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:

    • 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 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 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

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

Scan Tool Parameter

Vehicle Platform

Data List

Parameter Range/Units

Typical Data Values

4WD

K

Eng 2

Enabled/Disabled

Disabled

4WD Low

K

Eng 2

Enabled/Disabled

Disabled

A/C Relay Command

C, K

Eng 1, 2, EE, MF

On/Off

Off

A/C Compressor Cycling Switch

C, K

Eng 2

Open/Closed

Closed

Actual EGR Position

C, K

Eng 1, FF, FR

0-100%

0%

A/C Request

C, K

Eng 1, 2, EE, MF

Yes/No

No

A/C Sec. High Pressure Switch

C, K

Eng 2

Open/Closed

Open

Air Fuel Ratio

C, K

FF, FR

Ratio

14.7:1

AIR Pump Relay

(w/NC1)

C, K

Eng 1, 2, FT

On/Off

Off

BARO

C, K

Eng 1, FT, FF, FR

kPa/Volts

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

Brake Switch

C, K

Eng 1, 2, MF, FF, FR

Applied/Released

Released

CAM Signal Input High to Low

C, K

Eng 1

Counts

Varies

CAM Signal Input Low to High

C, K

Eng 1

Counts

Varies

Clutch Pedal Position Switch

(Manual Transmission only)

C, K

Eng 1, 2

Depressed/Released

Released

Cold Startup

C, K

Eng1, 2

Yes/No

Varies

Commanded EGR

C, K

Eng1

0-5 Volts

Less than 1.3 volts

Cruise Engaged

C, K

Eng 2

Yes/No

No

Current Gear

C, K

Eng 2, FF, FR

0-4

1

Cycles of Misfire Data

C, K

MF

0-100 Counts

Varies

Cyl. Mode Misfire Index

C, K

MF

Counts

Varies

Desired EGR Position

C, K

Eng 1, FF, FR

0-100%

0%

Desired IAC Airflow

C, K

Eng 1

0-64 g/s

Varies

Desired IAC Position

C, K

Eng 1

Counts

Varies

Desired Idle Speed

C, K

Eng 1, FF, FR

RPM

PCM Controlled

DTC Set This Ignition

C, K

Eng 1, 2, EE, FT

Yes/No

No

ECT

C, K

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

-39° to 140°C (-38° to 284°F)

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

EGR Closed Pintle Position

C, K

Eng 1

0-5.0 Volts

Less than 1.3 Volts

EGR Pintle Position

C, K

Eng 1, FF, FR

0-5.0 Volts

Less than 1.3 Volts

Engine Load

C, K

Eng 1, MF, FF, FR

0-100%

1-4% @ Idle

7-9% @ 2500 RPM

Engine Oil Life Remaining

C, K

Eng 2

0-100%

Varies

Engine Run Time

C, K

Eng 1, 2, EE, FF, FR

Hrs, Min, Sec

Varies

Engine Speed

C, K

All

0-10,000 RPM

500-700 RPM

EVAP Canister Purge

C, K

Eng 1, 2, EE, FT

0-100%

10-25%

EVAP Canister Vent Valve

C, K

Eng 1, 2, EE, FT

Not Venting/Venting

Venting

EVAP Test Inhibited

C, K

EE

Yes/No

Varies

EVAP Test Result

C, K

EE

Test Result

Varies

EVAP Test State

C, K

EE

Test State

Varies

Fail Counter

C, K

FF, FR

Counts

Varies

FT Diag. Inhibit

C, K

FT

Enabled/Disabled

Varies

Fuel Level Sensor

C, K

Eng 2, EE

5-0 Volts

0.7-2.5 volts

Fuel Slosh Detected

C, K

EE

Yes/No

No

Fuel Tank Level Remaining

C, K

Eng 2, EE, FT

Gallon/Liter

Varies

Fuel Tank Level Remaining

C, K

Eng 2, EE, FT

0-100%

Varies

Fuel Tank Pressure

C, K

Eng 1, 2, EE

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

Varies

Fuel Tank Pressure

C, K

Eng 1, 2, EE

0-5.0 Volts

Varies

Fuel Tank Rated Capacity

C, K

Eng 2, EE, FT

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

Varies with fuel tank option

Fuel Trim Cell

C, K

Eng 1, FT

0-23

16, 17

Fuel Trim Learn

C, K

Eng 1, 2, EE, FT

Enabled/Disabled

Enabled (may Toggle)

Generator L Terminal

C, K

Eng 1, 2

Active/Inactive

Active

HO2S Bank 1 Sensor 1

C, K

Eng 1, FT

Millivolts

10-1,000 mV and Varying

HO2S Bank 1 Sensor 2

C, K

Eng 1, FT

Millivolts

10-1,000 mV and Varying

HO2S Bank 2 Sensor 1

C, K

Eng 1, FT

Millivolts

10-1,000 mV and Varying

HO2S Bank 2 Sensor 2

C, K

Eng 1, FT

Millivolts

10-1,000 mV and Varying

HVAC in Recirculation Mode

C, K

Eng 2

Yes/No

No

IAC Position

C, K

Eng 1

Counts

Varies

IAT

C, K

Eng 1, 2, EE, FT

-39° to 140°C (-38° to 284°F)

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

IC Circuit Cylinder 1-8

C, K

MF

Ok/Fault

Ok

Ignition 1

C, K

Eng 1, 2, EE

0-25 Volts

11.5-14.5 Volts

Inj. PWM Average Bank 1

C, K

Eng 2, EE, FT, FF, FR

Milliseconds

2-6

Inj. PWM Average Bank 2

C, K

Eng 2, EE, FT, FF, FR

Milliseconds

2-6

Knock Retard

C, K

Eng 1, FT

0.0°-16°

Long FT 1 Average

C, K

FT

Percentage

Near 0%

Long FT 2 Average

C, K

FT

Percentage

Near 0%

Long Term FT Bank 1

C, K

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

Percentage

Near 0%

Long Term FT Bank 2

C, K

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

Percentage

Near 0%

Loop Status

C, K

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

Open/Closed

Closed

Low Coolant Level

C, K

Eng 1, 2

Yes/No

No

Low Oil Lamp

C, K

Eng 1, 2

On/Off

Off

Low Oil Level

C, K

Eng 1, 2

Yes/No

No

MAF

C, K

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

Grams Per Seconds (g/s)

1-9 g/s @ Idle (depends on altitude)

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

MAF Frequency

C, K

Eng 1, 2

0-31,999 Hz

2,000-3,000 Hz

MAP

C, K

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

kPa/Volts

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

MIL

C, K

Eng 1, 2, EE

Off/On

Off

Mileage Since DTC Cleared

C, K

Eng 2

km/Miles

Varies

Mileage Since First Failure

C, K

FF, FR

km/Miles

0

Mileage Since MIL Request

C, K

FF, FR

km/Miles

0

Misfire Current Cyl. 1-8

C, K

MF

0-200 Counts

0

Misfire History Cyl. 1-8

C, K

MF

0-65,535 Counts

0

Misfiring Cylinder

C, K

MF

Prim. Cyl# 0-8

Sec. Cyl# 0-8

00000000 Prim.

00000000 Sec.

Misfire Revolution Status

C, K

MF

Reject/Accept

Accept

Not Run Counter

C, K

FF, FR

Counts

Varies

Pass Counter

C, K

FF, FR

Counts

Varies

PCM Reset

C, K

Eng 1, MF

Yes/No

No

PCM/VCM in VTD Fail Enable

C, K

Eng 1

Yes/No

No

PRND A Input

C, K

Eng 2

On/Off

On

PRND B Input

C, K

Eng 2

On/Off

Off

PRND C Input

C, K

Eng 2

On/Off

Off

PRND P Input

C, K

Eng 2

On/Off

On

PRND Position

C, K

Eng 2

Transmission Gear Position

Park

Revolutions With Misfire

C, K

MF

Counts

0

SHRT FT 1 Average

C, K

FT

Percentage

Near 0%

SHRT FT 2 Average

C, K

FT

Percentage

Near 0%

Short Term FT Bank 1

C, K

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

Percentage

Near 0%

Short Term FT Bank 2

C, K

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

Percentage

Near 0%

Spark

C, K

Eng 1, 2, EE, FT, MF

Degrees

15°-20°

Start Up ECT

C, K

Eng 1, EE, FF, FR

C°/F°

Varies

TCC Duty Cycle

C, K

Eng 1, 2, MF, FF, FR

Percentage

0%

TCC Enable Solenoid

C, K

Eng 1, 2, MF, FF, FR

Enabled/Disabled

Disabled

Total Misfire Current Count

C, K

MF

Counts

0

Total Misfire Failures Since First Fail

C, K

MF

0-65,535

0

Total Misfire Passes Since First Fail

C, K

MF

0-65,535

0

TP Angle

C, K

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

0-100%

0%

TP Sensor

C, K

Eng 1, 2

0-5.0 Volts

.4-.9 Volts

Transmission OSS

C, K

FF, FR

RPM

0 RPM

Transmission Range

C, K

Eng 1, 2, FF, FR

Transmission Gear Position

Park/Neutral

Vehicle Speed

C, K

ENG 1, 2, EE, FT, FF, FR

km/h

mph

0

VTD Auto Learn Timer

C, K

Eng 1, FF, FR

Active/Inactive

Inactive

VTD Fuel Disable

C, K

Eng 1

Active/Inactive

Inactive

VTD Fuel Disable Until Ign. Off

C, K

Eng 1

Yes/No

No

Warm-Ups w/o Emission Faults

C, K

Eng 2

0-255 Counts

Varies

Warm-Ups w/o Non-Emission Faults

C, K

Eng 2

0-255 Counts

Varies