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 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 Driveability 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

FT: Fuel Trim Data List

CC: Cruise Control Data

TAC: TAC Data List

Engine at Operating Temperature/Engine Idling in Closed Loop/ Closed Throttle/ Park or Neutral/ Acc. OFF

Scan Position

Data List

Units Displayed

Typical Data Value

A/C Status

Eng 2

On/Off

Off

Actual EGR Position

Eng 1

Percentage

0 %

APP Average

Eng 1,

Eng 2,

FT,

CC,

TAC

Counts

Varies

APP Indicated Angle

Eng 1,

Eng 2,

FT,

CC,

TAC

Percentage

Varies

APP Sensor 1

TAC

Volts

0.25-1.1 volts

APP Sensor 2

TAC

Volts

3.9-4.8 volts

APP Sensor 3

TAC

Volts

3.2-4.5 volts

APP Sensor 1 Angle

TAC

Percentage

Varies

APP Sensor 2 Angle

TAC

Percentage

Varies

APP Sensor 3 Angle

TAC

Percentage

Varies

APP Sensor 1 and APP Sensor 2 (Disagree)

TAC

Yes/No

No

APP Sensor 1 and APP Sensor 3 (Disagree)

TAC

Yes/No

No

APP Sensor 2 and APP Sensor 3 (Disagree)

TAC

Yes/No

No

APP Sensor 1 Out of Range

TAC

Yes/No

No

APP Sensor 2 Out of Range

TAC

Yes/No

No

APP Sensor 3 Out of Range

TAC

Yes/No

No

BARO

Eng 1,

FT

kPa

65 - 104 kPa (varies w/Altitude)

BARO

Eng 1,

FT

Volts

3.5-4.5 Volts (varies w/Altitude)

CAM Signal Input - High to Low

Eng 1

Counts

Varies

CAM Signal Input - Low to High

Eng 1

Counts

Varies

CC Brake Switch

Eng 1,

Eng 2,

CC,

TAC

Applied / Released

Released

Clutch Switch

Eng 1

Depressed/ Released

Released

Commanded EGR

Eng 1

Percentage

0 %

Cruise Disengage History 1-8

CC

Refer to Cruise Control Diagnostic Disengage History Table

Varies

Cruise Requested

Eng 1,

CC,

TAC

Yes / No

No

Cruise Resume / Accel

Eng 1,

CC,

TAC

On / Off

Off

Cruise Switch

Eng 1,

CC,

TAC

Off / On

Off

Cruise Set / Coast

Eng 1,

CC,

TAC

On / Off

Off

Desired EGR Position

Eng 1

Percentage

0 %

Desired Idle Speed

Eng 1,

TAC

RPM

PCM Controlled

DTC Set This Ignition

Eng 1,

Eng 2,

FT,

TAC

Yes / No

No

EGR Feedback

Eng 1

Volts

0.65 - 0.80 Volts

EGR Closed Pintle Position

Eng 1

Volts

0.65 - 0.80 Volts

Engine Oil Life Remaining

Eng 2

Percentage

Varies

Engine Oil Pressure

Eng 2

kPa

352-356

Engine Run Time

Eng 1,

Eng 2

Hrs, Min, Sec

Varies

Engine Speed

Eng 1,

Eng 2,

FT,

TAC

RPM

Varies

EOP Sensor

Eng 2

volts

2.10-2.12

ETC

Eng 1,

Eng 2,

FT

°C/°F

Varies

EVAP Canister Purge

Eng 1

Percentage

0 %

Fuel Trim Cell

Eng 1,

FT

0 - 20

Varies

Fuel Trim Diagnostic Inhibit

FT

Enable/Disable

Disable

Fuel Trim Learn

Eng 1,

Eng 2,

FT

Enabled / Disabled

Enabled (may toggle)

HO2S Bank 1 Sensor 1

Eng 1,

FT

Millivolts

10 - 1000 mV and Varying

HO2S Bank 2 Sensor 1

Eng 1,

FT

Millivolts

10 - 1000 mV and Varying

IAT Sensor

Eng 1,

Eng 2,

FT

°C/°F

Varies

Ignition 1

Eng 1,

Eng 2

Volts

0-25 Volts

Injector PWM Average Bank 1

Eng 2,

FT

Milliseconds

1-4

Injector PWM Average Bank 2

Eng 2,

FT

Milliseconds

1-4

Knock Retard

Eng 1,

FT

0.0° - 16°

Varies

Knock Signal Present

Eng 1,

Eng 2

Yes/No

No

Loop Status

Eng 1,

Eng 2,

FT

Open / Closed

Closed

Long Term FT Bank 1

Eng 1,

Eng 2,

FT

Percentage

Varies

Long Term FT Bank 2

Eng 1,

Eng 2,

FT

Percentage

Varies

Long Term FT Bank 1

Eng 1,

Eng 2,

FT

Counts

Varies

Long Term FT Bank 2

Eng 1,

Eng 2,

FT

Counts

Varies

Long Term FT 1 Average

FT

Percentage

Varies

Long Term FT 2 Average

FT

Percentage

Varies

MAF Frequency

Eng 2

0-3199 Hz

Varies

MAF Sensor

Eng 1,

Eng 2,

TAC

Grams Per Seconds (g/s

5-9  g/s (varies w/Altitude)

MAP Sensor

Eng 1,

Eng 2,

TAC

kPa

20 - 48  kPa (varies w/Altitude))

MAP Sensor

Eng 1,

Eng 2,

TAC

Volts

1.0-2.0 Volts (varies w/Altitude)

MIL

Eng 1,

Eng 2

Off / On

Off

Mileage Since DTC Cleared

Eng 2

km/Miles

Varies

PCM Reset

Eng 2

Yes/No

No

Reduced Engine Power

Eng 2,

FT,

CC,

TAC

Active/Inactive

Inactive

Short Term FT Bank 1

Eng 1,

Eng 2,

FT

Counts

Varies

Short Term FT Bank 2

Eng 1,

Eng 2,

FT

Counts

Varies

Short Term FT Bank 1

Eng 1,

Eng 2,

FT

Percentage

Varies

Short Term FT Bank 2

Eng 1,

Eng 2,

FT

Percentage

Varies

Short Term FT 1 Average

Eng 1,

Eng 2,

FT

Percentage

Varies

Short Term FT 2 Average

Eng 1,

Eng 2,

FT

Percentage

Varies

Spark

Eng 1,

Eng 2,

FT

Degrees

Varies

Startup ETC

Eng 1

°C/°F

Varies

TAC/PCM Communication

Eng 1,

CC,

TAC

Ok/Fault

Ok

TP Desired Angle

Eng 1,

Eng 2,

FT,

CC,

TAC

Percentage

3 - 10 %

TP Indicated Angle

Eng 1,

Eng 2,

FT,

CC,

TAC

Percentage

3 - 9 %

TP Sensors Disagree

TAC

Yes/No

No

TP Sensor 1 Out of Range

TAC

Yes/No

No

TP Sensor 2 Out of Range

TAC

Yes/No

No

TP Sensor 1

TAC

Volts

0.25-1.5 volts

TP Sensor 2

TAC

Volts

3.0-1.5 volts

Vehicle Speed

Eng 1,

Eng 2,

FT,

CC,

TAC

km/h/mph

Varies

Warn-Ups w/o Emission Faults

Eng 2

Counts

Varies

Warm-Ups w/o Non-Emission Faults

Eng 2

Counts

Varies