339.13 ENGINE BRAKING.
   (a)    No person shall use an engine decompression braking system, or use an engine, transmission, or associated component parts, to stop, slow or brake a commercial motor vehicle within the City.
   (b)    It shall be an affirmative defense to a violation of section (a) hereof that the violation was in response to a bona fide traffic safety emergency.
   (c)    "Commercial motor vehicle" shall have the same meaning as set forth in Section 341.01(d) of this Code.
   (d)    The prohibition set forth in subsection (a) hereof is subject to the same exemptions as set forth in Section 341.02 of this Code.
 
   (e)    Whoever violates this section is guilty of a minor misdemeanor.