperature. However, it's not the case that the display immediately shows 90°C once the temperature reaches 72°C / the beginning of the plateau, but there is also the KI value of 80°C (which is then actually close to 70°C).

The above "Honk" question was probably not so trivial after all.
Otherwise, a clever tinkerer would have quickly responded.
Or, perhaps they intended to educate me through self-research. That worked: http://www.kfztech.de/kfztechnik/motor/kuehlung/wasserkuehlung.htm explains the topic of cooling circuits very well. However, I am still not sure when/where the KI or MSG measures the temperature for the coolant. The G62 is located at the back of the 3BG, at the bottom of the engine block, and this also provides me with the value measured via OBD of 78°C and the value for the KI. I suspect that this is the temperature. Coolant before entering the engine is.
Is this correct?
The second temperature sensor is located at the bottom of the radiator and provides the value for what/whom? In any case, also the value of the cooled water after passing through the cooler in the large circuit.
Is this correct?
If so, I find a WT of 78°C in winter under partial load to be acceptable, and my thermostat could also function normally.
haithamina

ulf wrote:

...But the pointer can be permanently(!) stopped at any position by adjusting the potentiometer. Only between approximately 75 and 105°C is the position of the potentiometer irrelevant.

Make sense when you look at the characteristics.
X is the temperature (target value, not measured) and Y is the desired value for the
Stepper motor control.