PWM fan
11-03-2017, 05:13 AM
#1
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PWM fan About to wire up the following and would like to confirm my approach is correct:
Using following
E38 ECM
Ford MKVIII fan (2 speed fan)
fan controller (note part is the same for corvette, fords, crossfire and mercedes SLK320)
Wire from Pin 58 on the X1 connecter to the sense wire on the controller plug and thats it (besides programming the ECM, controller wires to power and ground plus to the fan)?
The reason I ask is diagrams show pin 58/green wire (which is what I have) as a low speed cooling fan relay control. plan is to wire the controller to the high speed side of the fan and using PWM to vary the fan speed.
Thank you.
Using following
E38 ECM
Ford MKVIII fan (2 speed fan)
fan controller (note part is the same for corvette, fords, crossfire and mercedes SLK320)
Wire from Pin 58 on the X1 connecter to the sense wire on the controller plug and thats it (besides programming the ECM, controller wires to power and ground plus to the fan)?
The reason I ask is diagrams show pin 58/green wire (which is what I have) as a low speed cooling fan relay control. plan is to wire the controller to the high speed side of the fan and using PWM to vary the fan speed.
Thank you.
11-03-2017, 12:59 PM
#3
Staging Lane
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LOL, last post says "anyone figure out the e38 yet"
ok, after reading the thread on lat-g, this is the closest to an answer I believe on pg 39.
Basically pick one wire, either the high speed (pin 17) or low speed relay (pin 58)?
The controller output is going to the high speed side only of the ford fan.
Originally Posted by mikentosh View Post
Wondering if anybody has troubleshooting advice for the PWM signal coming from an E38 ECU? I'm not seeing any PWM signal coming out from X1 pin 58.
I took my multimeter and put black probe to DkGrn wire coming from X1 pin 58, and red probe to battery positive terminal, and set to DC volts. Turning key on I can see the voltage go up to about 1.2V but regardless of toggling fans and duty cycle in HP Tuners I don't see any change. I would expect to see either ~5V or ~12V across here but do not. I didn't even bother to switch my multimeter over to duty cycle measurement, but assumed without the higher voltage its not working.
Any ideas on further troubleshooting? Pin 58 is a ground PWM signal correct?
posted by mikels
PWM fan output is frequency output - will not be able to 'measure' with voltmeter.
Cal also needs to be set to PWM output and frequency matched to PWM controller. All E40, E38, E67, E92 (and most all other GM ECM's from recent years) are capable of PWM fan control.
BTW - GM crate controller wiring joins fan1 and fan2 outputs to relay - need to separate to send fan1 only to PWM controller.
Dave
ok, after reading the thread on lat-g, this is the closest to an answer I believe on pg 39.
Basically pick one wire, either the high speed (pin 17) or low speed relay (pin 58)?
The controller output is going to the high speed side only of the ford fan.
Originally Posted by mikentosh View Post
Wondering if anybody has troubleshooting advice for the PWM signal coming from an E38 ECU? I'm not seeing any PWM signal coming out from X1 pin 58.
I took my multimeter and put black probe to DkGrn wire coming from X1 pin 58, and red probe to battery positive terminal, and set to DC volts. Turning key on I can see the voltage go up to about 1.2V but regardless of toggling fans and duty cycle in HP Tuners I don't see any change. I would expect to see either ~5V or ~12V across here but do not. I didn't even bother to switch my multimeter over to duty cycle measurement, but assumed without the higher voltage its not working.
Any ideas on further troubleshooting? Pin 58 is a ground PWM signal correct?
posted by mikels
PWM fan output is frequency output - will not be able to 'measure' with voltmeter.
Cal also needs to be set to PWM output and frequency matched to PWM controller. All E40, E38, E67, E92 (and most all other GM ECM's from recent years) are capable of PWM fan control.
BTW - GM crate controller wiring joins fan1 and fan2 outputs to relay - need to separate to send fan1 only to PWM controller.
Dave
11-03-2017, 06:01 PM
#4
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LOL, last post says "anyone figure out the e38 yet"
ok, after reading the thread on lat-g, this is the closest to an answer I believe on pg 39.
Basically pick one wire, either the high speed (pin 17) or low speed relay (pin 58)?
The controller output is going to the high speed side only of the ford fan.
Originally Posted by mikentosh View Post
Wondering if anybody has troubleshooting advice for the PWM signal coming from an E38 ECU? I'm not seeing any PWM signal coming out from X1 pin 58.
I took my multimeter and put black probe to DkGrn wire coming from X1 pin 58, and red probe to battery positive terminal, and set to DC volts. Turning key on I can see the voltage go up to about 1.2V but regardless of toggling fans and duty cycle in HP Tuners I don't see any change. I would expect to see either ~5V or ~12V across here but do not. I didn't even bother to switch my multimeter over to duty cycle measurement, but assumed without the higher voltage its not working.
Any ideas on further troubleshooting? Pin 58 is a ground PWM signal correct?
posted by mikels
PWM fan output is frequency output - will not be able to 'measure' with voltmeter.
Cal also needs to be set to PWM output and frequency matched to PWM controller. All E40, E38, E67, E92 (and most all other GM ECM's from recent years) are capable of PWM fan control.
BTW - GM crate controller wiring joins fan1 and fan2 outputs to relay - need to separate to send fan1 only to PWM controller.
Dave
ok, after reading the thread on lat-g, this is the closest to an answer I believe on pg 39.
Basically pick one wire, either the high speed (pin 17) or low speed relay (pin 58)?
The controller output is going to the high speed side only of the ford fan.
Originally Posted by mikentosh View Post
Wondering if anybody has troubleshooting advice for the PWM signal coming from an E38 ECU? I'm not seeing any PWM signal coming out from X1 pin 58.
I took my multimeter and put black probe to DkGrn wire coming from X1 pin 58, and red probe to battery positive terminal, and set to DC volts. Turning key on I can see the voltage go up to about 1.2V but regardless of toggling fans and duty cycle in HP Tuners I don't see any change. I would expect to see either ~5V or ~12V across here but do not. I didn't even bother to switch my multimeter over to duty cycle measurement, but assumed without the higher voltage its not working.
Any ideas on further troubleshooting? Pin 58 is a ground PWM signal correct?
posted by mikels
PWM fan output is frequency output - will not be able to 'measure' with voltmeter.
Cal also needs to be set to PWM output and frequency matched to PWM controller. All E40, E38, E67, E92 (and most all other GM ECM's from recent years) are capable of PWM fan control.
BTW - GM crate controller wiring joins fan1 and fan2 outputs to relay - need to separate to send fan1 only to PWM controller.
Dave
I thought earlier in that thread there was information specific to the e38 ECU.
Andrew