GM Service Manual Online
For 1990-2009 cars only
Table 1: HVAC Control Module Scan Tool Output Controls
Table 2: PCM 3.5L (LX9) / ECM 3.9L (LZ9) Scan Tool Output Controls

HVAC Control Module Scan Tool Output Controls

Scan Tool Output Control

Additional Menu Selection(s)

Description

A/C Request

Output Control

The HVAC control module sends out a A/C request signal to turn on the A/C compressor when you select ON. The request signal should stay active until commanded OFF.

Blower Motor

Output Control

The HVAC control module commands the blower motor Off, Low or High.

Defrost Door

Output Control

The HVAC control module commands the Defrost actuator towards 255 counts when you select ON. The HVAC control module commands the Defrost actuator towards 0 counts when commanded OFF.

Mode Door

Output Control

The HVAC control module commands the Mode actuator towards 255 counts when you select ON. The HVAC control module commands the Mode actuator towards 0 counts when commanded OFF.

Driver Air Temperature Door

Output Control

The HVAC control module commands the left air temperature actuator towards 255 counts when you select ON. The HVAC control module commands the left air temperature actuator towards 0 counts when commanded OFF.

Passenger Air Temperature Door

Output Control

The HVAC control module commands the right air temperature actuator towards 255 counts when you select ON. The HVAC control module commands the right air temperature actuator towards 0 counts when commanded OFF.

Recirculation Door

Output Control

The HVAC control module commands the recirculation actuator towards 0 counts when you select ON. The HVAC control module commands the recirculation actuator towards 255 counts when you select OFF.

Aux. Air Temperature Door

Output Control

The HVAC control module commands the auxiliary air temperature actuator towards 255 counts when you select ON. The HVAC control module commands the auxiliary air temperature actuator towards 0 counts when commanded OFF.

Aux. Mode Door

Output Control

The HVAC control module commands the auxiliary Mode actuator towards 255 counts when you select ON. The HVAC control module commands the auxiliary Mode actuator towards 0 counts when commanded OFF.

Recalibrate Motors

Output Control

The scan tool displays Commanded State: None or On. This functions commands all actuators to their fully opened and fully closed positions, and relearns these endpoints.

Rear Defrost Request

Output Control

The HVAC control module sends out a Rear Defrost Request signal to turn on the Rear Defrost when you select ON.

A/C Switch LED

Output Control

The scan tool displays Commanded State: On or Off. This functions commands the A/C LED On or Off.

Rear Defrost LED

Output Control

The scan tool displays Commanded State: On or Off. This functions commands the Rear Defrost LED On or Off.

All LEDs On

Output Control

The scan tool displays Commanded State: On or Off. This functions commands all LEDs On or Off.

Blower Motor Speed control

Output Control

The scan tool displays Commanded State: Off, On Not Set High or On and Set High.

Aux. Blower Motor Speed

Output Control

This functions commands Auxiliary Blower Motor On or Off.

Driver Heated Seat LED

Output Control

The scan tool displays Commanded State: On or Off. This functions commands the Driver Heated Seat LED On or Off.

Passenger Heated Seat LED

Output Control

The scan tool displays Commanded State: On or Off. This functions commands the Passenger Heated Seat LED On or Off.

Driver Heated Seat Request

Output Control

The scan tool displays Commanded State: High, Low or Off. This functions commands the Driver Heated Seat.

Passenger Heated Seat Request

Output Control

The scan tool displays Commanded State: High, Low or Off. This functions commands the Passenger Heated Seat.

PCM 3.5L (LX9) / ECM 3.9L (LZ9) Scan Tool Output Controls

Scan Tool Output Control

Additional Menu Selection(s)

Description

A/C Relay

Engine Output Controls

The powertrain control module (PCM) or engine control module (ECM) energizes the A/C compressor clutch relay when you select ON. The A/C compressor clutch should remain engaged until commanded OFF.