GM Service Manual Online
For 1990-2009 cars only

Scan Tool Parameter

Data List

Units Displayed

Typical Data Value

Operating Conditions: Ignition ON, Engine OFF

Engine Coolant Temperature Sensor

Cooling/HVAC Data

°C/°F

Varies

Fan Control Relay 1 Command

Cooling/HVAC Data

ON/OFF

OFF

Fan Control Relay 2 and 3 Command

Cooling/HVAC Data

ON/OFF

OFF

Fan Control Relay 1 Circuit Status

Cooling/HVAC Data

OK/Open/Short/Incomplete

Operational

Fan Control Relay 2 and 3 Circuit Status

Cooling/HVAC Data

OK/Open/Short/Incomplete

Operational

5-Volt Reference 1 or 2

Cooling/HVAC Data

V

4.5

5-Volt Reference 1 or 2 Circuit Status

Cooling/HVAC Data

OK/Fault

Operational

Engine Load

Cooling/HVAC Data

0-99%

0-5% - Idle; 3-7% - 2,500 RPM

Calculated Engine Oil Temperature

Cooling/HVAC Data

°C/°F

Varies

Engine Oil Temperature Sensor

Cooling/HVAC Data

°C/°F

Varies

Engine Running Time

Cooling/HVAC Data

0:00:00

Varies

Engine Speed

Cooling/HVAC Data

RPM

650 RPM

Hot Open Loop

Cooling/HVAC Data

Active/Inactive

No Activation

Intake Air Temperature Sensor

Cooling/HVAC Data

°C/°F

Varies

Ignition 1 Signal

Cooling/HVAC Data

0-25.5 V

12.8-14.2 V

Knock Retard

Cooling/HVAC Data

degree

Varies

Spark

Cooling/HVAC Data

°

--

Start Up Engine Coolant Temperature

Cooling/HVAC Data

°C/°F

Varies

Engine Coolant Temperature Calculated Values - Closed Loop Fuel Control

Cooling/HVAC Data

°C/°F

Varies

Engine Coolant Temperature Calculated Values - Thermostat Diagnosis

Cooling/HVAC Data

°C/°F

Varies

Start Up Intake Air Temperature

Cooling/HVAC Data

°C/°F

Varies

Transmission Oil Temperature Sensor

Cooling/HVAC Data

°C/°F

Varies

Total Knock Retard Value

Cooling/HVAC Data

°

0

Vehicle Speed Sensor

Cooling/HVAC Data

km/miles

Varies

Volumetric Efficiency

Cooling/HVAC Data

0-100%

5-2 5% - Idle and at 2,500 RPM