Section 4 • Repair ProceduresJanuary 2013Part No. 84793 GS-84 • GS-90 4 - 655-6Engine Fault Codes -Ford ModelsHow to Retrieve Engine FaultCodesThe ECM constantly monitors the engine by theuse of sensors on the engine. The ECM also usessignals from the sensors to initiate sequential fuelinjection and make constant and instantaneouschanges to ignition timing, fuel delivery and throttleposition to maintain the engine's running conditionat its highest efficiency while at the same timekeeping exhaust emissions to a minimum. When asensor fails or returns signals that are outside ofset parameters, the ECM will store a fault code inmemory that relates to the appropriate sensor andwill turn on the Check Engine Light.Refer to Section 5, Fault Codes. Use the FordEngine ECM Fault Code Chart within Section 5 toaid in identifying the fault.1 Open the ground controls side cover.2 Pull out the red Emergency Stop button to theon position at both the ground and platformcontrols. Turn the key switch to groundcontrols.3 Quickly activate and release the start toggleswitch/button. Do not start the engine.4 Move and hold the run/test toggle switch to thetest position.Result: The check engine light should turn on.The check engine light should begin to blink.5 Continue to hold the run/test toggle switch in thetest position. Count the blinks and note theresults. Refer to Section 5, Fault Codes, fordefinition of engine fault codes.Note: Fault codes are two or three digits. Thecheck engine light will blink the first digit of a twodigit code then will pause for 1.2 seconds and thenblink the second digit. For example: the checkengine light blinks 5 consecutive times, pauses for1.2 seconds and then blinks 1 time. That wouldindicate code 51. The ECM is able to store up tosix individual fault codes. There will be a 2.4second pause between codes.Note: Once a fault code has been retrieved and therepair has been completed, the ECM memory mustbe reset to clear the fault code from the ECM. See5-6, How to Clear Engine Fault Codes from theECM.GROUND CONTROLS
