The fuel injection system (CFI, EFI or SFI), is operated along with the ignition system to obtain optimum performance and fuel economy while producing a minimum of exhaust emissions. The various sensors described in this section are used by the computer control module for feedback to determine proper engine operating conditions. As the Taurus and Sable changed through the years, so did the name of the computer control module. Depending on the year of the vehicle it was called the EEC-IV Processor, Electronic Control Assembly (ECA), Electronic Control Unit (ECU) or Powertrain Control Module (PCM). Keep in mind, that even though the name of the component may have changed, its function did not.
When dealing with the electronic engine control system, keep in mind that the system is sensitive to improperly connected electrical and vacuum circuits. The condition and connection of all hoses and wires should always be the first step when attempting to diagnose a driveability problem. Worn or deteriorated hoses and damaged or corroded wires may well make a good component appear faulty.
When troubleshooting the system, always check the electrical and vacuum connectors which may cause the problem before testing or replacing a component.