Test Procedure

WARNING: This page does not describe the selected car, but rather 9 other vehicles, including the 2022 Ford F-550 Super Duty, 2022 Ford F-450 Super Duty, 2022 Ford F-350 Super Duty, 2022 Ford F-250 Super Duty, and 2021 Ford F-550 Super Duty. However, it is still accessible from the selected car via links, so may be relevant.

KN1 CHECK FOR DIAGNOSTIC TROUBLE CODES (DTCS)

Is DTC P0480 present?

Yes	No
GO to KN4.	For symptoms without DTCs, GO to KN2. For all others, RETURN to SYMPTOM CHARTS for further direction.

KN2 VERIFY A/C STATUS

Verify the A/C system is OFF.
Ignition ON, engine running.
Access the PCM and monitor the AC_REQ (MODE) PID.

Is A/C being requested?

Yes	No
REFER to the appropriate Climate Control System article, to diagnose the A/C system.	For electric cooling fan(s) always on, GO to KN3. For all others, GO to KN4.

KN3 CHECK THE AIR CONDITIONING PRESSURE TRANSDUCER SENSOR

Ignition OFF.
ACP Sensor connector disconnected.
Ignition ON, engine running.

Does the cooling fan turn off?

Yes	No
REFER to the appropriate Climate Control System article, to diagnose the Air Conditioning Pressure (ACP) Sensor.	GO to KN4.

KN4 COMMAND THE COOLING FAN ON TO CHECK OPERATION

NOTE: Some vehicles have more than one cooling fan. Make sure both cooling fans operate correctly.

Ignition ON, engine OFF.
Access the PCM and control the FAN_DSD (PER) PID.
Command the fan to full ON.

Does the cooling fan operate when commanded ON?

Yes	No
The concern is elsewhere. RETURN to NO DIAGNOSTIC TROUBLE CODES (DTCS) PRESENT SYMPTOM CHART INDEX for further direction.	GO to KN5.

KN5 CHECK THE VOLTAGE TO THE COOLING FAN

Ignition OFF.
CF Module connector disconnected.
Ignition ON, engine OFF.
Measure the voltage between:

(+) CF Module Connector, Harness Side	(-)
FANPWR - Pin 1	Ground

Is the voltage greater than 10.5 V?

Yes	No
GO to KN7.	GO to KN6.

KN6 CHECK THE RELAY GROUND CIRCUIT

Ignition OFF.
BJB-A connector disconnected.
Measure the resistance between:

(+) BJB-A Connector, Harness Side	(-)
GND - Pin 1	Ground

Is the resistance less than 5 ohms?

Yes	No
GO to KN7.	REPAIR the open circuit. Clear the PCM DTCs. REPEAT the self-test.

KN7 CHECK FOR AN OPEN

Ignition OFF.
BJB-A connector disconnected.

Measure the resistance between:

(+) CF Module Connector, Harness Side	(-)
GND - Pin 2	Ground

Measure the resistance between:

(+) CF Module Connector, Harness Side	(-) PCM-B Connector, Harness Side
FCV - Pin 4	FCV - Pin 80

Measure the resistance between:

(+) CF Module Connector, Harness Side	(-) BJB-A Connector, Harness Side
FANPWR - Pin 1	FANPWR - Pin 20

Are the resistances less than 5 ohms?

Yes	No
GO to KN8.	REPAIR the open circuit. Clear the PCM DTCs. REPEAT the self-test.

KN8 CHECK THE FCV FOR A SHORT TO GROUND

Measure the resistance between:

(+) CF Module Connector, Harness Side	(-)
FCV - Pin 4	Ground

Are the resistances greater than 10k ohms?

Yes	No
GO to KN9.	REPAIR the short circuit. Clear the PCM DTCs. REPEAT the self-test.

KN9 CHECK THE FCV FOR A SHORT TO VOLTAGE

Ignition ON, engine OFF.
Measure the voltage between:

(+) CF Module Connector, Harness Side	(-)
FCV - Pin 4	Ground

Is any voltage present?

Yes	No
REPAIR the short circuit. Clear the PCM DTCs. REPEAT the self-test.	GO to KN10.

KN10 CHECK THE FCV FOR INTERMITTENT CONCERNS

Ignition OFF.
BJB-A connector disconnected.
CF Module connector disconnected.
Visually inspect all connectors for:
- pushed out pins
- corrosion
BJB-A connector connected.
CF Module connector connected.
Ignition RUN Engine RUN.
Access the PCM and control the FAN_DSD (PER) PID.
Command the fan to full ON.
While observing the fan, wiggle, shake, and bend small sections of the wiring harness while working from the cooling fan to the PCM.

Is a concern present?

Yes	No
REPAIR as necessary. If a wiring concern is not present, INSTALL a new cooling fan. REFER to the appropriate Engine Cooling article. Clear the PCM DTCs. REPEAT the self-test.	The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.