Chrysler Repair: 99 T& C check engine light on, no codes. Why?, chrysler town and country, service engine soon light

Question
Hello Roland,
Service Engine Soon light comes on most of time on 1999 AWD 3.8L Chrysler Town and Country ~95k miles.  Using digital display code readout only gives flashing code "55" indicating end of codes.  Engine runs fine.  Have checked for tight fuel cap.  Any ideas please on what else to investigate?  Many thanks!

Answer
Hi Ron,
I believe that the light's illumination is indicating a trouble that it not programmed to be coded in such a manner as be readout on digital display. It could mean a transmission issue or a subtle engine performance/emission level concern. If there is an Autozone or other parts store nearby you might be able to borrow a diagnostic reader that plugs into a receptacle under the dash which will give you a more thorough readout of the system and thus a possible P---- code to respond to. Alternatively a shop will do a readout for under $50 in most cases.
Let me know the code(s) and we can take it from there.
Roland