U3854 Chrysler Firepower or the Evaporative Emission Control System Incorrect Purge Flow is the set whenever the computer sees that there is a problem with the flow coming from the purge valve or the purge flow is not enough within the EVAP system. Other serious codes may cause this code to pop up, and they may come with dangerous drivability issues that may expose you to safety risks and cause damage to the engine in the long run.
Possible Causes :
Find out what kind of system you have and verify that voltage to the fuel level sensor is present at the fuel pump wiring harness. If the scan tool has that capability, and the scan tool can operate the IMRC valves, then the problem is either resolved and a simple code clearing is all that's left or a new PCM would be called for.
Diagnostic trouble code U3854 Chrysler Firepower is not difficult to diagnose and repair. Thus, it always pays to have a qualified technician to look after your vehicle should this error code arise.
Diagnosing this code requires the engine to be in good running shape, without unmetered air entering the engine. If other codes that relates to misfiring condition, lean running or air entering the engine is present, then you must first fix those error codes before U3854 Chrysler Firepower.
Fortunately, U3854 Chrysler Firepower is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.