Yes, Relay is power, PCM provides pulse width modulation for a quit fan operation. Power go to the fans and ground is controlled by electronics in the module. It is common practice to use N-Channel MOSFET that when switched on, provide a path to ground. The MOSFET can be switched on-off very rapidly. The problem is they produce a great deal of heat, so a heat transfer grease is used to bolt these directly to the heat sink on the back. Unfortunately, due to heat or vibration, the board can fracture, solder joints melt and create open intermittent conditions that allow the mosfet to not drain at the gate turn on voltage thru a resistor. So, let’s take a very thin, not so robust printed circuit board, then we will place it on the hot side of the radiator with a heat sink that absorbs heat and perhaps to small for the amperage/heat generated by the mosfets (1 for each fan) and see how long it will last! (Answer-Out of Warranty) By the Beck-Arnely brand from Rock Auto. It is the same as Ford…I mean Mazda. Or better for less! retired auto master tech
Literally just came from advanced auto where they told me this module doesnt exist, glad theres a video imma go back and shove this in their faces and make them order my damn part 🤣
Mazda does ford better than ford. Fords only good subcompacts were designed by mazda, the ranger truck, ford escort. Yea, escort was bad but then think about the cavilier or neon, yea, none are still driving. Its not uncommon to see escorts and rangers, or even tge mazda trucks.
Anyone measure the resistance of the fan motor? Mine is at 0.4ohms. Thinking my fan is fried, with 12V supplied to the motor this gives a current of 30Amps. Gates manufacturing (where I bought the FCM) says to replace fan motor if it is drawing over 10Amps of current.
I have the same prob, though my ac makes a whining sound and when I just have the fan on (AC) off AC still comes on. When heater is on ,still hear ac wine, but blows hot like it should… Fan module???
Dude we need a mechanic like you here! Thanks for the vid! I think I my girlfriends car has this problem. Do you have a video on how to replace the CFM? Tks!
Great video! My car is having this current issue but it is draining the battery as a result. Do you think that it is necessary to replace the entire full fan assembly or just replacing the radiator fan control module will suffice?
This is really a partial diagnosis, if the PCM is bad then you should also check the Amps being pulled by the cooling fans themselves with an ammeter, as they get older and start to go bad they get hot, pull too many amps and blow the PCM. If you don't check the Amps (for a this vehicle it should be 6.6 Amps from each Fan) you'll end up blowing another PCM and needing to replace both fan motors and the PCM again.
I have an 04 V6 Mazda 6 like this one but I've never once heard my fans turn on, no matter what driving conditions. Would it be safe to assume it's the FCM?
I really do believe that these engineers come up with some design changes just to try and justify their position. it is something new and or different so it must be better! or because they came up with it, that means it is better. we all have our delusions I suppose. I would have to pick Toyota as having the best electrical/electronic design and component quality. not to say they do not have their issues
Thanks for posting, you are not only making us DIY's more capable, you are making your customers better car owner's by showing them the high level of skill and specialized equipment required to diagnose and repair their automobiles.
Had a Mazda 6 4 cyl with similar issue, fans would come on with no key in car and flatten battery. Was the fan module which comes with the fans. in Australia we can buy these aftermarket much cheaper then genuine. Great vids, keep em coming.
Fan control module is there for a reason: other conditions may trigger the fan to run even though the ECU is silent. However it could be the bad module too. The control module logic will help here.
What about when it cycles on and off even after changing module ?
So my car is doing the same thing and over heating I just wanna know where that thermostat sensor is
See mine does that after you turn it off and before i actually start the engine up where windows and radio are working
Yes, Relay is power, PCM provides pulse width modulation for a quit fan operation. Power go to the fans and ground is controlled by electronics in the module. It is common practice to use N-Channel MOSFET that when switched on, provide a path to ground. The MOSFET can be switched on-off very rapidly. The problem is they produce a great deal of heat, so a heat transfer grease is used to bolt these directly to the heat sink on the back. Unfortunately, due to heat or vibration, the board can fracture, solder joints melt and create open intermittent conditions that allow the mosfet to not drain at the gate turn on voltage thru a resistor.
So, let’s take a very thin, not so robust printed circuit board, then we will place it on the hot side of the radiator with a heat sink that absorbs heat and perhaps to small for the amperage/heat generated by the mosfets (1 for each fan) and see how long it will last! (Answer-Out of Warranty)
By the Beck-Arnely brand from Rock Auto. It is the same as Ford…I mean Mazda. Or better for less!
retired auto master tech
Nice video man. Your diagnostic procedure was perfect
Literally just came from advanced auto where they told me this module doesnt exist, glad theres a video imma go back and shove this in their faces and make them order my damn part 🤣
Thanks for taking the time to show this.
check the god damn fans as well you twat. they are probably drawing to many amps and that's what caused the module to go bad.
christ almighty. why does it sound like a top fuel dragster?!
Great job
Mazda does ford better than ford. Fords only good subcompacts were designed by mazda, the ranger truck, ford escort. Yea, escort was bad but then think about the cavilier or neon, yea, none are still driving. Its not uncommon to see escorts and rangers, or even tge mazda trucks.
NCA No color Assigned.
Anyone measure the resistance of the fan motor? Mine is at 0.4ohms. Thinking my fan is fried, with 12V supplied to the motor this gives a current of 30Amps. Gates manufacturing (where I bought the FCM) says to replace fan motor if it is drawing over 10Amps of current.
They had a recall on that module. Changed them daily when I worked at the Mazda dealership.
That's a hurricane fan!
I have a mazda that the fan is running full speed with the ignition off. Could this module be at fault?
My girlfriend has a 2006 Mazda6 with the 3.0 and hers behaves in the exact same way. So glad somebody posted a video about it!
I have a 2006 Mazda 6s with 162,xxx miles and it has the same problem. Thank you for the video. It was very helpful.
I have the same prob, though my ac makes a whining sound and when I just have the fan on (AC) off AC still comes on. When heater is on ,still hear ac wine, but blows hot like it should… Fan module???
Dude we need a mechanic like you here!
Thanks for the vid! I think I my girlfriends car has this problem.
Do you have a video on how to replace the CFM?
Tks!
Great video! My car is having this current issue but it is draining the battery as a result. Do you think that it is necessary to replace the entire full fan assembly or just replacing the radiator fan control module will suffice?
my 2005 Mazda 6 3.0 did the exact same thing. thanks for the helpful video!
Ahhh the video that introduced me to this channel.
This is really a partial diagnosis, if the PCM is bad then you should also check the Amps being pulled by the cooling fans themselves with an ammeter, as they get older and start to go bad they get hot, pull too many amps and blow the PCM. If you don't check the Amps (for a this vehicle it should be 6.6 Amps from each Fan) you'll end up blowing another PCM and needing to replace both fan motors and the PCM again.
Thanks for helping me diagnose, my 05 mazda had the same issue. Keep up the great work on the videos!
I have an 04 V6 Mazda 6 like this one but I've never once heard my fans turn on, no matter what driving conditions. Would it be safe to assume it's the FCM?
Hmm, as ScannerDanner says, is the ground good at the fan module?
we appreciate the time you take to inform us how to fix our own cars or help fix other peoples cars , thank you and keep em comin.
also my car has 2 modules
I have an 07 mazda cx7 and the fans come on only for a/c but low speed I replaced the module but still no cooling fans anything else I could try tnx
Concidering the situation I think it went well! Thanks!
great, thanks…
i think my moduler was bad and burned my fans up. good lesson here.
my friend i found this item but it says this…….what is this means…..how do i know if is compatible with my car…hope you can help me thanks
Replaces
OE # 1355A124, AJ511515YA, AJY215SC0, AJY215SCO, L3361515YA
OE # AJ511515YA
I really do believe that these engineers come up with some design changes just to try and justify their position. it is something new and or different so it must be better! or because they came up with it, that means it is better. we all have our delusions I suppose. I would have to pick Toyota as having the best electrical/electronic design and component quality. not to say they do not have their issues
Thanks for posting, you are not only making us DIY's more capable, you are making your customers better car owner's by showing them the high level of skill and specialized equipment required to diagnose and repair their automobiles.
if i support the channel will you stop that damn ringbell?i know you have a lot of clients but jeezz XD lol
If I support the channel will you use the donation for a new hat?
Had a Mazda 6 4 cyl with similar issue, fans would come on with no key in car and flatten battery. Was the fan module which comes with the fans. in Australia we can buy these aftermarket much cheaper then genuine.
Great vids, keep em coming.
what settings did you used for the old vantage?
please use the scope more often 🙂
i learned something today 🙂
That pcm is like big brother,controls everything,
cooling fan comes on and yank!.. then vantage gets sucked in cooling fan,,
Fan control module is there for a reason: other conditions may trigger the fan to run even though the ECU is silent. However it could be the bad module too. The control module logic will help here.
We have a 3.2 v6 2004 a3 and the cooling fan stays on that for good 30 seconds normal so min told
Quick, accurate diagnosis. Good work Eric!
When the PCM is commanding the Cooling Fans to come on, there is a "Wave" pattern on the Vantage. Is this Voltage or Current?