GM Service Manual Online
For 1990-2009 cars only

Scan Tool Data List V8

The Scan Tool Data List contains all engine cooling related parameters that are available on the scan tool. The list is arranged in alphabetical order. A given parameter may appear more than once, or in more than one data list in order to group certain related parameters together.

Use the Scan Tool Data List only after the following is determined:

    • The Diagnostic System Check - Vehicle is completed.
    • No diagnostic trouble codes (DTCs)
    • On-board diagnostics are functioning properly.

Scan tool values from a properly cooling system may be used for comparison with the system you are diagnosing. The Scan Tool Data List represents values that would be seen on a normal cooling system.

Important: A scan tool that displays faulty data should not be used. The scan tool problem should be reported to the manufacturer. Use of a faulty scan tool can result in misdiagnosis and unnecessary parts replacement.

Only the parameters listed below are referenced in this service manual for use in diagnosis. If all values are within the typical range described below, refer to Symptoms - Engine Cooling for diagnosis.

The column labeled Data List indicates where a parameter can be located on the scan tool. Refer to the scan tool operating manual for the exact locations of the data lists. The following is a description of each term listed:

Scan Tool Parameter

Parameter Range/Units

Typical Data Values

Operating Conditions: Engine Idling/Radiator Hose Hot/Closed Throttle/Park/Closed Loop/Accessories OFF

5-Volt Reference 1 Circuit Status

OK/Fault

OK

5-Volt Reference 2 Circuit Status

OK/Fault

OK

5-Volt Reference 1

Volts

4.5 V

5-Volt Reference 2

Volts

4.5 V

Cooling Fan Command

ON/OFF

OFF

Desired Fan Speed

RPM

0

ECT Sensor

-39 to +140°C (-38 to +284°F)

88-105°C (190-221°F)

Engine Load

0-100%

18% @ Idle

21% @ 2500 RPM

Engine Oil Temperature Calculated

Degrees C/F

85-105°C (185-220°F)

Engine Run Time

Hrs, Min, Sec

Varies

Engine Speed

0-10,000 RPM

500-700 RPM

Fan Speed

RPM

0

FC Circuit Status

OK, Incomplete, Short B+, Short Gnd/Open

OK/Incomplete

Fan Relay 1 Command

ON/OFF

OFF

Fan Relay 2 Command

ON/OFF

OFF

Fan Relay 2 and 3 Command

ON/OFF

OFF

Fan Relay 3 Command

ON/OFF

OFF

Hot Open Loop

Active/Inactive

Inactive

IAT Sensor

-39 to +140°C (-38 to +284°F)

35°C (91°F) Depends on Ambient Temperature

Ignition 1 Signal

0-25 Volts

11.5-14.5 Volts

Spark

Degrees

10-17°

Start-Up ECT

°C/°F

Varies

Start-Up IAT

°C/°F

Varies

Total Knock Retard

Degrees

TFT Sensor

°C/°F

Varies

Vehicle Speed Sensor

km/h

mph

0