My primary cooling fan comes on at 170 degrees and doesn't turn off. The on/off temps in my BIN are set to 209 on/ 200 off. I have these temperatures set with both AC on and off.
While data logging with Tunerpro, it shows the temperature at 170.1 when the fan turns on and the flag is set for "requested on" by the ecm.

What am I missing that controls the function of the fan in 6e?

 

98.3c is the on 93.3 off ? But CTs shows 170f and they kick on ?

 

Hey Brian, yep all temps (ac on or off) are set to 209 on and 200 off. The primary fan comes on at 170.1 like clockwork.

This happens at idle sitting still or at cruising speeds. Tunerpro shows that the fan is requested when the temp shows 170 on the datalog.
I still have the same 195 thermostat. I had noticed that by the time the dash gauge reached 190 or so, that the primary fan was already on. It turns off with the key and if I let it cool down below 170 and restart it, the fan is off until 170.1 indicated.

 

fand temperatures

 

You can see the temp and duty cycle here.

 

If you want to send me the bin I’ll load it on tuner cat $6e . I’d think if it’s the same I’d think the ecm is messed up.

 

Fan requested and ac is off.

 

Will do, you want a email? I hope that its not the ecm. This is the one that i got from you because my oem 165 would not connect to my laptop to datalog. This connects on the first try everytime.

 

Yes please shoot me a email, I have 2 165s right now. If the data looks right I’ll send you one .

 

Done, I sent it to the yahoo address that I had.

 

Do you have a (low temperature) fan switch connected to the A/C high pressure (or cooling fan) switch input pin (D11)?

In this log from Felix's car, the fan activation is clearly being controlled below 35 mph by the switch input rather than the (significantly hotter) coolant temperature settings: https://datazap.me/u/tequilaboy/feli...0298&hg=8-9-35

Relevant parameter settings from Felix bin 17:
SCALAR: Maximum MPH for switch input 35.00 MPH
SCALAR: Fan Post control timer (minimum run time after deactivation conditions fulfilled) 10.00 Seconds
SCALAR: Fan Duty Cycle if MPH < Maximum and switch input 99.61 %DC

SCALAR: Fan 1 Turn On (A/C On) 200.30 Deg F
SCALAR: Fan 1 Turn Off (A/C On) 194.90 Deg F
SCALAR: Fan 1 Turn On (A/C Off) 200.30 Deg F
SCALAR: Fan 1 Turn Off (A/C Off) 194.90 Deg F

TABLE: Cooling Fan Duty Cycle vs. Coolant Temp øF

Deg F Fan % Duty Cycle
%
306 99.61
284 99.61
262 99.61
241 99.61
219 99.61
198 99.61
176 99.61

 

It’s shown normally open in the bin

 

I currently have gm fan switch 3053190. 200 on 185 off, I believe. The scan shows the fan requested at 170.1 and it never turns off. My bin is set up just like you have listed. Tunedperformance (thanks Brian) sent a 165 ecm to me to try. The primary fan comes on at 180 displayed in the DA List . Fan requested, no ac requested. Then around 195, the secondary fan comes on. I left it to idle for 30 minutes and the fans never turned off. The indicated temperature on tunerpro stayed between 185 and 195.

 

It would appear that your fan switch is closing at a lower temperature than expected.

Here's another 3rd gen log with the fan being activated via the switch input at a relatively low temperature (around 177 °F). Note: I had set the cooling fan duty cycle scalar in the bin to 95% but kept the cooling fan duty cycle table at 100% in order to better see which input was driving the bus in the event of overlapping control.

You can see the (inverted) cooling fan request signal along with the resulting 95% duty cycle here: https://datazap.me/u/tequilaboy/cama...1991-1803-2181

You could always unplug the fan switch if you wish to run the fan exclusively from the coolant temperature sensor input and duty cycle table instead of the switch with a loss of redundancy.

 

You are absolutely correct. I depinned D11 and the secondary fan does come on early and the ecm is back to controlling the primary fan. I'll just grab a new fan switch and go from there. Also, both fans come on with the AC on and indicated in the Tunerpro scan.

The solution was so simple.

Thanks for the help guys!