Hardware Limited Operation Strategy (HLOS)

This system of special circuitry provides minimal engine operation should the PCM, mainly the central processing unit (CPU) or electronically erasable programmable read only memory (EEPROM), stop functioning correctly. All modes of self-test are not functional at this time. The electronic hardware is in control of the system while in HLOS.

HLOS Allowable Output Functions:

• Spark output controlled directly by the crankshaft position (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:

• Exhaust gas recirculation (EGR) solenoids
• No torque converter clutch lock-up