It has happened to me! (Dreaded Fan Sensor - Crumbling Hose!)

[HeatXfer]

Ok so how do you propose we resolve the shock absorbing effect of the hose and integrate a break away function? Inquiring minds want to know..

After observing a start from cold and the cycling of the fan, I'm convinced the shock from torque is minimal and was probably a secondary design concern. A fan clutch failure wouldn't affect the stationary electrical component, but a hose failure certainly would allow the fan clutch wiring to fall into the spinning hub. That fan never stops spinning, so that weak connection on the motor side is subjected to some level of constant vibration.

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[Muffin1]

Curious to know from members with the global Ranger across the pond if their setup is the same, or did Ford just bless us with this engineering debacle?

And i'm just guessing here but i 'think more time has been spent in these threads trying to figure out why and a better repair/fix than the engineers spent designing this rush job of an idea.

 

[TJC]

I looked and didn't find similar issues with the F150 designs. One wonders why they didn't stick with a proven design. I mean, it's in the parts bin!

 

[airline tech]

Cooling Fan Connector:
Service Part Number: HU2Z-14S411-LA
Pigtail Kit Part Number WPT-1504

Pin 1: Power Feed shared with other circuits; this is what generates so many other faults with it.
Creates short circuit and takes out the whole circuit - which puts truck into LIMP Mode
Pin 2: PCM Control for Fan Speed (PWM-Pulse Width Modulated)
Pin 3: Crankshaft Position Sensor Circuit (Actual Engine RPM Data) -Crank
Pin 4: Camshaft Position Sensor Circuit (Actual Engine RPM Data) - Cam
Pin 5: Fan Speed Sense (Reports Back to the PCM) actual Fan Speed

 

[HeatXfer]

Why would there be cam position and crank speed sensor wires running to the fan clutch module? I'm assuming there's logic in the fan module that uses data from thoses sensors, rather than just coolant temp or A/C use? Anticipation of engine load?

 

[TJC]

They aren't, but they share the same fusible power source. When the fan clutch wiring fails and the fuse blows, all the others systems that Airline Tech mentioned lose power too.

 

[HeatXfer]

They aren't, but they share the same fusible power source. When the fan clutch wiring fails and the fuse blows, all the others systems that Airline Tech mentioned lose power too.

So why have those particular wires run to the fan clutch? Also the wiring diagram is confusing because the cooling fan is labeled as a "motor" and the wire labels don't match. Is this a printing error? My book is for a 2019.

There's no 'CKP' or 'VRSRTN' in the wiring diagram and no 'VREF' or 'SIGRTN' at the connector. Knowing the purpose of those wires at the fan module would make things a lot clearer.

 

[airline tech]

Why would there be cam position and crank speed sensor wires running to the fan clutch module? I'm assuming there's logic in the fan module that uses data from thoses sensors, rather than just coolant temp or A/C use? Anticipation of engine load?

Pin 1 = 12 Volt Power

Pin 2 = PWM - Pulse Width Modulated, Control of the Fan Clutch - The control side is factoring in Engine Temp, AC Running, Engine RPM Data and Fan Speed, to control the viscous fluid movement in and out of the reservoir - To Control Fan Speed
With using the 5-Volt Ref as feedback

Part of the VREF circuit:
Pin 3 = VREF Input from Crank (5-Volt Reference)
Pin 4 = VREF Signal Return to Camshaft,
Its monitoring Engine RPM data
Pin 5 = Actual Fan Speed (FSS-Fan Speed Sense) as picked up by the Hall Effect Sensor
This is the Nubs on the backside of the fan clutch (rotating) the module (sensor) reads this as fan speed - and provides feedback to the PCM, while comparing Crank & Cam RPM data it knows the difference in speeds.

Pin 3 - PCM ---Crank----Fan - VREF (5-Volts) Input
Pin 4 - Fan ---Cam -----PCM -VREF (Signal Return)
Pin 5 - (= the speed signal of all) Rotational Speed - To the PCM

 

[Joejk3d]

Hmm this is all pretty wild and pretty simple. Clearly they need some flex to avoid the shock fatigue of the fan engaging, but in the words of 90's informercials - there has to be a better way!

I am curious if some careful 3D design with a high tensile/durable and high temp TPU would help augment this setup. I work with some crazy impressive TPU blends (Easton makes them) for some of my other 3D printing projects and may have to take a swing at something with this...

Needs to be fatigue resistant, temp stable, rigid enough to avoid the fan from rotating, but soft enough to avoid passing the shock of the clutch engaging to the mount or damaging the fan clutch itself... complicated situation where adding steel braiding may caused more issues than it solves!

 

[airline tech]

So why have those particular wires run to the fan clutch? Also the wiring diagram is confusing because the cooling fan is labeled as a "motor" and the wire labels don't match. Is this a printing error? My book is for a 2019.

There's no 'CKP' or 'VRSRTN' in the wiring diagram and no 'VREF' or 'SIGRTN' at the connector. Knowing the purpose of those wires at the fan module would make things a lot clearer.

Ironic - we are posting the same thing at the same time.

The drawing is for (Visual Reference) to see that Pin 5 = The Signal Circuit (potentiometer)

Pin 1 - Power (shared power - via the splices (black dots)
Pin 2 - Is PWM (Pulsed Ground) from the PCM (speed control)

 

[airline tech]

Here is a better diagram - note this one adds another sensor on the circuit.
Exhaust Press Sensor

 

[HeatXfer]

Ahh, I see now, thank you for that. Each splice (in these diagrams) is either sharing voltage for sensor operation or it's part of the CAN bus returning info back to the PCM? I'm familiar with PWM, 4-20mA, 5-10vdc control signals and PLC operation but I wasn't taking into account that the CAN bus uses the same wire for multiple signals. I do find the labeling a bit confusing though.

 

[airline tech]

Finally found what I was looking for - Complete System Diagram (less unnecessary info)

So, The VREF Circuit (5-Volt) Power is feeding multiple engine sensors.
Shared Circuit - with a branch (splice) out to Circuit LE135 (Crank- Fan - Ex Press)
However, the Fan Control (Signal Return) is only looking at signal return voltage.
for Circuit RE249 - Cam 1-Cam 2-Fan

VREF - Circuits can be a challenge sometimes as it integrates other circuits.

 

[HeatXfer]

Finally found what I was looking for - Complete System Diagram (less unnecessary info)

So, The VREF Circuit (5-Volt) Power is feeding multiple engine sensors.
Shared Circuit - with a branch (splice) out to Circuit LE135 (Crank- Fan - Ex Press)
However, the Fan Control (Signal Return) is only looking at signal return voltage.
for Circuit RE249 - Cam 1-Cam 2-Fan

VREF - Circuits can be a challenge sometimes as it integrates other circuits.

Got it! It's taken me a minute to get up to speed so the guidance is appreciated! I've worked a lot installing and programing Siemens controls and PLC controllers. I'm only vaguely familiar with CAN bus - All the functions of my KTM, like BMW, are CAN bus controlled. Thanks again.

 

[TJC]

Here is a better diagram - note this one adds another sensor on the circuit.
Exhaust Press Sensor

The more complicated the plumbing, the easier it is to stop it up!

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