The engine P2685 Code cannot be ignored and by the meaning of the code, you can solve the car engine problem. Symptoms of the car engine problem may comprise a kept trouble/error code, a hard or no begin condition, decreased fuel efficacy, rough running engine, engine misfire, and a general lack of power. If this code is kept, and a service engine soon lamp has not yet been illumined, the error code may be exposed as pending. Indicators and stored codes that are current as a response to a message failure are often misdiagnosed and repaired as the reason of the problematic. Clearly, this leads to an ineffective repair.