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Home >> Ford >> 1991 >> Bronco 4.9 Y, Standard, M5OD-R2 >> Repair and Diagnosis (Single Page) >> Engine Performance >> Theory and Operation >> Engine Controls - Theory & Operation >> Computerized Engine Controls >> Electronic Control Assembly (ECA)
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Electronic Control Assembly (ECA)

During system operation, ECA transmits electrical reference signals to engine sensors and analyzes return signals to determine engine operating conditions. See Fig 1. If a sensor or actuator fails, ECA initiates an alternative strategy, allowing vehicle to maintain driveability. This strategy is called Failure Mode Effects Management (FMEM).

The CHECK ENGINE light will illuminate and remain on whenever FMEM is in operation. The ECA, overriding failed component with a FMEM substitute operation value, continues to monitor failed sensor. Should signals from faulty sensor return to within operational limits, ECA will cancel FMEM and resume control based on sensor signals.

ECA LOCATION

Application Location
Aerostar Under Left Instrument Panel
Bronco & "F" Series Behind Left Kick Panel
"E" Series Under Right Instrument Panel
Explorer & Ranger Behind Right Kick Panel
Fig 1: EEC-IV System Component Diagram (Typical)
G90J15981Courtesy of FORD MOTOR CO.
NOTE: Components are grouped into 2 categories. The first category is INPUT DEVICES, covering components which control or produce voltage signals monitored by the ECA. The second category is OUTPUT SIGNALS, covering components controlled by the ECA.