67 Pa. Code § 171.82
An automatic audible backup alarm, if used, shall be installed behind the rear axle. The backup alarm shall comply with SAE Standard J994b. See Appendix A.
The provisions of this § 171.82 issued under the Vehicle Code, 75 Pa.C.S. § § 4103, 4551—4553 and 6103.
The provisions of this § 171.82 adopted September 13, 1996, effective September 14, 1996, 26 Pa.B. 4411.