Ford OBD Codes: Meaning & Fixes

P0174 Powertrain The cylinder bank without cylinder 1 is running lean even with the maximum fuel correction… Moderate P0300 Powertrain The engine computer sees misfires that jump between cylinders or hit several cylinders at once. High P0304 Powertrain Cylinder 4 is misfiring. Its end or rear position makes water, oil and intake leaks common… Moderate P0430 Powertrain The bank 2 converter on a V6, V8 or split-exhaust engine isn't cleaning the exhaust well enough. Low P0301 Powertrain Cylinder 1 is repeatedly failing to fire. The cause is almost always its coil, plug, injector… Moderate P0302 Powertrain Cylinder 2 keeps misfiring. On inline engines it's a middle cylinder, so rule out coolant… Moderate

P0302 Powertrain Cylinder 2 keeps misfiring. On inline engines it's a middle cylinder, so rule out coolant… Moderate P0303 Powertrain Cylinder 3 is misfiring. Check whether it misses at idle or under load before you blame… Moderate P0304 Powertrain Cylinder 4 is misfiring. Its end or rear position makes water, oil and intake leaks common… Moderate P0307 Powertrain Cylinder 7 is misfiring. On GM and Hemi V8s it's a cylinder-deactivation cylinder, so check… Moderate P0308 Powertrain Cylinder 8 is misfiring. It's a rear V8 cylinder against the firewall, so its plug is often… Moderate P0316 Powertrain The engine misfired right after starting, when the catalytic converter is cold and emissions… Low P0320 Powertrain The computer lost the engine speed (rpm) signal. The engine can stall suddenly or refuse… High P0346 Powertrain Bank 2's cam signal arrives out of position. On V6/V8s that often means a bank 2 chain, guide… Moderate P0354 Powertrain Coil D, normally the one on cylinder 4, failed its circuit check. It often shows up right after… Moderate P0401 Powertrain The ECU opened the EGR system but saw too little effect — the valve or its passages are likely… Low P0402 Powertrain More exhaust is being recirculated than the ECU asked for, usually because the EGR valve won't… Moderate P0405 Powertrain The EGR position or pressure sensor signal is stuck near zero volts, below its normal operating… Low P0430 Powertrain The bank 2 converter on a V6, V8 or split-exhaust engine isn't cleaning the exhaust well enough. Low P0446 Powertrain The canister vent valve isn't doing what the ECU commands — electrically or because the vent… Minor P0455 Powertrain The fuel vapor system can't hold vacuum at all — check the gas cap first, then hoses and valves. Low P0456 Powertrain The EVAP system has a tiny leak, about 0.020 inch — the hardest EVAP leak to find, and often… Minor P0457 Powertrain The EVAP leak test found the system wide open — almost always a loose, missing or worn gas cap. Minor P0471 Powertrain The exhaust backpressure reading doesn't match what the computer expects; the sensor tube… Moderate P0496 Powertrain Vapor is being drawn into the engine while purge is commanded off: almost always a purge valve… Low P0505 Powertrain The engine computer can't hold idle speed where it wants it – usually a dirty or sticking idle… Low P0603 Powertrain The engine computer lost its learned memory – usually after a battery disconnect or a bad… Low P0606 Powertrain The engine computer failed its own internal self-test – check its power and grounds before… Moderate P0627 Powertrain The PCM's fuel pump command line has no complete circuit – a dead relay coil, open wire, fuse… Moderate P0670 Powertrain The engine computer can't properly control or hear back from the diesel's glow plug control… Low P0671 Powertrain The glow plug in cylinder 1 or its wire isn't drawing normal current. Usually the plug itself… Low P0705 Powertrain The computer can't make sense of the gear selector position signal – P, R, N, D may be misread. Moderate P0706 Powertrain The range sensor works electrically, but its reading doesn't match where the lever and gears… Moderate P0720 Powertrain Electrical fault in the output shaft speed signal – shift timing and sometimes the speedometer… Moderate P0722 Powertrain The output speed sensor sends nothing while the car moves – shifting and often the speedometer… Moderate P0732 Powertrain Second gear isn't holding: the input-to-output speed ratio in 2nd is outside the expected range. Moderate