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:

    • The Diagnostic System Check-Engine Controls 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 normal running engine.

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 Controls 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 of the data lists indicated below.

Eng 1: Engine Data 1 List

Eng 2: Engine Data 2 List

EE: Enhanced EVAP Data

FT: Fuel Trim Data List

HO2S: Heated Oxygen Sensor (HO2S) 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

4WD Signal

Eng 2

Enabled/Disabled

Disabled

4WD Low Signal

Eng 2

Enabled/Disabled

Disabled

A/C Compressor Cycling Switch

Eng 2

Open/Closed

Closed

A/C Relay Command

Eng 1, 2, MF

On/Off

Off

A/C Request Signal

Eng 2

Yes/No

No

BARO

Eng 1, EE, FT

kPa/volts

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

Brake Switch

Eng 1, 2

Applied/Released

Released

CMP Retard

Eng 1

Degrees

Minus 9 Degrees

CMP Sensor - Low To High

Eng 2

Counts

Varies

CMP Sensor - High to Low

Eng 2

Counts

Varies

Clutch Pedal Switch

(Manual Transmission only)

Eng 1, 2

Depressed/Released

Released

Cruise Control Active

Eng 1

Yes/No

No

Cruise Inhibit Signal Command

Eng 1

ON/OFF

ON

Current Gear

Eng 1, 2, FT

0-4

1

Cycles of Misfire Data

MF

0-100 Counts

Varies

Decel Fuel Cutoff

HO2S

Active/Inactive

Inactive

Desired IAC Airflow

Eng 1

0-64 g/s

Varies

Desired IAC Position

Eng 1

Counts

Varies

Desired Idle Speed

Eng 1, 2, EE

RPM

PCM Controlled

DTC Set This Ignition

Eng 1, 2, EE, FT, HO2S

Yes/No

No

ECT Sensor

All

-39° to +140°C (-38° to +284°F)

88°C to 105°C (190°F to 221°F) Depends on ambient temperature

Engine Load

All

0-100%

1-4% @ Idle

7-11% @ 2500 RPM

Engine Oil Life Remaining

Eng 2

0-100%

Varies

Engine Oil Pressure Sensor

Eng 2

Volts

0.02 V

Engine Run Time

All

Hrs, Min, Sec

Varies

Engine Speed

All

0-10,000 RPM

500-700 RPM

EVAP Purge Solenoid Command

Eng 1, EE, FT

0-100%

10-25%

EVAP Vent Solenoid Command

Eng 1, EE, FT

Not Venting/Venting

Venting

EVAP Test Result

EE

Test Result

Varies

EVAP Test State

EE

Test State

Varies

Fuel Level Sensor

Eng 1, EE

0-5 volts

0.7-2.5 volts

Fuel Level Sensor Rear Tank, if equipped

EE

Volts

4.94 V

Fuel Tank Level Remaining

EE

Gallon/Liter

Varies

Fuel Tank Level Remaining

EE

0-100%

Varies

Fuel Tank Pressure Sensor

Eng 1, EE

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

Varies

Fuel Tank Pressure Sensor

EE

0-5.0 volts

Varies

Fuel Tank Rated Capacity

EE

98 Liters (25.9 Gallons) or 128 Liters (34 Gallons)

Varies with fuel tank option

Fuel Trim Cell

Eng 1, EE, FT

0-23

16, 17

Fuel Trim Learn

Eng 1, EE, FT

Enabled/Disabled

Enabled (may Toggle)

Gen F Terminal Signal

Eng 2

Percent

Varies

Gen L Terminal Signal Command

Eng 2

ON/OFF

ON

HO2S Bank 1 Sensor 1

Eng 1, EE, FT, HO2S

Millivolts

10-1,000 mV and Varying

HO2S Bank 1 Sensor 2

Eng 1, FT, HO2S

Millivolts

10-1,000 mV and Varying

HO2S Bank 2 Sensor 1

Eng 1, EE, FT, HO2S

Millivolts

10-1,000 mV and Varying

HO2S Heater Bank 1 Sensor 1

HO2S

Amps

0.60 amps

HO2S Heater Bank 1 Sensor 1

HO2S

Amps

0.60 amps

HO2S Heater Bank 1 Sensor 1

HO2S

Amps

0.60 amps

IAC Position

Eng 1, FT

Counts

Varies

IAT Sensor

Eng 1, 2, EE, FT, HO2S

-39° to +140°C (-38° to +284°F)

35°C (91°F) Depends on ambient temperature

Ignition 1 Signal

Eng 1, 2, EE, FT

0-25 volts

11.5-14.5 Volts

Injector PWM Bank 1 Average

Eng 2, FT, MF

Milliseconds

2-6

Injector PWM Bank 2 Average

Eng 2, FT, MF

Milliseconds

2-6

Knock Retard

Eng 1, EGR

0.0°-16°

Long Term FT Avg. Bn 1

FT

Percentage

Near 0%

Long Term FT Avg. Bn 2

FT

Percentage

Near 0%

Long Term FT Bank 1

Eng 1, 2, EE, FT, HO2S

Percentage

Near 0%

Long Term FT Bank 2

Eng 1, 2, EE, FT, HO2S

Percentage

Near 0%

Loop Status

Eng 1, 2, EE, EGR, FT, HO2S

Open/Closed

Closed

MAF Sensor

All

Grams Per Seconds (g/s)

1-9 g/s @ Idle (depends on altitude)

15-26 g/s @ 2,500 RPM (depends on altitude)

MAF Sensor

Eng 2

0-31,999 Hz

2,000-3,000 Hz

MAP Sensor

All

kPa

20-48 kPa

MAP Sensor

Eng 1, 2

Volts

1.0-2.0 volts Varies with altitude

MIL Command

Eng 2

Off/On

Off

Mileage Since DTC Cleared

Eng 2

km/Miles

Varies

Misfire Counter Status

MF

Normal/Invalid

Normal

Misfire Current Cyl. 1-6

MF

0-200 Counts

0

Misfire History Cyl. 1-6

MF

0-65,535 Counts

0

PCM Reset

Eng 1, 2, EE, FT

Yes/No

No

PCM in VTD Fail Enable

Eng 1

Yes/No

No

Power Enrichment

Eng 1, HO2S

Active/Inactive

Inactive

Short Trim FT Avg. Bn 1

FT

Percentage

Near 0%

Short Trim FT Avg. Bn 2

FT

Percentage

Near 0%

Short Term FT Bank 1

Eng 1, 2, EE, FT, HO2S

Percentage

Near 0%

Short Term FT Bank 2

Eng 1, 2, EE, FT, HO2S

Percentage

Near 0%

Spark

Eng 1, 2, FT, HO2S, MF

Degrees

15°-20°

Start Up ECT

Eng 2, EE, FT

C°/F°

Varies

TCC Cruise Brake Pedal Switch

Eng 2

Released/Unreleased

Released

TCC PWM Solenoid Command

Eng 2

ON/OFF

OFF

TCC Enable Solenoid Command

Eng 1, 2, MF

ON/OFF

OFF

Torque Delivered Signal

Eng 2

Ft/Lbs

70-95 ft lbs/varies

Torque Request Signal

Eng 2

Ft/Lbs

2213 Ft Lbs

TP Sensor

All

0-100%

0%

TP Sensor

Eng 1, 2, HO2S

0-5.0 volts

0.4-0.9 volts

TFP SW

Eng 2, FT

Transmission Gear Position

Park/Neutral

TR SW

Eng 2, FT

Transmission Gear Position

Park

Vehicle Speed Sensor

All

km/h

mph

0

VTD Auto Learn Timer

Eng 1

Active/Inactive

Inactive

VTD Fuel Disable

Eng 1

Active/Inactive

Inactive

VTD Fuel Disable Until Ign. Off

Eng 1

Yes/No

No

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