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 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 - 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 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

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 Clutch Feedback Signal

Eng 2

On/Off

Off

A/C High Side Pressure

Eng 2

0-5 volts

Varies

A/C High Side Pressure

Eng 2

kPa/psi

Varies

A/C Relay Command

Eng 1, 2, MF

On/Off

Off

A/C Request Signal

Eng 2

Yes/No

No

AIR Pump Relay Command

Eng 1, FT

On/Off

Off

AIR Solenoid Command

Eng 1, FT

On/Off

Off

Air Fuel Ratio

Eng 2, FF, FR

Ratio

14.7:1

BARO

Eng 1, EE, FT

kPa/volts

65-104 kPa/3.5-4.9 volts (varies w/altitude)

CMP Sensor High to Low

Eng 2

Counts

Varies

CMP Sensor Low to High

Eng 2

Counts

Varies

Clutch Pedal Switch

Eng 1, 2

Depressed/Released

Varies

Cold Startup

Eng 2, EE

Yes/No

Varies

Cruise Control Active

Eng 1

Yes/No

No

Cruise Inhibit Signal

Eng 1

Yes/No

Yes

Current Gear

Eng 1, FT

Transmission Gear Position

1

Cycles of Misfire Data

MF

0-100 Counts

Varies

DTC Set This Ignition

Eng 1, 2, EE, FT

Yes/No

No

Desired IAC Airflow

Eng 1

0-64 g/s

Varies

Desired Idle Speed

Eng 1, 2, EE

RPM

PCM controlled

ECT Sensor

All

-39° to +140°C (-38° to +284°F)

85-113°C (185-235°F)

Engine Load

All

0-100%

1-4% @ Idle

5-9% @ 2500 RPM

Engine Run Time

ALL

Hrs, Min, Sec

Varies

Engine Speed

All

0-10,000 RPM

Varies

EVAP Purge Solenoid Command

Eng 1, EE, FT

0-100%

0-25%

EVAP Vent Solenoid Command

Eng 1, EE, FT

Not Venting/Venting

Venting

Engine Oil Level Switch

ENG 2

--

--

Engine Oil Life Remaining

ENG2

%

--

FC Relay 1 Command

Eng 2

On/Off

Depends on engine coolant temperature and A/C pressure

FC Relay 2 and 3 Command

Eng 2

On/Off

Depends on engine coolant temperature and A/C pressure

Fuel Level Sensor

EE

5-0 volts

0.7-2.5 volts

Fuel Tank Level Remaining

EE

0-16.6 gal/0-62.8 L

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

16.6 gal./62.8 L

16.6 gal/62.8 L

Fuel Trim Cell

Eng 1, FT EE

0-23

16, 17, 20

Fuel Trim Learn

Eng 1, EE, FT

Enabled/Disabled

Enabled, may toggle

Generator L Terminal Signal

Eng 2,

Voltage/No Voltage

Voltage

HO2S Bank 1 Sensor 1

Eng 1, EE, FT

Millivolts

10-1,000 mV 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, EE

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, FT

Counts

Varies

IAT

Eng 1, 2, EE, FT

-39 to +140°C (-38 to +284°F)

Varies

Ignition 1Signal

Eng 1, 2, EE, FT

0-25 volts

11.5-14.5 volts

Inj. PWM Average Bank 1

Eng 2, FT, MF

Milliseconds

1-4

Inj. PWM Average Bank 2

Eng 2, FT, FF, MF

Milliseconds

1-4

Knock Retard

Eng 1

0.0-16°

Long Term FT Average Bank 1

FT

Percentage

Near 0%

Long Term FT Average Bank 2

FT

Percentage

Near 0%

Long Term FT Bank 1

Eng 1, 2, EE,FT

Percentage

Near 0%

Long Term FT Bank 2

Eng 1, 2, EE, FT

Percentage

Near 0%

Loop Status

Eng 1, 2, EE, FT

Open/Closed

Closed

MAF Sensor

All

Grams per second (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

All

kPa/volts

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

Mileage Since DTC Cleared

Eng 2

km/Miles

Varies

Misfire Current #1-#8

MF

0-200 Counts

0

Misfire History #1-#8

MF

0-65,535 Counts

0

MIL Command

ENG 2

ON/OFF

OFF

PCM Reset

Eng 1, 2, EE, FT

Yes/No

No

PCM/VCM in VTD Fail Enable

Eng 1

Enable/Disable

Disable

PNP

Eng 2

Park/Neutral

R-D321

Park/Neutral

Power Enrichment

ENG 2, FT

--

--

Reverse Inhibit Solenoid

Eng 1

Yes/No

No

SHRT FT Average Bank 1

FT

Percentage

Near 0%

SHRT FT Average Bank 2

FT

Percentage

Near 0%

Short Term FT Bank 1

Eng 1, 2, EE, FT

Percentage

Near 0%

Short Term FT Bank 2

Eng 1, 2, EE, FT

Percentage

Near 0%

Skip Shift Lamp (M/T only)

Eng 1

On/Off

Off

Skip Shift Solenoid (M/T only)

Eng 1

Enabled/Disabled

Disabled

Spark

Eng 1, 2, FT, MF

Degrees

Varies

Start Up ECT

Eng 2, EE, FT

C°/F°

Varies

TCC Brake Switch

Eng 1, Eng 2

Applied/Released

Released

TCC PWM Solenoid Command

Eng1, Eng 2, MF

Enabled/Disabled

Disabled

TCC Enable Sol.

Eng 2

Enabled/Disabled

Disabled

TFP SW

Eng 2, FT

39-140°C (38-284°F)

Varies

TP Sensor

All

0-5.0 volts

0.4-0.9 volts

TP Sensor

ALL

%

--

Traction Control Status

Eng 2

Active/Inactive

Inactive

Transmission Range

FT

0-4

1

Vehicle Speed Sensor

All

km/h

mph

0

VTD Auto Learn Timer

Eng 1

Minutes/Seconds

Varies

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