What Is An Efi Code One On A 2003 Harley Road King

Electronic fuel injection allows gasoline into a Harley engine.

Harley-Davidson Road Kings with wide whitewall tires over steel-laced wheels are reminiscent of the 1950s, a time prior to electronic fuel injection (EFI). The EFI 1 diagnostic code may be concurrent with a manifold absolute pressure (MAP) code in the 2003 Harley-Davidson touring family of motorcycles.

Sequential Port Fuel Injection System

EFI systems in Harley-Davidson motorcycles released after 2001 determine how much fuel to inject into the engine by reading the engine load sensor, known as the intake manifold vacuum sensor. EFI is controlled by an electronic control computer chip which determines how much fuel to allow into the engine.


The MAP sensor communicates intake manifold pressure to the engine control module (ECM). The ECM is updated when the EFI is changed to maintain the correct air/fuel mixture. Ignition timing might change after cleaning the electronic fuel injection. The air filter should be inspected every 5000 miles or more often if you drive on dirt.

Cleaning Fuel Injection

A fuel pump, filter and regulator deliver fuel through injectors in your engine’s intake manifold. The battery must be disconnected because gasoline is highly flammable. The maxi fuse and air cleaner can then be removed and cleaned with Harley-Davidson approved air cleaner/degreaser.