1988 XJ 4.0, auto.
There are 2 brake pedal switches. The switch with the brown connector is for the brakes. The white switch is for the torque converter lock up and cruise control.
The white switch looks like it has threads on it that need adjusting. All I did was push the switch in until it bottomed out on the brake pedal arm. It went click, click. You can use an ohm meter to see if the switch is changing from closed to open or the other way around depending on the year of your jeep. I used the mt2500 scanner as it says weather the brake pedal is being pushed or not.
The torque converter stayed locked up all the way down to 1100 rpm. That will help with fuel economy. It works in 4th (OD) or 3rd gear. Letting all of the way off the throttle or adding a lot of throttle will unlock the torque converter. It will automatically lock up if nothing prevents it from doing so.