GM Service Manual Online
For 1990-2009 cars only
Table 1: PCM
Table 2: BCM

Use the Scan Tool Data Display Values and Definitions in order to assist in diagnosing the HVAC. Compare the vehicles actual scan tool data with the typical data display value table information. Use the data information in order to aid in understanding the nature of the concern when the vehicle does not match with the typical data display values.

The scan tool data values were taken from a known good vehicle under the following conditions:

    • The ignition switch is in the ON position.
    • The engine is running at idle.
    • The vehicle is in PARK.
    • The doors are closed.
    • The windows are closed.
    • The A/C is ON.
    • The ambient air temperatures are at 22-27°C (70-80°F).

PCM

Scan Tool Parameter

Data List

Units Displayed

Typical Data Value

Operating Conditions: Engine idling, A/C ON, ambient air temperature between 22-27°C (70-80°F)

A/C Disengage Reason

Engine Data

None, System Voltage, WOT, CKP Learn Active, Engine Run Time, Coolant Hot, Anti Stall, A/C Pressure, Engine Speed, Trans Engine Spd, A/C Press Sensor, Low Voltage, High Voltage, Outside Air Temp, A/C Switched Off

None

A/C Pressure Disable

Engine Data

Yes/No

No

A/C High Side Pressure Sensor LX9/3.5L only

Engine Data

kPa/psi

Varies

A/C High Side Pressure Sensor LX9/3.5L only

Engine Data

Volts

Varies

A/C Off for WOT

Engine Data

Yes/No

Varies

A/C Relay Circuit History

Engine Data

OK/Open/Short

OK

A/C Relay Circuit Status

Engine Data

OK/Fault

OK

A/C Relay Command

Engine Data

Yes/No

Varies

A/C Request Signal

Engine Data

Yes/No

Varies

FC Relay 1 Command LX9/3.5L only

Engine Data

On/Off

Varies

FC Relay 2 and 3 Command LX9/3.5L only

Engine Data

On/Off

Varies

ECT Sensor

Engine Data

°C/°F

Varies

Ignition 1 Signal

Engine Data

Volts

Varies

BCM

Scan Tool Parameter

Data List

Units Displayed

Typical Data Value

Operating Conditions: Engine idling, A/C ON, ambient air temperature between 22-27°C (70-80°F)

A/C Request Switch

Inputs

On/Off

Varies

Outside Air Temp. Sensor

Inputs

Volts

Varies