EVAP Purge Solenoid

Engine Output Controls/EVAP System

Activates the EVAP purge valve. The normal commanded state is NONE. The system will INCREASE or DECREASE the amount of EVAP purge valve opening by 10 percent increments within a range of 0-100 percent. The system remains in the commanded state until cancelled by the tool or the fuel tank pressure (FTP) exceeds 24 mm Hg (12 in H20).

EVAP Purge/Seal

Engine Output Controls/EVAP System

This control enables two functions. One function increases or decreases the amount of purge by changing the duty cycle of the purge valve and commanding the vent ON, or non-venting. The normal commanded state of both valves is NONE. The system will INCREASE or DECREASE the amount of evaporative emission (EVAP) purge valve opening by 10 percent increments within a range of 0-100 percent. The second function seals the system after using the purge function to obtain a specific amount of fuel tank pressure. When activated the purge valve is commanded to 0 percent and the vent valve is commanded ON, or non-venting. Both functions remain in the commanded state until cancelled by the tool or the FTP exceeds 24 mm Hg (12 in H20).

EVAP Vent Solenoid

Engine Output Controls/EVAP System

Activates the EVAP vent solenoid. The normal commanded state is NONE. When commanded ON, the vent valve switches to non-venting. The system remains in the commanded state unless one of the following conditions occurs:

Fuel Pump

Engine Output Controls

Controls the fuel pump relay. The normal commanded state is NONE. When commanded ON/OFF, the PCM turns the fuel pump ON/OFF. If the engine is running, and the fuel pump is commanded OFF, the engine will stall. The system remains in the commanded state until cancelled by the scan tool.

Loop Status

Engine Output Controls

Controls the system loop status. The commanded states include NONE, OPEN, or CLOSED. The normal commanded state is NONE. When commanded OPEN or CLOSED, the system remains in the commanded state until cancelled by the scan tool.

Malfunction Indicator Lamp

Engine Output Controls

Controls the malfunction indicator lamp (MIL). The commanded states include NONE, ON, and OFF. When commanded ON or OFF, the system remains in the commanded state until cancelled by the scan tool.

O2S Heater Drivers

Engine Output Controls

The commanded states include NONE, ON, and OFF. The normal commanded state is NONE. Commanding O2S heater driver 1 ON turns ON both heater driver 1 and heater driver 3. On a cold engine, with the key ON, engine OFF, the HO2S signals will continue to drop below bias when commanded ON. The system remains in the commanded state until cancelled by the tool.