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

HVAC Control Module Scan Tool Output Controls

Scan Tool Output Control

Additional Menu Selection(s)

Description

A/C LED

Miscellaneous Test

The HVAC control module illuminates the A/C indicator LED when you select ON. The LED should remain illuminated until commanded OFF.

A/C Request

Miscellaneous Test

The HVAC control module sends an A/C request signal to the PCM when you select ON. The PCM should energize the A/C compressor clutch relay. The A/C compressor clutch relay should remain energized until commanded OFF.

Blower Motor

Miscellaneous Test

The HVAC control module commands the blower motor on to maximum speed when you select ON. The blower motor should operate at maximum speed until commanded OFF.

Mix Motor

Miscellaneous Test

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

Select Solenoid 1

Solenoid Test

The HVAC control module energizes the defroster solenoid when you select ON. The solenoid should remain energized until commanded OFF. Blower motor operation is disabled during this test.

Select Solenoid 2

Solenoid Test

The HVAC control module energizes the heater solenoid when you select ON. The solenoid should remain energized until commanded OFF. Blower motor operation is disabled during this test.

Select Solenoid 3

Solenoid Test

The HVAC control module energizes the solenoid when you select ON. The solenoid should remain energized until commanded OFF. Blower motor operation is disabled during this test.

Select Solenoid 4

Solenoid Test

The HVAC control module energizes the air inlet solenoid when you select ON. The solenoid should remain energized until commanded OFF. Blower motor operation is disabled during this test.

Select Solenoid 5

Solenoid Test

The HVAC control module energizes the A/C solenoid when you select ON. The solenoid should remain energized until commanded OFF. Blower motor operation is disabled during this test.

PCM Scan Tool Output Controls

Scan Tool Output Control

Additional Menu Selection(s)

Description

A/C Relay

Engine Output Controls

The PCM energizes the A/C compressor clutch relay when you select ON. The A/C compressor clutch should remain engaged until commanded OFF.