My radiator fans won't turn on in my stock 2014 Caprice 6.0L. I'm wanting to command both fans on to troubleshoot the problem. But when I look at VCM Scanner's fan controls I see options to turn on fan 1, fan 2, fan 3, fan speed, and ac clutch. Because my fans aren't working, I'm not sure what combination of these settings to use?
For example, would fan 1 on, fan 2 on, and fan speed on and 100% work? I only have two fans, what does fan 3 setting or AC clutch do?
Do you have a 3-relay system where both fans run in low speed and then both fans in high speed? Or 2-relay where each fan runs independently and only at full speed?
The scanner doesn't know which setup you have either, it only knows the (potentially) available output pins in the ECM. You probably only use Output 1 for both fans in low speed, and then Output 1 + Output 2 for both fans in high speed. Look at your wiring diagram and trace out what happens when each pin is grounded.
post your tune file. if you cant command the fans on with the scanner, its possible you may have a wiring issue. Is the setup aftermarket?
Here's my tune file.
As far as relays go, I don't believe this car has any for the cooling fans. They're controlled by a PWM fan controller that gets constant hot and ground and is controlled by a smaller signal wire that goes straight to the PCM. As a sort of control to start troubleshooting I've been trying to figure out a way to command both fans on 100% duty cycle but I'm not really sure how to do that through the scanner. I've tried turning everything on that screen to ON and set speed to 100% but not sure if that's the best way to do it.
I've also attached screenshots of the fan control settings, and my DTCs. I have a few but they don't look like they'd be fan related. Most here have more experience than me so I'll post them just incase there's something I'm missing.
Oh, you just use the 'Fan Speed: On' button and then increase the %, ignore the others. The 1/2/3 stuff is there because the ECM supports 3 output pins, but only one is being used, and it's variable duty cycle PWM instead of on/off.
By your Desired vs ECT table it only turns the fan on at minimum speed at 215*F (below 10% commanded is 'off', more than 90% is full speed).
Good to know! I was pretty confused but that explation makes perfect sense, thank youOriginally Posted by blindsquirrel
Ah cool, nice to know. After I figure out this fan issue I'll play around with these settings a little.
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