We also picked up an AEV ProCal module to reset the factory computer to the new tire diameter we were able to run with the 2 1/2-inch AEV lift kit we installed earlier. Using just nine dip switches on the AEV ProCal, we were able to set the tire size, recalibrate the tire pressure monitoring system, activate daytime running lights, add “one touch” turn signals, and enable a temporarily increased engine idle speed for winching. The AEV ProCal can also read and clear engine codes and help alignment techs align for optimal ESP performance. Just flip the switches in the right order and plug it into the OBDII port. The Jeep beeps twice, and it’s done.