2005-2006 Mustang 2004-2005 F-150 2005-2006 Expedition, F-Super Duty 2006 Explorer 2007 Explorer Sport Trac
This article supersedes TSB 06-2-9 to add a production fix date for Expedition and Navagator and service parts updated.
Some 2005-2006 F-Super Duty and Expedition/Navigator vehicles built prior to 12/14/2005 and 2004-2005 F-150 vehicles, equipped with 5.4L 3V engine, and 2005-2006 Mustang GT vehicles, equipped with 4.6L 3V engine, may exhibit a diagnostic trouble code (DTC) P0340 and/or P0344; or 2006 Explorer 4dr/Mountaineer and 2007 Explorer Sport Trac vehicles equipped with a 4.6L 3V engine may exhibit a DTC P0345 and/or P0349. This may be due to a malfunctioning diode or open phase connection in the generator.
Perform a generator frequency test to diagnose cause of concern. Do not replace the generator unless a frequency test indicates a fault. This TSB provides step-by-step directions for performing a generator frequency test using the WDS oscilloscope function.
USING THE OSCILLOSCOPE TO MEASURE PEAK-TO-PEAK VOLTAGE IS NOT A GOOD INDICATOR OF A FAULTY GENERATOR.
ENSURE THERE IS NO BATTERY CHARGER CONNECTED TO THE VEHICLE.
Ensure the connections to the battery terminals, engine grounds, and generator B+ are clean and secure.
Attach WDS battery cable clamps to battery/battery cables.
Turn on WDS.
Select the Toolbox Icon, (upper left of WDS screen).
Select Oscilloscope and then click OK.
Select Channel 1, Auto, Generator Ripple.
Select Calculations, Channel 1, Frequency.
Select Calculations again.
Push the RUN/STOP button. A waveform should display on the screen.
Start the vehicle and leave at idle (engine speed less than 800 RPM).
Turn on vehicle loads (high beams, blower set on high, heated seats, defroster, etc).
Examine the frequency reading on WDS.
WDS CAN CALCULATE THE FREQUENCY AUTOMATICALLY. THE CALCULATED FREQUENCY IS LOCATED ON THE LOWER LEFT AREA OF THE OSCILLOSCOPE SCREEN. SOMETIMES THE FREQUENCY CANNOT BE CALCULATED BECAUSE THE WDS CANNOT RECOGNIZE AND MEASURE PEAK VALUES. IF THE WDS CANNOT CALCULATE THE FREQUENCY, IT WILL DISPLAY "INVALID" WHERE THE FREQUENCY READING SHOULD BE. THIS IS NORMAL IF THE RIPPLE VOLTAGE IS TOO LOW.
For a proper visible wave pattern, adjust the voltage scale and time scale until a good wave pattern is visible. Typically, a setting of 1mS/div and 100mV/div is a good starting point and can be adjusted as necessary.
Run vehicle until signal is steady. Then select the "RUN/STOP" button to freeze the waveform.
Determine if the generator is faulty based on frequency measurement:
FREQUENCY IS DEPENDENT ON ENGINE RPM. PERFORM ALL TESTS AT IDLE OR FREQUENCY READINGS WILL BE INACCURATE.
Compare the WDS saved waveform to the sample waveforms in Figure 1. If measured ripple frequency is lower than 500 Hz, then generator is faulty and should be replaced. If generator is not faulty proceed to Step 16.
If frequency calculation cannot be made by WDS, it can be calculated manually. See MANUALLY CALCULATE FREQUENCY. If calculated ripple frequency is lower than 500 Hz, then generator is faulty and should be replaced. If generator is not faulty proceed to Step 16.
MANUALLY CALCULATE FREQUENCY
Count the number of complete voltage dips over a given range of divisions on the scope trace
Divide the number of voltage dips by the number of divisions to get the average voltage dips/division
Divide the value in Step 2 by the time scale (e.g. 1mS/div = .001 sec/division) to get frequency
THIS METHOD OF CALCULATING FREQUENCY IS SLIGHTLY DIFFERENT THAN THE METHOD USED BY WDS, SO THE FREQUENCY MEASUREMENT VS. CALCULATED MAY BE SLIGHTLY DIFFERENT.
If the frequency test does not indicate a fault with the generator, proceed with normal Powertrain Controls/Emissions Diagnosis (PC/ED) diagnostics for the DTC. For F-Super Duty vehicles only, if the DTCs are still present after diagnostics, reprogram the powertrain control module (PCM) to the latest calibration using WDS release B38.11 and higher or B39.2 and higher. Calibration files may also be obtained at www.motorcraft.com. This new calibration is not included in the B39 CD. (DO NOT REPROGRAM EXPEDITION/NAVIGATOR, F-150, MUSTANG, EXPLORER, MOUNTAINEER OR EXPLORER SPORT TRAC).
Generator - Standard Duty - Expedition/Navigator
Generator - Heavy Duty - Expedition/Navigator
Generator - F-150
Generator - F-Super Duty
Generator - Mustang
Generator - Explorer/Mountaineer
Generator - Explorer Sport Trac
Eligible Under Provisions Of New Vehicle Limited Warranty Coverage
2005-2006 Expedition/Navigator 5.4L 3V: Diagnose Generator Using WDS, If Generator Is Found Defective Replace Generator (Do Not Use With 10346A, 10200A)
2005-2006 Super Duty, 2004-2005 F150 5.4L 3V: Diagnose Generator Using WDS, If Generator Is Found Defective Replace Generator (Do Not Use With 10346A, 10200A)
2005-2006 Super Duty, 5.4L 3V: Diagnose Generator Using WDS, If Generator Is Found To Be Functioning Properly Reprogram The Powertrain Control Module (Do Not Use With 10346A, 10200A, 12650D, 12650D84)
2005-2006 Mustang 4.6L 3V: Diagnose Generator Using WDS, If Generator Is Found Defective Replace Generator (Do Not Use With 10346A, 10200A, 9926A, 12650D, 12650D84)
2006 Explorer/Mountaineer/2007 Explorer Sport Trac 4.6L 3V: Diagnose Generator Using WDS, If Generator Is Found Defective Replace Generator. (Do Not Use With 10346A, 10200A, 9926A, 12650D, 12650D84)