GM Service Manual Online
For 1990-2009 cars only

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

Use the Engine Scan Tool Data List only after the following conditions are determined:

    •  The Diagnostic System Check - Engine Controls is completed.
    •  There are no diagnostic trouble codes (DTCs).
    • The on-board diagnostics are functioning correctly.

Scan tool values from an engine that is operating correctly may be used for comparison with the engine you are diagnosing. The Engine Scan Tool Data List represents the values that would be seen on a normal operating engine.

Important: Do not use a scan tool that displays faulty data. The scan tool concern should be reported to the manufacturer. Use of a faulty scan tool may result in misdiagnosis and unnecessary parts replacement.

Only the parameters listed below are referenced in this service information for use in diagnosis.

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

All: The Parameter is in all data lists indicated below.

Eng 1: Engine Data 1

Eng 2: Engine Data 2

Eng 3: Engine Data 2

O2S/HO2S: Oxygen Sensor Data

Scan Tool Parameter

Data List

Parameter Range/Units

Typical Data Values

Engine Idling/Radiator Hose Hot/Park or Neutral/Closed Loop/Accessories Off

A/C Evap. Temperature Sensor

Eng 2, 3

-40° to +130°C (-40° to +266°F)

Varies

A/C High Side Pressure Sensor

Eng 2

0-5 Volts

Varies

A/C High Side Pressure Sensor

Eng 2, 3

kPa/psi

Varies

A/C Relay Command

Eng 3

On/Off

Off

A/C Request Signal

Eng 3

Yes/No

No

BARO

Eng 2

65-104 kPa

Varies with altitude

Case Diagnostic Learning

Eng 3

Learned/Not Learned

Learned

CASE Learned Cyl. 1

Eng 3

Counts

Varies

CASE Learned Cyl. 2

Eng 3

Counts

Varies

CASE Learned Cyl. 3

Eng 3

Counts

Varies

CASE Learned Cyl. 4

Eng 3

Counts

Varies

Desired Idle Speed

Eng 2

0-8,000 RPM

800 RPM

DTC Set This Ignition

Eng 1

Yes/No

No

ECT Sensor

ALL

-40° to +130°C (-40° to +266°F)

Varies

ECT Sensor

Eng 2

0-5 Volts

Varies

EC Ignition Relay Command

Eng 3

On/Off

On

EGR Position Sensor

Eng 2

0-5 Volts

0.6-0.75 Volts

EGR Solenoid Command

Eng 2, 3

0 - 100%

0%

Engine Load

Eng 1

0-99%

20-30% - Idle

10-20% - 2500 RPM

Engine Speed

ALL

0-8,000 RPM

750-825 RPM

EVAP Purge Solenoid Command (If Equipped)

Eng 2, 3

0-100%

Varies

Fan High

Eng 3

On/Off

Varies

Fan Low

Eng 3

On/Off

Varies

Fuel Gage Control

Eng 3

0-100%

Varies

Fuel Level Sensor

Eng 2

0-5 Volts

Varies

Fuel Level Sensor

Eng 2, 3, HO2S

0-100%

Varies

Fuel Pump Relay Command

Eng 3

On/Off

On

HO2S 1 Heater Command

HO2S

0-100%

Varies

HO2S 2 Heater Command

HO2S

0-100%

Varies

IAT Sensor

Eng 1, 3, HO2S

-39° to +140°C (-38° to +284°F)

Varies

IAT Sensor

Eng 2

0-5 Volts

Varies

Idle Switch

Eng 2

On/Off

On

Ignition 1 Signal

Eng 2, 3, HO2S

Volts

12.0-14.5 Volts

Injector PWM

Eng 2

0-9 ms

4.6-5.4 ms

ISC Command

Eng 2

0 - 100%

Varies

ISC Motor Position Sensor

Eng 2

0 - 100%

Varies

ISC Motor Position Sensor

Eng 2

0-5 Volts

Varies

Knock Sensor

Eng 2

0-5 Volts

Varies

Long Term FT

Eng 1

-50% to +50%

0%

Loop Status

Eng 1, HO2S

Open Loop/Closed Loop

Closed Loop

LT FT Cruise/Accel.

H02S

-50% to +50%

0%

LT FT Idle/Decel

H02S

-50% to +50%

0%

MAP Sensor

Eng 2, 3, HO2S

kPa

32-40 kPa

Varies with Altitude

MIL Command

Eng 1

On/Off

Off

O2S/HO2S 1

Eng 2, HO2S

0-1,006 mV

Varies 400-800 mV

O2S/HO2S 2

Eng 2, HO2S

0-1,006 mV

Varies 400-800 mV

Octane Level

Eng 3

-7 to +7 Counts

Vaires

Short Term FT Avg.

HO2S

-50% to +50%

-3% to +3%

Short Term FT

Eng 1, HO2S

-50% to +50%

-3% to +3%

Spark

Eng 1

-20 to +40 Degrees

2-10 Degrees

TP Sensor

Eng 2

0-5 Volts

4.0-4.5 Volts

TP Sensor

Eng 3, H02S

%

3-5 %

Transmission Gear Selector Signal

Eng 2, 3, H02S

Park/Neutral/In Gear

Park/Neutral

Vehicle Security Status

Eng 3

Enabled/Disabled

Disabled

Vehicle Speed Sensor

All

km/h

mph

0 km/h

(0 mph)