In following up to determining our "gear ratio", I found another code in the glove box, the JL4.
After having our truck VIN run, I see on the list, JL4 CONTROL ACTIVE BRAKE ACTIVE BRAKE CONTROL(JL4)
A. When we first got the truck, we had a mechanic add a Pilot brake controlling unit. Does that mean the truck now has 2??
B. If it has 2, does one interfere with the other?
Thanks for your help. I am trying to work out all bugs before a long trip.