What is a code 55 on 2000 Dodge Caravan?

A code 55 on a 2000 Dodge Caravan indicates a problem with the vehicle speed sensor (VSS). However, a code 55 is actually a generic "system test" code. It means the system is working, so there is no trouble code stored. This is confusing because some older OBD systems might show 55 as a result when no code is actually stored.

In short: You likely don't have a trouble code; the system is functioning normally and just returning "55" as a default "no codes" indicator. If you're experiencing problems with your speedometer, transmission, or other speed-related systems, you'll need to use a proper OBD-II scanner to retrieve any actual Diagnostic Trouble Codes (DTCs). A simple code reader from an auto parts store is recommended.