I have a 2010 F-350 6.4 diesel long bed with 59000 miles. I've only had it two weeks and yesterday the radiator fan came on and won't shut off. I'm getting the code P0528 on my banks IQ. I've searched this forum but can't find out what to do to fix it or get the fan clutch to work properly. I've already checked the plug that goes to the fan clutch and there is no bare wires or cracks that i can see. This is really annoying because the fan just roars the whole time you drive from takeoff to cruising speed. Thanks in advance for any advise.

 

fan speed sensor circuit.

maybe the sensor itself...

 

I checked with auto parts and they said there is no sensor. When i looked at it on the truck there's just a wire runs off the fan clutch then clips in the top of the fan shroud thats where the harness plugs into it?

 

I was looking into this more last night. I think it reads off of MAP Sensor and a couple other items.

Hard to pin this one down.

Do you have any warranty left? Or consider subsribing to the manual for a while so you can follow the diagnostics to find the issue.

Maybe you can check all the connecters for bent or dirty pins at the pcm.

 

The fan speed sensor is integral to the fan clutch unit. Unless there is some obstruction blocking the fan this isn't going to be servicable, it will be a full fan clutch replacement.


P0528 - Fan Speed Sensor Circuit No Signal
Description: The purpose of this diagnostic test is to compare the fan speed signal to the minimum and maximum calibrated values. If the fan speed is less than the minimum or greater than the maximum calibrated value, the DTC is set.
Possible Causes: Damaged FSS sensor
Damaged PCM
Obstruction stopping fan from moving

Diagnostic Aids: Visually inspect the cooling fan clutch for damage or obstruction.

Cooling Fan Connector
Pin Circuit
4 FSS (Fan Speed Sensor)
3 VBGND (Vehicle Buffered Ground)
5 VBPWR (Vehicle Buffered Power)
1 FCV (Fan Control Variable)
2 VPWR (Vehicle Power)



AH: Cooling Fan AH: Introduction

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AH1 PRELIMINARY DIAGNOSIS
Key in OFF position.
Record the freeze frame data.
Carry out the PCM self-test.
Are any DTCs present?
Yes No
For DTC P0494, P0495, P0528, P0529, GO to AH2 .

For DTC P0480, P0691, P0692, GO to AH3 .

For all others, REFER to Section 4, Diagnostic Trouble Code (DTC) Charts and Descriptions . GO to AH2 .

AH2 CHECK THE COOLING FAN FOR MECHANICAL BINDING
Note: A normally functioning cooling fan always has relative motion and slip between the fan and the water pump. When the fan is rotated normal resistance depends on the final cooling fan operational state before engine shutdown. Normal resistance includes smooth with intermittent resistance, significant resistance, and free wheeling.

Key in OFF position.
Manually rotate the cooling fan.
Does the fan clutch rotation feel rough or binding?
Yes No
INSTALL a new Cooling Fan. REFER to the Workshop Manual Section 303-03, Engine Cooling.

CLEAR the DTCs. REPEAT the self-test. GO to AH3 .



AH3 CHECK THE COOLING FAN OPERATION
Note: Inherent to viscous clutches is a delay in transitioning from a low to a high speed or from a high to a low speed. This delay is dependant upon engine speed, starting fan speed and clutch temperature. With the engine at operating temperature and at 2,500 RPM, the delay should be less than 30 seconds.

Note: The time required to change fan speed, once a command is issued by the PCM, varies depending on operating conditions such as temperature, engine speed and starting fan speed. The reaction time can be from seconds to several minutes depending on the test conditions.

Key ON, engine running.
Access the PCM and monitor the FANSS and RPM PIDs.
Engine at normal operating temperature.
Increase the engine speed to 2,500 RPM.
Access the PCM and control the FANDC PID.
Decrease the commanded cooling fan duty cycle to 0%.
Allow the fan speed to stabilize below 600 RPM.
Access the PCM and control the FANDC PID.
Increase the commanded cooling fan duty cycle to 100%.
Does the fan speed change and does the FANSS PID indicate an RPM change?
Yes No
If the FANSS PID stabilizes at less than 2,800 RPM with the engine speed at 2,500 RPM, INSTALL a new Cooling Fan. REFER to the Workshop Manual Section 303-03, Engine Cooling.

CLEAR the DTCs. REPEAT the self-test.

If the FANSS PID stabilizes at greater than 2,800 RPM with the engine speed at 2,500 RPM, the system is operating correctly at this time.

CLEAR the DTCs. REPEAT the self-test.

For cooling system concerns, REFER to the Workshop Manual Section 303-03, Engine Cooling for diagnosis and testing.

CLEAR the DTCs. REPEAT the self-test. If the fan speed did not change, GO to AH4 .

If the fan speed did change and the FANSS PID did not indicate an RPM change, GO to AH10 .

AH4 CHECK THE COOLING FAN RESISTANCE
Key in OFF position.
Cooling Fan connector disconnected.
Measure the resistance between:

( + ) Cooling Fan Connector, Component Side ( - ) Cooling Fan Connector, Component Side
VPWR - Pin 2 FCV - Pin 1


Is the resistance between 6 - 10 ohms?
Yes No
GO to AH5 . INSTALL a new Cooling Fan. REFER to the Workshop Manual Section 303-03, Engine Cooling.

CLEAR the DTCs. REPEAT the self-test.

AH5 CHECK THE FCV CIRCUIT FOR AN INTERNAL SHORT TO GROUND
Measure the resistance between:

( + ) Cooling Fan Connector, Component Side ( - )
FCV - Pin 1 Ground


Is the resistance greater than 10K ohms?
Yes No
GO to AH6 . INSTALL a new Cooling Fan. REFER to the Workshop Manual Section 303-03, Engine Cooling.

CLEAR the DTCs. REPEAT the self-test.

AH6 CHECK THE VPWR CIRCUIT FOR VOLTAGE
Key ON, engine OFF.
Measure the voltage between:

( + ) Cooling Fan Connector, Harness Side ( - )
VPWR - Pin 2 Ground


Is the voltage greater than 10.5 V?
Yes No
GO to AH7 . REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test.

AH7 CHECK THE FCV CIRCUIT FOR AN OPEN CIRCUIT IN THE HARNESS
Key in OFF position.
PCM-E connector disconnected.
Measure the resistance between:

( + ) Cooling Fan Connector, Harness Side ( - ) PCM-E Connector, Harness Side
FCV - Pin 1 FCV - Pin 95,96


Is the resistance less than 5 ohms?
Yes No
GO to AH8 . REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test.

AH8 CHECK THE FCV CIRCUIT FOR A SHORT TO GROUND IN HARNESS
Measure the resistance between:

( + ) Cooling Fan Connector, Harness Side ( - )
FCV - Pin 1 Ground


Is the resistance greater than 10K ohms?
Yes No
GO to AH9 . REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test.

AH9 CHECK THE FCV CIRCUIT FOR A SHORT TO VOLTAGE IN THE HARNESS
Key ON, engine OFF.
Measure the voltage between:

( + ) Cooling Fan Connector, Harness Side ( - )
FCV - Pin 1 Ground


Is any voltage present?
Yes No
REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test. GO to AH19 .

AH10 CHECK THE FAN SPEED SENSOR FOR VOLTAGE
Key ON, engine OFF.
Cooling Fan connector disconnected.
Measure the voltage between:

( + ) Cooling Fan Connector, Harness Side ( - ) Cooling Fan Connector, Harness Side
VBPWR - Pin 5 VBGND - Pin 3


Is the voltage greater than 10.5 V?
Yes No
GO to AH15 . GO to AH11 .

AH11 CHECK THE VBPWR CIRCUIT FOR VOLTAGE
Measure the voltage between:

( + ) Cooling Fan Connector, Harness Side ( - )
VBPWR - Pin 5 Ground


Is the voltage greater than 10.5 V?
Yes No
GO to AH14 . GO to AH12 .

AH12 CHECK THE VBPWR CIRCUIT FOR AN OPEN
Key in OFF position.
PCM-E connector disconnected.
Measure the resistance between:

( + ) Cooling Fan Connector, Harness Side ( - ) PCM-E Connector, Harness Side
VBPWR - Pin 5 VBPWR - Pin 91


Is the resistance less than 5 ohms?
Yes No
GO to AH13 . REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test.

AH13 CHECK THE VBPWR CIRCUIT FOR A SHORT TO GROUND
Measure the resistance between:

( + ) Cooling Fan Connector, Harness Side ( - )
VBPWR - Pin 5 Ground


Is the resistance greater than 10K ohms?
Yes No
GO to AH19 . REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test.

AH14 CHECK THE VEHICLE BUFFER GROUND VBGND CIRCUIT FOR AN OPEN
Key in OFF position.
PCM-E connector disconnected.
Measure the resistance between:

( + ) Cooling Fan Connector, Harness Side ( - ) PCM-E Connector, Harness Side
VBGND - Pin 3 VBGND - Pin 40


Is the resistance less than 5 ohms?
Yes No
GO to AH19 . REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test.

AH15 CHECK THE FAN SPEED SENSOR SIGNAL CIRCUIT FOR AN OPEN
Key in OFF position.
PCM-E connector disconnected.
Measure the resistance between:

( + ) Cooling Fan Connector, Harness Side ( - ) PCM-E Connector, Harness Side
FSS - Pin 4 FSS - Pin 90


Is the resistance less than 5 ohms?
Yes No
GO to AH16 . REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test.

AH16 CHECK THE SIGNAL CIRCUIT FOR A SHORT TO GROUND
Measure the resistance between:

( + ) Cooling Fan Connector, Harness Side ( - )
FSS - Pin 4 Ground


Is the resistance greater than 10K ohms?
Yes No
GO to AH17 . REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test.

AH17 CHECK THE SIGNAL CIRCUIT FOR A SHORT TO VOLTAGE
Key ON, engine OFF.
Measure the voltage between:

( + ) Cooling Fan Connector, Harness Side ( - )
FSS - Pin 4 Ground


Is any voltage present?
Yes No
REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test. GO to AH18 .

AH18 CHECK THE SIGNAL CIRCUIT FOR VOLTAGE
Key in OFF position.
PCM-E connector connected.
Key ON, engine OFF.
Measure the voltage between:

( + ) Cooling Fan Connector, Harness Side ( - )
FSS - Pin 4 Ground


Is the voltage greater than 10 V?
Yes No
INSTALL a new Cooling Fan. REFER to the Workshop Manual Section 303-03, Engine Cooling.

CLEAR the DTCs. REPEAT the self-test. GO to AH19 .

AH19 CHECK FOR CORRECT PCM OPERATION
Disconnect all the PCM connectors.
Visually inspect for:
pushed out pins
corrosion
Connect all the PCM connectors and make sure they seat correctly.
Carry out the PCM self-test and verify the concern is still present.
Is the concern still present?
Yes No
INSTALL a new PCM. REFER to Section 2, Flash Electrically Erasable Programmable Read Only Memory (EEPROM) . The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.

 

the fanss sensor is part of the fan clutch, there is a tsb that states to replace the clutch

 

Thanks for all the input guys. I pulled the plug for the pcm and inspected it really close and discovered one of the pins was pushed back. I managed to push the pin back out and it seemed to click back into place. Anyway I put the plug back on and my problem went away. So thanks again.