It doesn't say anything about where they source the pressure sensor/transducer from. I would suggest stopping by your local dealer and picking one up from them and installing it. I'm willing to bet that will fix your problem.
His: '00 WJ 4.7 Limited- Zone 4" SA lift, JKS BPE's
Hers: '03 WJ 4.7 Laredo- IRO 3", 245/75/16 Duratracs, Bilstein Shocks, JKS TB w/KOR Bushings, Rusty's A-Arm Spacer, CORE4x4 Adjustable Front Control Arms, Dynomax Exhaust, RB1 Nav -Coming Soon- Overland Rock Rails