Cadillac Seville / Cadillac Eldorado Forum Discussion, What is a PO 440 code? in Past Cadillac Vehicle Discussion; Ran my codes recently, got a PO 440 code that is current. Should this be of concern? car is running ...
Ran my codes recently, got a PO 440 code that is current. Should this be of concern? car is running great. Only other codes were history, and they were TCS C1225 and C1226, which I believe to be the left front and right front hubs or bearings. Am I correct?
Automobile(s): 2002.5 F55 STS, 2014 Explorer XLT 4WD
MD Eastern Shore
Re: What is a PO 440 code?
Originally Posted by 92WHTSTS
Haven't had a gas cap error msg on the DIC, so what could this be? Like I said, car is running great.
P 0440 is a generic code that says there may be small vacuum leak in the EVAP system - it could be anything from a rusted out fill pipe to a bad vent tube to a bad tank vent solenoid/tubing, bad EVAP charcoal canister, disconnected hose at the EVAP purge solenoid. Time to remove the beauty cover and start tracing hoses. This diagram is for a 2002, but the system is essentially the same as yours. Your EVAP service port has a green cap on the tube near the fuel lines at the firewall in the engine compartm,ent.
Haven't had a gas cap error msg on the DIC, so what could this be?
The code definition includes the "GAS CAP?" terminology as a reminder. Code P0440 can be set by any one of a multitude of failures in the EVAP system ranging from failure of one the two solenoids involved to the plumbing between components.
If you are 100 percent certain the gas cap is tight (until you feel it ratchet) and the gas cap gaskets are not ruptured, more in depth diagnosis is indicated.