Hi, I have a 2015 L83 with 6L80E swapped into a '79 CJ7.
It is running great but I cannot get the fan to work. I am using the Chrysler PWM module and a couple of 10" fans.
I have done plenty of GEN3/4 swaps before and have always used discrete fan control so I am not sure my settings are correct.
Would be grateful if anybody can give me some input !
Attached is the current tune file and log from testing the fan control.
Tried a bunch of different settings but just cant this to work. Powering the control wire to the Chrysler PWM module turns the fans on so it is not an electrical issue. Goint to try and up the PWM frequency and see what happens. I see people have set the frequency to 1200hz and actually run a on/off relay as well.
Last edited by thunderbolt; 06-27-2021 at 02:51 PM.
First off, what kind of fans are you using?
ECM table 18170 your desired coolant temp is set to 383 degree across the board.....try something more realistic and see if that changes anything.
How come I missed that!! I was thinking this was in F and not in C but I see now that settings on my computer is in C so 195C is extremely high. Going to try this tomorrow.
Fans are generic cheap 10" fans because that was all that was available to me right now. Goint to switch to some SPAL fans or similar soon.
Ya, hopefully that does it!Originally Posted by thunderbolt
How come I missed that!! I was thinking this was in F and not in C but I see now that settings on my computer is in C so 195C is extremely high
Fans are generic cheap 10" fans because that was all that was available to me right now. Goint to switch to some SPAL fans or similar soon.
Sorry but have been busy for a couple of weeks. I have the fans running now, but they run all the time or not at all so still a problem.
Setting the desired temperature got them working but they run 100% at 50ish F.
I am kind of confused regsrding the State vs desired table and the Output control vs state tables. I looked at 2009 Corvette file that used PWM Electric fan settings.
State vs desired was all 0's and Output control vs state tables was all 1's. With these settings the fans run 100% all the time.
If I change output vs state to 01111 the fans starts running as soon as the engine starts and temps are 50ish.
I have all 0's in the desired vs AC table ( no AC on this car).
Triat a ton of different settings....what am I missing?
Upload your current calibration. You say they run 100% when the engine starts and coolant temp is 50 or above?
Have been testing a little bit today and they are running 100% as soon as the engine has been running for a few seconds. Dont actually think it is temperature related at all but is leaning towards this having to do with AC control which I dont have. If you look at the short log attached you can see that the ECM is commanding 100% right after startup. With KOEO they do not run.
I think my AC theory is not correct after all. Logged the AC PID's and they are all zero so as far as the ECU is concerned the AC is off.
I also see that right after startup Desired Fan speed goes to 9.8% and a couple of seconds after the fan goes to 100%. I just dont see any logic in why this is being commanded like this.
Does the ECM set any DTCs? It shows desired at 9.8% but fan is running at 100%. If you have a current DTC, sometimes the ECM will kick the fans on 100% as a limp home mode engine proteciton.
Also, your ambient temp reads -40, could you rig up a sensor or resistor to get it closer to a normal number, might be making the ECM think something is wrong and kicking fans on a a precaution.
No DTC's. Oil temp and ambient temp are showing -40 because they are not wired in and all DTC's for these are turned off so that should not be an issue?.
Did another log with all available temperature PID's for engine and transmission and nothing unusual as far as I can see. Was hoping to see one sensor maxing out somehow....
I cannot see any parameters that will command 100% unless there is something overriding the fan settings because it should only go to 90% regerdless. AC is is the only thing I am aware of that can do this but according to the previous log the ECM sees that the AC is off. But maybe there are something that is not defined in HPT that is doing this? Running version 4.4.4
TB I have an L83 LT in my JK Jeep. When I first started it the fan (2017 SS Camaro PWM unit) ran at 100% after about 3 seconds of startup. It was the AC not plugged in to the pressure switch. After that it worked great. Understand you may not have AC so you need to go into the fans area and get rid of the AC code that detects that.
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