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Home >> Ford >> 1990 >> Bronco II 4WD, Standard, M5OD-R1 >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Tests W/Codes >> EEC-IV Backup Strategies & Effect On Mil Light >> Hardware Limited Operational Strategy (HLOS)
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Hardware Limited Operational Strategy (HLOS)

The HLOS mode is a major ECA backup strategy used when extreme system or sensor failures exist. Without HLOS, the ECA could not operate the vehicle.

In HLOS mode, all ECA software operations have stopped and the processor is running on hardware control only. System control is strictly minimal to allow the vehicle to "limp-in" for repair. Driveability concerns will be present.

NOTE: The ECA will not output any self-test service codes in this mode.