A/C Relay

Special Functions/Engine Output Controls

Important: This function is only allowed with the ignition ON, engine OFF.

This function controls the A/C compressor relay. When commanded ON, the A/C compressor will cycle ON/OFF for 3-5 seconds.

EGR Solenoid

Special Functions/Engine Output Controls

Important: This function is only allowed with the ignition ON, engine OFF.

This function controls the exhaust gas recirculation (EGR) solenoid. The EGR solenoid will cycle from 0-100 percent for 3-5 seconds several times, when commanded ON. This output can also be monitored on the scan tool by observing the EGR Position Sensor data parameter.

Engine Controls Ignition Relay

Special Functions/Engine Output Controls

Important: This function is only allowed with the ignition ON, engine OFF, and there are no DTCs set.

This function controls the engine controls ignition relay or MAIN relay. The relay is always ON when the ignition is ON or the engine is running. When commanded OFF, the engine controls ignition relay will turn OFF for 3-5 seconds. Commanding the relay OFF will set some DTCs, which must be cleared before the relay can be commanded OFF again.

EVAP Purge Solenoid

Special Functions/Engine Output Controls/EVAP System

Important: This function is only allowed with the ignition ON, engine OFF.

This function controls the EVAP purge solenoid. The EVAP purge solenoid will cycle ON between 5 percent and 95 percent several times, when commanded ON. This output can be monitored on the scan tool by observing the EVAP Purge Solenoid Command data parameter.

EVAP Vent Solenoid

Special Functions/Engine Output Controls/EVAP System

Important: This function is only allowed with the ignition ON, engine OFF.

This function controls the EVAP vent solenoid. The EVAP vent solenoid will cycle ON/OFF for 1-2 seconds several times, when commanded ON. This output can be monitored on the scan tool by observing the EVAP Vent Solenoid Command data parameter.

Fan High

Special functions/Engine Output Controls/Fan Controls

Important: This function is only allowed with the ignition ON, engine OFF.

This function controls the high speed cooling fan relay. When commanded ON, the cooling fan will turn ON at high speed for 5 seconds.

Fan Low

Special functions/Engine Output Controls/Fan Controls

Important: This function is only allowed with the ignition ON, engine OFF.

This function controls the low speed cooling fan relay. When commanded ON, the cooling fan will turn ON at low speed for 5 seconds.

Fuel Pump Relay

Special Functions/Engine Output Controls

Important: This function is only allowed with the ignition ON, engine OFF.

This function controls the fuel pump relay. When commanded ON, the fuel pump relay will cycle ON/OFF for 3-5 seconds.

Idle Learn Reset, w/o TAC only

Special Functions/Engine Output Controls/Reset Learned Values

This function resets the base idle value learned by the ECM.

ISC Actuator, w/o TAC only

Special Functions/Engine Output Controls

Important: This function is only allowed with the ignition ON, engine OFF.

This function controls the idle speed control (ISC) actuator. The ECM actuates the ISC actuator for 3-5 seconds when commanded ON. This output can also be monitored on the scan tool by observing the TP Sensor data parameter.

ISC System, w/o TAC only

Special Functions/Engine Output Controls/Reset Learned Values

This function resets the learned values for the Idle Speed Control (ISC) system in the ECM

Injector 1-6

Special Functions/Engine Output Controls

This function controls the selected fuel injector while the engine is running. When commanded ON, the selected fuel injector will be turned OFF for 5 seconds. This output can also be monitored by observing the appropriate fuel control HO2S. The HO2S voltage should indicate lean, low voltage, when the fuel injector is turned OFF.

IMT Valve

Special Functions/Engine Output Controls

Important: 

This function controls the intake manifold tuning (IMT) valve solenoid. The IMT valve solenoid will cycle ON/OFF for 3-5 seconds several times, when commanded ON. This output can also be monitored by observing the IMT valve actuator move as the solenoid allows vacuum to it.

Malfunction Indicator Lamp

Special Functions/Engine Output Controls

This function controls the malfunction indicator lamp (MIL). When commanded ON, the ECM flashes the MIL ON/OFF for 5 seconds.

Reset ECM

Special Functions/Engine Output Controls/Reset Learned Values

This function resets the all values learned by the ECM.

TAC Motor Command, with TAC only

Special Functions/Engine Output Controls

Important: This function is only allowed with the ignition ON, engine OFF.

This function controls the Throttle Actuator Control (TAC) motor. The ECM actuates the TAC motor to move the throttle plate from closed to open, for 3-5 seconds several times, when commanded ON. This output can be monitored on the scan tool by observing the TP Sensors and TAC Motor Command data parameters.

TAC System

Special Functions/Engine Output Controls/Reset Learned Values

This function resets the learned values for the Throttle Actuator Control (TAC) system in the ECM.