Hardware Limited Operational Strategy (HLOS)
WARNING: This page does not describe the selected car, but rather 12 other vehicles, including the 1993 Mercury Tracer, 1993 Mercury Topaz, 1993 Mercury Sable, 1993 Mercury Grand Marquis, and 1993 Mercury Cougar. However, it is still accessible from the selected car via links, so may be relevant.
If a number of system or sensor failures are present and PCM is not receiving enough information to operate, PCM will switch to HLOS mode. PCM will output fixed values to allow operation of vehicle. Driveability concerns will be present. PCM will not output service codes in this mode.