GM Service Manual Online
For 1990-2009 cars only
Table 1: Body Control Module (BCM) Scan Tool Data List
Table 2: Powertrain Control Module (PCM) Scan Tool Data List (LNJ/3.4L)

Use the Scan Tool Data Display Values and Definitions Information in order to assist in diagnosing the HVAC Control Module problems. 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 problem 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).

Body Control Module (BCM) Scan Tool Data List

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

Yes/No

Yes

A/C Sensor

Accessory

Volts

Varies

Battery 1

Accessory

Volts

Varies

Powertrain Control Module (PCM) Scan Tool Data List (LNJ/3.4L)

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 Off for WOT

Engine Data 2

Yes/No

Varies

A/C Off Due to Pressure

Engine Data 2

Active/Inactive

Varies

A/C Pressure Sensor

Engine Data  1,2,3

0 to 5 Volts

Varies

A/C High Side Pressure Sensor

Engine Data  1,2,3

psi/kPa

psi

A/C Relay Command

Engine Data  1,2,3

On/Off

On

A/C Request Signal

Engine Data 2

Yes/No

Yes

ECT

Engine Data 1,2,3

C/F

Varies

Ignition  1 Signal

Engine Data 1,2,3

Volts

Varies