GM Service Manual Online
For 1990-2009 cars only
Table 1: HVAC Control Module Scan Tool Output Controls
Table 2: ECM Scan Tool Output Controls

HVAC Control Module Scan Tool Output Controls

Scan Tool Output Control

Additional Menu Selections

Description

Air Inlet Door Position

HVAC Motors

When you select Outside, the HVAC control module commands the recirculation actuator toward the outside air position. When you select Recirc, the HVAC control module commands the recirculation actuator toward the recirculation position.

Blower Motor

Miscellaneous Test

When you select ON, the HVAC control module commands the blower motor relay ON. When you select OFF, the HVAC control module commands the blower motor relay OFF.

Driver Temp Door Position

HVAC Motors

When you select Cold, the HVAC control module commands the driver air temperature actuator to the full cold position. When you select Hot, the HVAC control module commands the actuator to the full hot position.

Mode Door Position

HVAC Motors

When you select A/C, the HVAC control module commands the mode actuator to the panel position. When you select Defrost, the HVAC control module commands the actuator to the defrost position.

Passenger Temp Door Position

HVAC Motors

When you select Cold, the HVAC control module commands the passenger air temperature actuator to the full cold position. When you select Hot, the HVAC control module commands the actuator to the full hot position.

ECM Scan Tool Output Controls

Scan Tool Output Control

Additional Menu Selections

Description

A/C Relay

Engine Output Controls

The engine must be running and the ECM must receive an A/C request from the HVAC control module in order to enable the output control. The ECM de-energizes the A/C compressor clutch relay when you select OFF. The relay remains de-energized until you select ON.