Ford published the following on 3/26 to answer some questions regarding the recall. It may clear up some confusion here, as well:
"Questions and Answers
Q1. Is this a safety recall?
A1. Yes, this is a Ford-initiated voluntary safety recall.
Q2. What is the cause of the tailpipe issue?
A2. In rare instances, the diesel particulate filter can generate excessive temperatures that could result in flame at the tailpipe.
Q3. What causes the excessive temperatures in the diesel particulate filter?
A3. A build up of hydrocarbons within the filter. Under normal circumstances, the diesel particulate filter collects particulate matter from the exhaust and then safely burns it to clean the filter. A build up of hydrocarbons in the filter may cause higher temperatures than necessary for cleaning.
Q4. What is the source of the hydrocarbons and how do they reach the filter?
A4. Hydrocarbons are found in fluids such as engine coolant, engine oil and diesel fuel. Normally, these fluids do not reach the exhaust. However, in rare circumstances, a leak within the engine could cause these fluids to enter the exhaust system and reach the filter.
Q5. How does fuel or oil reach the exhaust system?
A5. Some possible examples are a fuel injector stuck open or a leaking turbo shaft seal.
Q6. What are potential symptoms a driver may notice if they experience this concern before the recall is performed?
A6. In the rare case that vehicle owners experience this concern, the Check Engine indicator lamp in the instrument cluster may illuminate, and they may note a lack of power or rough engine operation. They may also hear abnormal noise from the engine or the exhaust and possibly see white smoke or a flame emitting from the exhaust tailpipe.
Q7. After the recall repair is performed, what symptoms will the customer notice if the PCM detects excessive heat from the DPF?
A7. The system acts to prevent any flame from emitting from the tailpipe. The software will reduce fuel flow and air flow to the engine to allow the diesel particulate filter to cool. If an over temperature event occurs, the driver of the vehicle will notice the following:
1. The Check Engine indicator lamp in the instrument cluster will flash, warning the driver to pull over to the side of the road as soon as safely possible.
2. Engine RPM will be reduced to idle after 3 – 5 seconds. Power steering and power braking assist will not be affected but the customer will not be able to accelerate the vehicle beyond idle speed.
Q8. Have there been any reports of fires caused by a Super Duty?
A8. As of the date of this publication, we received a single report of a grass fire, with no injuries. We have received only three reports to date of flame from the tailpipe across the U.S. and Canada.
Q9. I have heard that installing the new PCM program could cause the ABS light or Check Engine light to remain illuminated?
A9. Many dealers have completed the PCM reprogramming using IDS without any concerns. We have identified a few common concerns that have been experienced. Here are some tips to follow:
1. Make sure that your IDS is updated to release 48.5 Patch 3 or later. You can verify your level by viewing the "System Utilities" screen.
2. If the correct last 8 digits of the VIN cannot be viewed from the vehicle ID screen on the IDS, please enter them manually.
3. If after reprogramming you have hard fault P1639 or P1635, please perform Programmable Module Installation for the PCM in the same IDS session. Do not delete the current session as this will take longer to correct.
4. Be sure to pull and clear all Continuous Memory Diagnostic Trouble Codes (CMDTC's) after the PCM reprogramming is completed. If you don't do this, it is possible that indicator lights could be illuminated.
5. When you have completed the PCM reprogramming on an affected vehicle, be sure to close the session before connecting to the next vehicle. Do not use the same IDS session to reprogram several different trucks. Every vehicle needs to have its own IDS session to ensure the correct information is used to reprogram each PCM.
Q10. When will you begin mailing customer letters?
A10. We expect to begin mailing customer letters the week of April 2, 2007.
Q11. Should owners stop driving their vehicles?
A11. We are not instructing customers to stop driving their vehicles. Customers should, however, take their vehicles to their Ford dealer to receive the software update as soon as possible.
Q12. Will the condition occur when the vehicle is shut off?
A12. No, the condition does not occur when the engine is off.
Q13. Are there any other changes associated with this calibration that a customer may notice?
A13. Yes. This calibration will also address other drivability and Check Engine indicator light concerns that could be experienced during normal operation. Please refer to Special Service Message (SSM) 19683 for further details."
Forgot to add, here's the text from SSM 19683:
"19683 6.4-CALIBRATION UPDATE-DTC'S P132B,P0128,P0684,P0231,P2291,P2459,P0500,P0102, P242C,P242D,P2032,P2033. A/C INOP, MANUAL TRANS CONCERNS, AND DPF IMPROVEMENTS.
2008 F-SUPER DUTY WITH 6.4L ENGINE BUILT BEFORE 3/9/07; FSA 07S49 CALIBRATION UPDATES ALSO ADDRESS THE FOLLOWING DTC'S: P132B, P0128, P0684, P0231, P2291, P2459, P0500, P0102; AND DIESEL PARTICULATE FILTER SYSTEM CODES P242C, P242D, P2032, P2033 - WHICH WILL NOW INITIATE A BLINKING MIL, REDUCE ENGINE POWER, AND REDUCED IDLE QUALITY TO ALERT THE USER OF A FAULT REQUIRING VEHICLE SERVICE. ADDITIONAL IMPROVEMENTS INCLUDE: DRIVABILITY DURING DPF REGENERATION INCLUDING HIGH ENGINE SPEED DURING CLUTCH OPERATION ON MANUAL TRANSMISSION EQUIPPED VEHICLES, BUCK/JERK/SURGE, TIP IN/TIP OUT FEEL FOR MANUAL TRANSMISSION, AND A/C CONCERNS WITHOUT DTC'S AT COLD AMBIENT OR IN PDI. REPROGRAM ECM PER FSA PRIOR TO DIAGNOSIS AND CLEAR ALL DTC'S AFTER PROGRAMMING. FOR DTC'S GENERATED AFTER REPROGRAM, FOLLOW NORMAL PROCEDURES."