Speedo calibration

[trueblue52]

I have a 1998 Ford Ranger 2wd I am changing from 14" wheels to 15" and also putting on 30"x9.50 tires. How do I recalibrate speedo do I need to.

 

[rwenzing]

For 98~2000 Rangers, the tire size adjustment for the speedometer lives in one of two modules depending on which type of ABS you have:

RABS: GEM
4WABS: 4WABS Module

Ford dealers have the special tool to access these modules and modify their settings through the truck's module communications network.

~~~~~~~~~~~~~~~~~~~~~~

There are also aftermarket conversion boxes that can be installed in the speed signal wire to adjust the speedometer. They cost about $100~200.

http://www.bluegauges.com/prod_yellow_box.htm

 

[BrooklynBay]

Welcome to this forum! This link has information which you should find useful: http://www.explorerforum.com/forums/showthread.php?t=146122

 

[rwenzing]

Welcome to this forum! This link has information which you should find useful: http://www.explorerforum.com/forums/showthread.php?t=146122

The link has info that applies directly to 98~2001 Explorers which all had 4WABS. 98~2000 Rangers were RABS standard with 4WABS optional and the corrections are made in either the GEM or the 4WABS module respectively. 2001 Rangers have the speedometer correction for tire diameter/axle ratio in the PCM.