Interpret trouble codes for Ford vehicles by using the OBD Codes website or the Check Engine Light website. Each site provides a list of codes unique to Ford vehicles and an explanation of each code's meaning.
A common Ford error code is P1039, which means the vehicle's speed signal is working improperly or not at all. Another signal-related error is P1051, which means the brake signal is not working properly. The error code P1504 indicates that there is a malfunction in the vehicle's intake air control circuit.
Some errors have identical meanings. For example, error codes P1233 and P1234 both mean the driver module for the vehicle's fuel pump is offline, whereas error codes P1235 and P1236 mean the vehicle's fuel pump control is now out of range. Error codes P1237 and P1238 indicate that the secondary circuit for the vehicle's fuel pump is faulty.
Sometimes, consecutive error codes are a clue to the specific part of the vehicle that is malfunctioning. Error code P1352 means that the primary circuit for ignition coil A is faulty. Error code P1353 means the same thing for coil B, and P1354 and P1355 represent the same error for coils C and D, respectively.