Type 4 Fan Control

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UNISA JECS
 

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Joined: Wed Jun 04, 2008 3:48 am
Location: USA Socal

Type 4 Fan Control

Post by UNISA JECS »

Haven't seen to much info on "Fan Control" but here are some finding I found messing with my car.

Fan Temp Band 3 Active appears to control fan activation while setting idle in neutral and for my car factory setting is 100 degree, now I have wiggle room to drop that temp down to 95 degrees but if I want to go lower I have to drop Fan Temp Band 2 Active something lower then 95 like i.e. 90 so I can drop Band 3 Active lower and so forth

I also have a bit of findings on the other numbers in the grid that appear to also turn on fans i.e. both LEFT and RIGHT FANS or just the LEFT FAN but i'll have to do a video or a log of this, but i'll start with this info and maybe make the Fan Control make better sense.
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Here is a picture of my setting to have my fans kick on at 85 Degree at idle/neutral



Here's a video on the Fans Activating
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https://youtu.be/6eL9BdBwItc <<<<<CLICK LINK TO PLAY VIDEO
Attachments
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Matt
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Re: Type 4 Fan Control

Post by Matt »

Fan control info is in the feature pack document (Page 11)
https://www.nistune.com/docs/Nistune%20 ... k%20V1.pdf

There are actually two different fan control routines in Nissan ECUs (one for single fan, and the other for fuel fan). Which routine gets used is determined by a tickbox (available in some ECUs) in the feedback flags

From the document if you view as HEX then you can see the 'bitmask' settings for SR20DET:
02 Fans off
22 Low fans on
33 High fans on
There may be other numbers different to this (additional bits) but basically 2x = Low, 1x = High as bit mask settings
It may be the case you have found that the values also change if neutral or not
15dec = 0F in HEX Fans off
63dec = 3F in HEX Low + High fans on
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