General tuning question - when do values in cells become effective?

[Gordon-0]

so I realize the title is somewhat vague but for example, in the fan settings, 0->1 is at 44%, and 1->0 is at 40%.
does this mean that AT 44% the fans will go to state 1, or ABOVE 44% they will go to state 1?
same with 1->0, is it AT 40% or below 40%?

edit:
the reason I ask is that the stock fan control goes from 43 at 93c to 45 at 95c then from 80 at 109c to 90 at 111c.
Im making a towing tune to try and get the fans to come on sooner and hopefully keep the temps in check, and I just want to make sure I understand the logic

hopefully this makes sense and is a simple question to answer.

[blindsquirrel]

Seems like it would also be pretty easy to test yourself, by logging all the related stuff.

[Cringer]

so I realize the title is somewhat vague but for example, in the fan settings, 0->1 is at 44%, and 1->0 is at 40%.
does this mean that AT 44% the fans will go to state 1, or ABOVE 44% they will go to state 1?
same with 1->0, is it AT 40% or below 40%?

edit:
the reason I ask is that the stock fan control goes from 43 at 93c to 45 at 95c then from 80 at 109c to 90 at 111c.
Im making a towing tune to try and get the fans to come on sooner and hopefully keep the temps in check, and I just want to make sure I understand the logic

hopefully this makes sense and is a simple question to answer.

It's overly complicated....but not too bad....
https://forum.hptuners.com/showthrea...ll=1#post52393

[blindsquirrel]

screenshot.24-04-2024 20.00.41.png

In da picture...

So if 0->1 is "44" (whatever that means, for now), then at 43/199.4F it will be still off, at 45/203.0F it will be on, and the actual switchpoint will be somewhere between 199.4 and 203.0. Does it really make a difference to anything in the whole wide world if that happens at 201.2 (at 44) or 201.3 (above 44)?

Further, since 1->0 is "40", and the lowest value in the table is 40, and this vehicle doesn't have an issue with 'fans turn on and stay on forever until the key is shut off' (I'm assuming, it's a stock '09 Silverado 5.3) I think it can be drawn that it happens AT 40, not below, because it can't get to less than 40.

[07GTS]

hope this helps in some way, a fan on is number above state 0-1 value and a fan off is value below state 1-0 value

[Alvin]

Good explanation.

[Gordon-0]

Thank you everyone that is helpful. The next thing I noticed when logging is that the coolant temp gauge shows 210 when the ECT value in VCM Scanner is much lower, like 185 for instance. Is there a way to have the gauge report correctly, or is this beyond what HP tuners can do?

There's a table to allow you to calibrate the fuel gauge, but I don't see anything for the temperature gauge.

[Cringer]

Thank you everyone that is helpful. The next thing I noticed when logging is that the coolant temp gauge shows 210 when the ECT value in VCM Scanner is much lower, like 185 for instance. Is there a way to have the gauge report correctly, or is this beyond what HP tuners can do?

There's a table to allow you to calibrate the fuel gauge, but I don't see anything for the temperature gauge.

The gauges on most vehicles are computer controlled dummy gauges designed to control the driver, not report accurate numbers. Trust the HPT scanner.

[blindsquirrel]

My oil pressure gauge has a needle that will sweep the full range and everything like a real gauge but in use it only has two positions, zero or 40psi.

[Gordon-0]

So for anyone who finds this and is also curious, the values in HP tuners for a E38 ecm are just endpoints of a line, so if you want a "thing" to happen at a value of "50", but you program 40 in one cell and 60 in the next cell, the "thing" will happen at whatever value is between those two cells... Basically the ECM figures it out. Said another way, if you wanted to have a gauge sweep from 0-100% when a value went from 20-80, as long as the sensor is fairly linear you only need 2 cells to control it correctly.

The reason that your fuel gauge has so many cells is to correct for inconsistency in the sweep in certain areas where - for example - 0.1v difference corresponds to 1% fuel drop at one point, but at the other end of the gauge it may be 0.2v = 1% or something.

I made all the values above up, but the point is, the actual values in the cells are not as important as the graph they describe.