Test Procedure

WARNING: This page does not describe the selected car, but rather 9 other vehicles, including the 2004 Ford RV Cutaway, 2004 Ford Pickup, 2004 Ford F550 Super Duty, 2004 Ford F450 Super Duty, and 2004 Ford Excursion. However, it is still accessible from the selected car via links, so may be relevant.

AK1 PRELIMINARY DIAGNOSIS FOR DTC P0046

NOTE: Refer to the PCM and component connector, Figure and Figure at the beginning of this pinpoint test.

Perform the visual inspection.
Connect the scan tool.
Retrieve and record all DTCs.
Record freeze frame data.
Clear all DTCs.
Perform the On-Demand Self Test.

IS DTC P0046 PRESENT?

Yes	No
Go to AK2.	UNABLE to duplicate condition. CHECK for loose connections, damaged or corroded terminals or pins. WIGGLE harness attempting to recreate fault. REPAIR as necessary. REFER to SYMPTOM CHARTS - 6.0L DIESEL if a driveability concern exists.

AK2 DIAGNOSTIC TROUBLE CODE (DTC) P0046

Possible causes:
- control circuit open
- control circuit shorted to voltage
- control circuit shorted to ground
- VGT actuator
- PCM.
Key off.
Disconnect the VGT actuator electrical connector.
Key on.
Measure the voltage between the VGT electrical connector pin 1 and ground.

IS THE VOLTAGE GREATER THAN 11.0 VOLTS?

Yes	No
Go to AK3.	REPAIR open in circuit. RESTORE the vehicle. CLEAR DTCs and RETEST the system.

AK3 CHECK VGT ACTUATOR

Key off.
Enter output state control.
Install a test light between the VGT electrical connector pins 1 and 2, harness side.
Key on.
Access VGT PIDS.
Command VGT to below 10% duty cycle.
Command the VGT to 85% duty cycle.

DOES THE TEST LIGHT GO OUT AS VGT DUTY CYCLE IS DRIVEN LOW AND LIGHTS AS THE DUTY CYCLE IS DRIVEN HIGH?

Yes	No
Go to AK7.	Go to AK4.

AK4 CHECK VGT CONTROL CIRCUIT FOR A SHORT TO VOLTAGE

Key off.
Remove the test light.
Disconnect the PCM engine harness electrical connector.
Key on.
Measure the voltage between the VGT actuator harness connector pin 2 and ground.

IS THE VOLTAGE LESS THAN 0.2 VOLTS?

Yes	No
Go to AK5.	REPAIR short in control circuit. RESTORE the vehicle. CLEAR DTCs and RETEST the system.

AK5 CHECK VGT CONTROL CIRCUIT FOR A SHORT TO GROUND

Key off.
Measure the resistance between VGT actuator connector pin 2 and ground.

IS THE RESISTANCE GREATER THAN 10,000 OHMS?

Yes	No
Go to AK6.	REPAIR short in control circuit. RESTORE the vehicle. CLEAR DTCs and RETEST the system.

AK6 CHECK VGT CONTROL CIRCUIT FOR AN OPEN

Measure the resistance between the VGT actuator connector pin 2 and PCM connector pin 10.

IS THE RESISTANCE LESS THAN 5 OHMS?

Yes	No
REPLACE the PCM.	REPAIR open in control circuit. RESTORE the vehicle. CLEAR DTCs and RETEST the system.

AK7 CLEAN THE VGT ACTUATOR VALVE AND RETEST

CAUTION: The VGT actuator valve is sensitive to contamination. All work areas must be clean before starting this procedure. Do not allow contamination to enter the valve ports, cam follower, or turbocharger housing. Handle the VGT actuator by the solenoid body only. Do not attempt to wipe oil off the valve. Do not let the valve come in contact with materials that could contaminate the valve mechanism.

CAUTION: Use only the Carburetor Tune-Up Cleaner PM-2 to spray the actuator valve. Brake cleaner or other solvents may damage the actuator valve.

Remove the VGT actuator from the turbocharger assembly.
NOTE: Do not spray the zinc coated larger diameter housing, or electrical connector.
Spray the valve with Carburetor Tune-Up Cleaner PM-2 while pressing the cam follower (tip of the actuator).
Install the VGT actuator and connect the VGT connector.
Key ON, engine running.
Access the output state control.
Access the VGT PID.
Increase the commanded engine speed to 1,250 RPM using output state control. The calibration may limit the actual RPM between 1,150 and 1,200 RPM.
Increase the VGT duty cycle to greater than 70%.
Decrease the VGT duty cycle to 0%.

DOES THE TURBOCHARGER PITCH CHANGE WHEN THE VGT DUTY CYCLE IS INCREASED AND DECREASED?

Yes	No
The system is operating correctly at this time. The concern may have been caused by a contaminated VGT actuator valve. CHANGE the oil and oil filter assembly.	INSTALL a new VGT actuator. CLEAR the DTCs. REPEAT the self-test.