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Forscan experts? No fog lights!

  • Thread starter Thread starter optionizerSS
  • Start date Start date Aug 26, 2025
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lenko

Member
Feb 28, 2006
64
1
9
Southern Alberta
Sep 7, 2025
#21
  • Sep 7, 2025
  • #21
My Gem open/close setting shows "On" can you click on yours and change it. Mine can be changed from ON to OFF and back to ON.
 
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optionizerSS

Active Member
Apr 23, 2023
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38
Sep 7, 2025
#22
  • Sep 7, 2025
  • #22
lenko said:
My Gem open/close setting shows "On" can you click on yours and change it. Mine can be changed from ON to OFF and back to ON.
Click to expand...
I don't think mine has an on/off. IIRC you have to type in the value for what you want to change. like there is no list or anything
 

lenko

Member
Feb 28, 2006
64
1
9
Southern Alberta
Sep 7, 2025
#23
  • Sep 7, 2025
  • #23
Unfortunately there is not much information about programming older Mustangs. Looking at the GEMs of a V6 (No Fogs) and a GT may show a difference, but there are so many lines that makes it almost prohibitive to research. Here's another site you can look at and see if it's helpful: https://www.startmycar.com/us/ford/mustang/info/fusebox/2006/fog-light-fuse#problems-article
 

lenko

Member
Feb 28, 2006
64
1
9
Southern Alberta
Sep 7, 2025
#24
  • Sep 7, 2025
  • #24
Here's another site that may be useful. The post by LaForge showing Karsten's post speaks of fogs: https://forscan.org/forum/viewtopic.php?f=6&t=3119&hilit=05+to+09+Mustang&start=10
 
Last edited: Sep 7, 2025
O

optionizerSS

Active Member
Apr 23, 2023
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Sep 7, 2025
#25
  • Sep 7, 2025
  • #25
Thanks
 

Mustang5L5

That is…until I whipped out my Bissell
Mod Dude
Feb 18, 2001
43,259
17,943
224
Massachusetts
Sep 9, 2025
#26
  • Sep 9, 2025
  • #26
Was this a brand new module or a used unit?

ForScan generates a list for some selectable features. They will list it under the menu item that does not constain (as_built format)



For example above. This is the same module. The top one will have all the various bits and numbers broken out, the bottom one will have some of the features in list format, but not all. The menu usually self populates if folks have found what bits do what and report it to forscan. It gets rolled into the next revision.

I assume the old module is dead? If it's not, you can plug it back in and download the as built data from that module and save it to your computer. You would go into the correct module in the as built format menu, and select save to save the module configuration from the module to your hard drive.

If the module is dead, or you do not want to reinstall it, you can download your as_built direct from Ford

https://www.motorcraftservice.com/SetCountry?returnUrl=%2FAsBuilt

You enter your VIN and it will provide you with the right coding for each module.

If by any chance Roush modified the as_built, you might want to try and pull it from the module itself, if it's able to be read.


Once you have the correct as_built downloaded, open up forscan and navigate to the correct module. Again, you want the as_built format menu. At the bottom, hit load all and load up the as_built you downloaded from Ford. It should change the values around on the screen. After this, hit "write all" and that will write the as-built to the new module.

I know that's a pain, but it may be quicker to just pull and write the as built to the module vs trying to find what single bit of code did the fog lights. You might even be able to pull the as built from your other Roush and load it onto the module. Regardless...save the as-built currently on the module now, as you know it works other than the fog lights.



Anyone messing with forscan should just back up all their modules to their harddrive anyway. Load up each module and save it and then store it in a safe place. If that module ever craps the bed, or you make changes that really fudged up how the vehicle is behaving, you can just load your original file up and be done.
 
Last edited: Sep 9, 2025
O

optionizerSS

Active Member
Apr 23, 2023
204
37
38
Sep 9, 2025
#27
  • Sep 9, 2025
  • #27
Mustang5L5 said:
Was this a brand new module or a used unit?

ForScan generates a list for some selectable features. They will list it under the menu item that does not constain (as_built format)



For example above. This is the same module. The top one will have all the various bits and numbers broken out, the bottom one will have some of the features in list format, but not all. The menu usually self populates if folks have found what bits do what and report it to forscan. It gets rolled into the next revision.

I assume the old module is dead? If it's not, you can plug it back in and download the as built data from that module and save it to your computer. You would go into the correct module in the as built format menu, and select save to save the module configuration from the module to your hard drive.

If the module is dead, or you do not want to reinstall it, you can download your as_built direct from Ford

https://www.motorcraftservice.com/SetCountry?returnUrl=%2FAsBuilt

You enter your VIN and it will provide you with the right coding for each module.

If by any chance Roush modified the as_built, you might want to try and pull it from the module itself, if it's able to be read.


Once you have the correct as_built downloaded, open up forscan and navigate to the correct module. Again, you want the as_built format menu. At the bottom, hit load all and load up the as_built you downloaded from Ford. It should change the values around on the screen. After this, hit "write all" and that will write the as-built to the new module.

I know that's a pain, but it may be quicker to just pull and write the as built to the module vs trying to find what single bit of code did the fog lights. You might even be able to pull the as built from your other Roush and load it onto the module. Regardless...save the as-built currently on the module now, as you know it works other than the fog lights.



Anyone messing with forscan should just back up all their modules to their harddrive anyway. Load up each module and save it and then store it in a safe place. If that module ever craps the bed, or you make changes that really fudged up how the vehicle is behaving, you can just load your original file up and be done.
Click to expand...
Yeah I was thinking about that. I'm thinking Roush may have had to modify it when they had it. I still have the old module and I did download the files from it but it was so long ago I'd want to do it again to be sure i'm using the correct file. i also have another 2005 Roush but its a coupe with a manual trans so won't be exactly the same but if i knew which one was for the fog lights i'd be able to copy those over. and yeah the replacement was used. new ones haven't been available for years
 

Mustang5L5

That is…until I whipped out my Bissell
Mod Dude
Feb 18, 2001
43,259
17,943
224
Massachusetts
Sep 9, 2025
#28
  • Sep 9, 2025
  • #28
I can't actually find a 2005+ Mustang ForScan spreadsheet that lists out all the changes and bits of code identified.

A more complex way to do this, which is what i've done in the past is to hop on Ebay and look at cars with the various features you want to enable and find a vehicle that doesn't have it. You can get the VIN from each and go to the above site and pull the as_built for that vehicle. A vehicle with fog lights, and one without. Then, you compare the differences between them and try changing the bits of code to see what happens. A lot more labor intensive but this is how those spreadsheets and menus in forscan get built.

If this was my vehicle, i would download the as built from the old module and load it to the new one. I know it's easier to just change that one 1 bit for the fog lights...but you'd have to put the time in to find what that bit to change actually is.
 
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optionizerSS

Active Member
Apr 23, 2023
204
37
38
Sep 9, 2025
#29
  • Sep 9, 2025
  • #29
True. This will be a winter project. For one I don't want to screw anything up during cruising season and two is I have been unemployed for 5 months so I have bigger fish to fry right now but I appreciate the ideas and opinions. If it was an easier thing I'd do it now but it can wait for a couple more months.
 

lenko

Member
Feb 28, 2006
64
1
9
Southern Alberta
Sep 9, 2025
#30
  • Sep 9, 2025
  • #30
Here's an Asbuilt compare of one 2005 GT and two 2005 V6 with no apparent fog lamps. It seems the difference show up in the 726-01-01 line. Maybe this will help.
 
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optionizerSS

Active Member
Apr 23, 2023
204
37
38
Sep 9, 2025
#31
  • Sep 9, 2025
  • #31
Awesome. I’ll take a look. Thanks
 
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optionizerSS

Active Member
Apr 23, 2023
204
37
38
Dec 28, 2025
#32
  • Dec 28, 2025
  • #32
Well about time to get on this project. Started a new job about 6 weeks ago and the cars are put away for the winter so time to focus on getting them ready for next season.
I think my initial plan is to compare the data between the 2 cars. I do have the old files from the original BCM that I saved awhile back so I might do the comparison trick out of curiosity but if nothing stands out I might just upload the old files.
Might start on this tomorrow after work. I have not saved the ones from the coupe yet so will start with saving those then start comparing.
Any last words of advice?
 

lenko

Member
Feb 28, 2006
64
1
9
Southern Alberta
Dec 29, 2025
#33
  • Dec 29, 2025
  • #33
optionizerSS said:
Well about time to get on this project. Started a new job about 6 weeks ago and the cars are put away for the winter so time to focus on getting them ready for next season.
I think my initial plan is to compare the data between the 2 cars. I do have the old files from the original BCM that I saved awhile back so I might do the comparison trick out of curiosity but if nothing stands out I might just upload the old files.
Might start on this tomorrow after work. I have not saved the ones from the coupe yet so will start with saving those then start comparing.
Any last words of advice?
Click to expand...
Don't have anything else to add - good luck.
 
O

optionizerSS

Active Member
Apr 23, 2023
204
37
38
Feb 16, 2026
#34
  • Feb 16, 2026
  • #34
Update! So decided to get on this yesterday. Well my Forscan extended license had expired...lol. So renewed it and tried again today. Got some help from my old buddy ChatGPT...lol. He said to change one bit in the file from a 2 to a 6 so did that and still no luck. He then suggested I had the wrong BCM and that one could not be programmed for fog lights but I confirmed both were identical part numbers. He then wanted me to troubleshoot the relay which I said I had already swapped the fog light relay from our other 2005 and no luck. So I pulled the relay then turned the fog lights on and checked voltage. Plugged the relay back in and they started working. Walked away for about 15 minutes and came back and again no fog lights so I pulled the relay again and when I plugged it back in they started working again. After close inspection I noticed a little rust color on the fuse box plastic next to the relay terminals so 99.9% sure that is my issue. Next step is to clean the terminals and while I'm at it clean all terminals in that fusebox.
 
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Noobz347

Stangnet Facilities Maint Tech... Er... Janitor
Admin Dude
Jan 4, 1985
43,096
21,279
234
Box behind Walmart
Feb 19, 2026
#35
  • Feb 19, 2026
  • #35
I use the crap out of this stuff:


https://www.amazon.com/Hosa-D5S6-Contact-F5S-H6-FaderLube/dp/B00HNV7WI2/ref=sr_1_1?crid=1ALZNU5QWTA2H&dib=eyJ2IjoiMSJ9.UbkTjzoOgNAHFQS4VKBQ9oX7q_lEdfRomNNfoUXeT2Tqz8CA5OXQMekzEQOtRNXr5VE1HvdQZj06gnxQYX8v2m9w2HyqwR5j2FJ_eR9bjxZpScuMjEtleFY3KYsKhPRsbMbQ5qhcY3taenepY3J1pb67l1tqzTKC6bPzNSkm8jOXzjen9SOVyr3IkrGJOXXQpvLBtrOsnK9S5DYWflInQQMICt-quLOJZLsIn1DFeoPw2vwaasA22e1Z7CHiK1aRZv2AOs1agfQuXfGER7h6Mh5G0ZfINHFlSudWMCcJHBQ.mkdjWDi3NeHxWgJtyx93PI4nFT1A3Ap5NM2nDV1Sl68&dib_tag=se&keywords=deoxit&qid=1771519832&sprefix=deoxit%2Caps%2C180&sr=8-1
 
O

optionizerSS

Active Member
Apr 23, 2023
204
37
38
Feb 19, 2026
#36
  • Feb 19, 2026
  • #36
Noobz347 said:
I use the crap out of this stuff:


https://www.amazon.com/Hosa-D5S6-Contact-F5S-H6-FaderLube/dp/B00HNV7WI2/ref=sr_1_1?crid=1ALZNU5QWTA2H&dib=eyJ2IjoiMSJ9.UbkTjzoOgNAHFQS4VKBQ9oX7q_lEdfRomNNfoUXeT2Tqz8CA5OXQMekzEQOtRNXr5VE1HvdQZj06gnxQYX8v2m9w2HyqwR5j2FJ_eR9bjxZpScuMjEtleFY3KYsKhPRsbMbQ5qhcY3taenepY3J1pb67l1tqzTKC6bPzNSkm8jOXzjen9SOVyr3IkrGJOXXQpvLBtrOsnK9S5DYWflInQQMICt-quLOJZLsIn1DFeoPw2vwaasA22e1Z7CHiK1aRZv2AOs1agfQuXfGER7h6Mh5G0ZfINHFlSudWMCcJHBQ.mkdjWDi3NeHxWgJtyx93PI4nFT1A3Ap5NM2nDV1Sl68&dib_tag=se&keywords=deoxit&qid=1771519832&sprefix=deoxit%2Caps%2C180&sr=8-1
Click to expand...
Yeah I have heard good things about that stuff
 
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