GM Service Manual Online
For 1990-2009 cars only

Scan Tool Output Control

Additional Menu Selection(s)

Description

A/C Relay

Engine Output Controls

Activates the A/C relay from the none, ON, and OFF position.

EVAP Purge Solenoid (PWM)

Engine Output Controls / EVAP System

Activates the evaporative emission (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 percent to 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 H2O).

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 Closed (not 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 percent to 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 Closed (not venting). Both functions remain in the commanded state until cancelled by the tool or the fuel tank pressure exceeds 24 mm Hg (12 in H2O).

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 not venting. The system remains in the commanded state unless one of the following conditions occurs:

    • Cancelled by the tool
    •  Purge is greater than 0 percent, and the fuel tank pressure exceeds 24 mm Hg (12 in H2O)

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.

Gen L-Terminal

Engine Output Controls

Controls system voltage--Command states include NONE, ON, and OFF. When commanded ON, normal system voltage output is present. When commanded OFF, system voltage output is no longer present, Ignition 1 signal continues to drop, Gen L-Terminal goes to OFF and Gen F-Terminal continues to drop.

Intercooler Pump

Engine Output Controls

Activates the pump from the none to the ON position to the OFF position.

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.

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.

Oil Life Reset

Engine Output Controls

Allows the technician to reset the remaining oil life parameter--The current oil life can be cleared and a new value, between 0-100 percent can be inserted with the numeric keys.

Front O2 Sensor Heater

Engine Output Controls

Activates the following heated oxygen sensor (HO2S) heater:

HO2S sensor 1

The commanded states include NONE, ON and OFF. Commanding O2S heater driver 1 ON turns ON heater driver 1.

Rear O2 Sensor Heater

Engine Output Controls

Activates the following heated oxygen sensor (HO2S) heater:

HO2S sensor 2

The commanded states include NONE, ON and OFF. Commanding O2S heater driver 2 ON turns ON heater driver 2.