Scan Tool Output Controls. Chevrolet Blazer

For 1990-2009 cars only

Makes 🢒 Chevrolet 🢒 2003 🢒 Blazer - 2WD 🢒 Engine 🢒 Engine Controls - 4.3L 🢒 Scan Tool Output Controls

Scan Tool Output Control

Additional Menu Selection(s)

Description

Crankshaft Position Variation Learn

Enables the powertrain control module (PCM) to learn the variations in the crankshaft position (CKP) system. The PCM will learn the variations once the following conditions are met:

•	Engine coolant temperature (ECT) is more than a specified value.

•	All instructions on the scan tool have been completed.

•	The accelerator pedal is smoothly applied until the fuel cut-OFF, as specified on the scan tool, is achieved, and then immediately released.

The PCM learns the variation values on the deceleration from fuel cut-OFF.

Cylinder Power Balance

Fuel System

Enables/Disables a cylinder by turning OFF the fuel injector to the cylinder. The fuel injector is normally enabled. The PCM disables the fuel injector when the following conditions are met:

•	All instruction on the scan tool are completed

•	Stabilized engine speed

•	The fuel injector is selected

When the Disable is selected the PCM turns the injector OFF for 30 seconds. During this period, the engine operates with a misfire.

RPM Control

IAC System

Activates the idle air control (IAC) valve to change engine RPM. The normal commanded state is NONE. To enable the RPM control, all instruction on the scan tool must be completed. The system will INCREASE or DECREASE the RPM within a range of 400-2,000 RPM. The SET STEP VALUE changes the RPM by increments of 25 RPM, 100-500 RPM. The system remains in the commanded state until cancelled by the tool.

EVAP Purge Solenoid

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 0-100 percent. The system remains in the commanded state until cancelled by the tool or the fuel tank pressure (FTP) exceeds 32 mm Hg (17 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, non-venting. The normal commanded state of both valves 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 second function seals the system after using the purge function to obtain a specific amount of FTP. When activated the purge valve is commanded to 0 percent and the vent valve is commanded ON, non-venting. Both functions remain in the commanded state until one of the following conditions occurs:

•	Cancelled by the tool

•	The FTP exceeds 32 mm Hg (17 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 until one of the following conditions occurs:

•	Cancelled by the tool

•	Purge is greater than 0 percent, and the fuel tank pressure exceeds 32 mm Hg (17 in H20)

Fuel Injector Balance

Fuel System

Enables the fuel injector in order to verify proper fuel injector flow. The PCM will pulse the selected injector when the following conditions are met:

•	All instruction on the scan tool completed

•	Fuel injector selected

•	Key ON, engine OFF

The selected fuel injector can only be flowed/pulsed once per ignition cycle.

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.

Fuel Trim Enable

Fuel System

Disables the PCMs ability to learn new fuel trim parameters. The system remains in the commanded state until cancelled by the scan tool.

Fuel Trim Reset

Fuel System

Activates the reset of fuel trim data in all of the fuel trim cells.

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.

Misfire Graph

Graphs the accumulated misfires occurring in each cylinder. The scan tool allows for a reset of the misfire graph.

O2S Heater Control

Engine Output Controls

Activates the HO2S Heater. The commanded states include None, ON, and OFF. The normal commanded state is None. On a cold engine, with the key ON, engine OFF, the HO2S signal will continue to drop below bias when commanded ON. The system remains in the commanded state until cancelled by the tool.