Good news, I got my overhead console DTE (Distance to Empty) programmed properly for my 46 gallon Transfer Flow Diesel tank. Using TSB 04-15-10 you can reprogram the reading for any tank size listed. Unfortunately Ford never made a 46 gallon, the largest listed is 40. I understand an Excursion came with a 44, but that number isn't listed in this TSB either. Well, to make a long story short, I was able to figure out how the numbers are encoded for the various sizes. Contrary to what has been reported here earlier, you can use other numbers not listed in the Ford TSB, you just have to know how to figure out what to enter.

This may only work for the models listed in the TSB, 2003 and 2004 models. Don't know if 2005 and beyond will work, as they have the newer information center in the dash instead of the overhead console. I have the diesel tank, but this procedure should work for gas also.

To use a 46 gallon tank, simply enter the number "6A-01 01CC 0000 3169" as the first number and "6A-02 0000 0000 319D" as the second number. The second number is the same for all tank sizes, and indicates there is no second tank installed.

If anyone is interested in other sizes, I can describe how the encoding works.

 

Please explain in detail how to do this. I'll give it a try on my 05 and report back on the results.

 

Yes, please do a complete write-up on your discovery. This should be in the tech folder.

Figures a ham would break the code.


'73s
Stu

 

edit: deleted posting, please see the next one...

Moderator, please remove this if possible..

 

Ok, here is what the numbers mean. I entered the wrong number on purpose in the fourth field once, and the WDS computer would not except it, so I have some faith this method works. I went in with the DTE reading some number with my original 29 gallon programming. Going to the TSB listed 40 gallon size (the largest offered in the TSB) the DTE went up an appropriate percentage. Then reprogramming for my 46 gallon size, the DTE went up again an appropriate percentage, so it seems to work.

The first set of numbers is for the front tank, the second set of numbers is for the back tank. On any recent SD truck since 1999 or so I think there is only a single tank. The infrastructure to track two tanks is still in the system however.

The numbers are composed of 4 fields. I will use the number for the 46 gallon tank size as an example: 6A-01 01CC 0000 3169

The 6A-01 says this is for the first (front) tank. I have no idea what 6A means, but the 01 is first tank, 02 is second tank (rear) and 03 third tank etc. The WDS computer we used to do the programming asked us if there was a 6A-03 and 6A-04 number to enter. We said no as I recall.

The 01CC number is the hexadecimal code for the tank size in gallons X 10. In this case 0x01CC is 460 decimal, or 46 X 10. If you look at the listed tank sizes in the TSB, you can see this relationship quite clearly. There is some minor deviation though, for example the standard short bed tank of 29 gallons has 0x012C, which in decimal is 300, or 30 X 10 gallons. The 36 gallon tank shows 0x0166, which is 358, or 35.8 gallons.

The 0000 number always seems to be all zeros, and I have no idea what it means, but just leave it at all zeros.

The fourth number is the real mystery. It seems to be treated as a check of some kind, to validate that you entered the entire number correctly (kind of like a checksum for those of you that do algorithms). What seems to work here is to always use 31 as the first two digits, and to take the last two digits of the second number (01CC, so use just CC) and add 0x9D to it (why 0x9D, I have no idea) then truncate the resulting product to just the lower 2 digits.

So in hex math you have 0x01CC which becomes just 0xCC + 0x9D = 0x169 truncates to 0x69 as the last two digits, with 0x31 as the first two digits or 3169.

If we do this for the 40 gallon size you have 0x0190 which becomes just 0x90 + 0x9D = 0x12D, which becomes just 2D, and when combined with 31 becomes 0x312D. If you look at the TSB listed 40 gallon tank, you see 312d as the fourth field.

There does seem to be one exception to this math however, and that is for the 19 gallon tank. My math indicates the fourth number should be 3151, when in fact the listed number is 3150. Hmm, can't explain that one. Only thing I see different is that the 19 gallon tank is the only size that doesn't have a "1" in the second digit of the second field. This could explain the off by one problem.

 

Where do I enter the code and how do I get there?


Thanks!

 

To enter this code, you need to have access to a Ford recent computer programmer. These are only available at the dealer (usually). The TSB I referenced has all the details on how to enter the number(s). I used a WDS computer, but have since been told by my mechanic at Ford that this computer has been superceded by something else that is PDA (Personal Digital Assistent) based. The same computer that does the PCM reflashes is what this procedure needs.

I don't know if a dealer will willingly do this procedure or not, I have made friends with a mechanic at my dealership, and he kind of did it under the table for me