Well, I finally figured out how to reprogram (for the speedo to read correctly and so on) for tire size and gear ratio changes in the 98-01 Explorers/Rangers/Mountys. I used a NGS (Factory Ford scan/program tool - no longer in use anymore) with all of its recent updates (up until last year I believe), and was able to go into the ABS system and change the settings manually. Now, as probably many of you know, I tried to go through the GEM Module to reprogram, but it would never take any of my programs/settings (http://www.explorerforum.com/forums/showthread.php?t=134477. Well, I basically back doored it going through the ABS module which is what the GEM module acually uses for the speedo. So with change the settings in the ABS module, it changes the GEM Module. Here is a helpful list:
98-01 -- Reprogramable through the GEM or ABS Module
91-97 -- Gear Change (for the transmission)
Now, Ford charges .7 hrs for a reprogram as described in the above links and in the post. It took possibly 3 minutes to change everything. Granted, I knew the Revolutions Per Mile ahead of time, but that would of taken just as long. Here is how you figure out your REVS/Mile:
Chalk Test:
Mark your tire at the bottom with a chalk pencil or something visible (also mark on the pavement) and then roll forward until it has made a full revolution and mark another mark on the pavement. Then measure between the two marks and that is 1 revolution. In my case mine came out to be 8' and 5"s which in turn changes to 101"! So now what? Here is something helpful:
1 mile = 5280 ft x 12" = 63,361 inches
Now, devide 63,361 inches by 101 inches (your one revolution) and you will end up with 627.33 Revs/Mile. Obviously each vehicle will be different (i.e. tire size), but my set up was 33" tall tires with 4.56:1 Gear Ratios.
Well, now that you have all these numbers what do you do? Well, do the following (in the NGS):
1. SELECT: SERVICE BAY FUNCTIONS
2. SELECT: ABS
3. SELECT: TIRE SIZE/AXLE RATIO CONFIGURE
a. The NGS Tester will display "DETERMINING MODULE PROTOCOL, PLEASE WAIT"
b. When NGS Tester is ready, press {TRIGGER} to continue.
4. ENTER TIRE SIZE/REVOLUTIONS PER MILE (REV/MILE)
5. SELECT: DONE
I know that not many of you have a NGS, but this is just so you know what happens when whoever does the reprogramming is doing and you can stay up to date. My speedo is in within 1-2mph! Use to be 5mph+ at 0-45mph and 10mph+ 55mph+! It's a wonderful thing now.
-Drew
98-01 -- Reprogramable through the GEM or ABS Module
91-97 -- Gear Change (for the transmission)
Now, Ford charges .7 hrs for a reprogram as described in the above links and in the post. It took possibly 3 minutes to change everything. Granted, I knew the Revolutions Per Mile ahead of time, but that would of taken just as long. Here is how you figure out your REVS/Mile:
Chalk Test:
Mark your tire at the bottom with a chalk pencil or something visible (also mark on the pavement) and then roll forward until it has made a full revolution and mark another mark on the pavement. Then measure between the two marks and that is 1 revolution. In my case mine came out to be 8' and 5"s which in turn changes to 101"! So now what? Here is something helpful:
1 mile = 5280 ft x 12" = 63,361 inches
Now, devide 63,361 inches by 101 inches (your one revolution) and you will end up with 627.33 Revs/Mile. Obviously each vehicle will be different (i.e. tire size), but my set up was 33" tall tires with 4.56:1 Gear Ratios.
Well, now that you have all these numbers what do you do? Well, do the following (in the NGS):
1. SELECT: SERVICE BAY FUNCTIONS
2. SELECT: ABS
3. SELECT: TIRE SIZE/AXLE RATIO CONFIGURE
a. The NGS Tester will display "DETERMINING MODULE PROTOCOL, PLEASE WAIT"
b. When NGS Tester is ready, press {TRIGGER} to continue.
4. ENTER TIRE SIZE/REVOLUTIONS PER MILE (REV/MILE)
5. SELECT: DONE
I know that not many of you have a NGS, but this is just so you know what happens when whoever does the reprogramming is doing and you can stay up to date. My speedo is in within 1-2mph! Use to be 5mph+ at 0-45mph and 10mph+ 55mph+! It's a wonderful thing now.
-Drew
