On Saturday the check engine light came on. This is a 2009 Ford Fusion. My daughter had just gotten gas so I figured it was gas cap related and did not panic. On Monday we had it checked at a car parts store and the codes were: B1318 P0841 P0410 and P049 The light had stayed on in spite of gas cap tightening and driving quite a few miles. Today (Tuesday) the light has gone off. Is is possible that all those codes were "false" or have cleared on their own? I have an appointment to get this checked but was wondering what your thoughts would be. This is a "new to us" used car that we bought on Saturday.

1 Answer 1


B1318 is low battery voltage

P0841 is a code for the transmission fluid pressure sensor (TFP)

P0410 is a code for the secondary air injection system (pump malfunction)

P049 is not a valid code, they are always Ptxxx. The first digit 't' (type) is always a 0 (generic) or a 1 (OEM specific). Perhaps you meant P0449 which is EVAP vent valve/solenoid.

NONE of these codes bears any relation to the gas cap, although the '4' series codes are emissions including the evaporative system (gas cap included). But P0449 is not a small or gross leak.

It sounds like the battery voltage got low, perhaps scrambled the ECU a bit. The fact that all codes cleared in a few drive cycles is a good indication that they were phantom.

Monitor to see if they come back, but they appear to be random phantoms and not even related to each other - unless the one "real" code was the battery voltage, and the other codes are a result of the ECU fainting for a moment.

Perhaps get the battery load tested to eliminate that possibility.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.