Hardware Limited Operation Strategy (HLOS)

This system of special circuitry provides minimal engine operation should the PCM [mainly the central processing unit (CPU) or EEPROM] stop functioning correctly. All modes of self-test are not functional at this time. Electronic hardware is in control of the system while in HLOS.

HLOS allowable output functions:

• Spark output controlled directly by the CKP signal.
• Fixed fuel pulse width synchronized with the CKP signal.
• Fuel pump relay energized.
• Idle speed control output signal functional.

HLOS disabled outputs to default state:

• EGR solenoids
• No torque converter clutch lock-up

PCM location

• In the engine compartment, at the rear of the engine above the center of the cowl