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 given 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 is determined:

    • A Powertrain On-Board Diagnostic System Check is completed.
    • No Diagnostic Trouble Codes (DTCs).
    • On-board diagnostics are functioning properly.

Scan tool values from a properly running engine may be used for comparison with the engine you are diagnosing. The Engine Scan Tool Data List represents values that would be seen on a normally running engine.

Important: A scan tool that displays faulty data should not be used. The scan tool concern 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 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:

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

Eng 1: Engine Data 1 List

Eng 2: Engine Data 2 List

EE:  Enhanced EVAP Data

FF/FR: Freeze Frame/Failure Records

FT : Fuel Trim Data List

MF: Misfire Data List

Scan Tool Parameter

Data List

Parameter Range/Units

Typical Data Values

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

A/C Compressor Cycling

Eng 1, 2

Closed/Open

Closed/Open

A/C Relay Command

Eng 1, 2, EE, MF

On/Off

Off

A/C Request

Eng 1, 2, EE, MF

Yes/No

No

Air Fuel Ratio

FF, FR

Ratio

14.7:1

BARO

Eng 1, FT, FF, FR

kPa/Volts

65-104 kPa/3.5-4.9 Volts (Varies w/Altitude)

Clutch Switch

Eng1, 2, MF

Depressed/Released

Varies

Cold Startup

Eng1, 2, EE

Yes/No

Varies

Current Gear

Eng 2, FF, FR

Transmission Gear Position

1

Cycles of Misfire Data

MF

0-100 Counts

Varies

Cylinder Mode Misfire Index

MF

Counts

Varies

DTC Set This Ignition

Eng 1, 2, EE, FT, MF

Yes/No

No

Desired IAC Airflow

Eng 1

0-64 g/s

Varies

Desired Idle Speed

Eng 1, FF, FR

RPM

PCM Controlled

ECT

Eng 1, 2, EE, FT, MF, FF, FR

-39° to 140°C (-38° to 284°F)

85° to 113°C (185° to 235°F)

Engine Load

Eng 1, EE, MF, FF, FR

0-100%

1-4% @ Idle

5-9% @ 2500 RPM

Engine Run Time

Eng 1, 2, EE, FF, FR

Hrs, Min, Sec

Varies

Engine Speed

All

0-10,000 RPM

Varies

EVAP Canister Purge

Eng 1, 2, EE, FT, FR

0-100%

0-25%

EVAP Canister Vent Valve

Eng 1, 2, EE, FT

Not Venting/Venting

Venting

Fail Counter

FR

Counts

Varies

Failures Since First Fail

FR

Counts

Varies

FC Relay 1

Eng 1, 2, EE

On/Off

Depends on engine coolant temperature and A/C Pressure

FC Relay 2 and 3

Eng 1, 2, EE

On/Off

Depends on engine coolant temperature and A/C Pressure

FT Diag. Inhibit

FT

Enabled/Disabled

Varies

Fuel Gauge Control

Eng 2, EE

0-100%

Varies

Fuel Level Sensor

Eng 2, EE

5-0 Volts

0.7-2.5 Volts

Fuel Tank Level Remaining

Eng 2, EE, FT

0-19.8 gal./0-75 L

Varies

Fuel Tank Level Remaining

Eng 2, EE, FT

0-100%

Varies

Fuel Tank Pressure

Eng 1, 2, EE

-32.7 to 14.0 mm/Hg (-17.5 to 7.5 in/H2O)

Varies

Fuel Tank Pressure

Eng 2, EE

0-5.0 Volts

Varies

Fuel Tank Rated Capacity

Eng 2, EE, FT

19.8 gal./75 L

19.8 gal./75 L

Fuel Trim Cell

Eng 1, FT

0-23

16, 17, 20

Fuel Trim Learn

Eng 1, 2, EE, FT

Enabled/Disabled

Enabled (may Toggle)

Generator L Terminal

Eng 1, 2

Active/Inactive

Active

HO2S Bank 1 Sensor 1

Eng 1, FT

Millivolts

10-1,000 and Varying

HO2S Bank 1 Sensor 2

Eng 1, FT

Millivolts

10-1,000 mv and Varying

HO2S Bank 2 Sensor 1

Eng 1, FT

Millivolts

10-1,000 mv and Varying

HO2S Bank 2 Sensor 2

Eng 1, FT

Millivolts

10-1,000 mv and Varying

IAC Position

Eng 1

Counts

Varies

IAT

Eng 1, 2, EE, FT

-39° to 140°C (-38° to 284°F)

Varies

Ignition 1

Eng 1, 2, EE

0-25 Volts

11.5-14.5  

Inj. PWM Average Bank 1

Eng 2, EE, FT, FF, FR

Milliseconds

1-4 ms

Inj. PWM Average Bank 2

Eng 2, EE, FT, FF, FR

Milliseconds

1-4 ms

Knock Retard

Eng 1, EE, FT

0 degrees-10degrees

0 degrees

Long Term FT 1 Average

FT

Percentage

Near 0%

Long Term FT 2 Average

FT

Percentage

Near 0%

Long Term FT Bank 1

Eng 1, 2, EE, FT, FF, FR

Percentage

Near 0%

Long Term FT Bank 2

Eng 1, 2, EE, FT, FF, FR

Percentage

Near 0%

Loop Status

Eng 1, 2, EE, FT MF, FF, FR

Open/Closed

Closed

MAF

Eng 1, 2, EE, FT, MF, FF, FR

Grams Per Seconds (g/s)

5-9 g/s @ Idle (depends on altitude)

20-26 g/s @ 2,500 RPM (depends on altitude)

MAF Frequency

Eng 2

0-31,999 Hz

Varies

MAP

Eng 1, 2, EE, FT, FF, FR

kPa/Volts

20-48 kPa/1.0-2.0 V (varies w/altitude)

MIL

Eng 1, 2, EE, FT, MF

Off/On

Off

Mileage Since DTC Cleared

Eng 2

km/Miles

Varies

Mileage Since First Failure

FF, FR

km/Miles

Varies

Mileage Since Last Failure

FR

km/Miles

Varies

Mileage Since MIL Request

FF

km/Miles

Varies

Misfire Current #1-#8

MF

0-200 Counts

0 Counts

Misfire History #1-#8

MF

0-65,535 Counts

0 Counts

Misfiring Cylinder

MF

Prim. Cyl# 0-8

Sec. Cyl# 0-8

00000000 prim.

00000000 sec.

Misfire Revolution Status

MF

Reject/Accept

Varies

Not Run Counter

FR

Counts

Varies

PCM Reset

Eng 1, 2, MF

Yes/No

No

PCM/VCM in VTE Fault

Eng 2

Yes/No

No

Pass Counter

FR

Counts

Varies

Rough Road Sensor

Eng 1, 2, MF

Volts

2.5 V

Revolutions With Misfire

MF

Counts

0 counts

SHRT FT Average 1

FT

Percentage

Near 0%

SHRT FT Average 2

FT

Percentage

Near 0%

Short Term FT Bank 1

Eng 1, 2, EE, FT, FF, FR

Percentage

Near 0%

Short Term FT Bank 2

Eng 1, 2, EE, FT, FF, FR

Percentage

Near 0%

Spark

Eng 1, 2, EE, FT, MF

Degrees

Varies

Start Up ECT

Eng 1, FF, FR, EE

C°/F°

Varies

Total Misfire Current Count

MF

Counts

0 counts

Total Misfire Failures Since First Fail

MF

0-65,535

0

Total Misfire Passes Since First Fail

MF

0-65,535

0

TP Sensor

Eng 1, 2

0-5.0 Volts

0.4-0.9 V

TP Angle

Eng 1, 2, EE, FT, MF, FF, FR

0-100%

0%

VTD Auto Learn Timer

Eng 2, FF, FR

Active/Inactive

Inactive

VTD Fuel Disabled until Ignition Off

Eng 2

Yes/No

No

Vehicle Speed

Eng 1, 2, EE, FT, FF, FR

km/h

mph

0

VTD Fuel Disabled

Eng 1, 2, FF, FR

Active/Inactive

Inactive

Warm-Ups w/o Emission Faults

Eng 2

0-255 Counts

Varies

Warm-Ups w/o Non-Emission Faults

Eng 2

0-255 Counts

Varies