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 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 conditions are determined:

    •  The Diagnostic System Check-Engine Controls is completed.
    •  There are no diagnostic trouble codes (DTCs).
    • The 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 the values that would be seen on a normal running engine.

Important: Do not use a scan tool that displays faulty data. The scan tool concern should be reported to the manufacturer. Use of a faulty scan tool can result in misdiagnosis and in 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 .

The column labeled Data List indicates where a parameter is located on the scan tool. Review 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.

Input: General Info-Inputs

Output: General Info-Outputs

FE: Fuel and Emissions

Ign: Ignition

MF: Misfire

Aux: Auxiliary Emissions

Idle: Idle/Speed Control

Eng: Engineering

FF: Freeze Frame Data List

FR: Failure Record Data List

Scan Tool Parameter

Data List

Units Displayed

Typical Data Value

Engine Idling/Upper Radiator Hose Hot/Closed Throttle/Transmission in Park or Neutral/Closed Loop

AC High Side Pressure

Input

kPa

Varies

AC Pressure Sensor

Input

Volts

Varies

AC Relay Command

Input, Output, Idle

On/Off

Off

AC Request

Input, Idle

Yes/No

No

Air Fuel Ratio

FE

XX :1

14.7:1

APP Angle

All

Percent

0%

APP at Idle

Idle

Yes/No

Yes

APP Sensor 1

Input, FE, Idle

Volts

0.9-1.0 Volts

APP Sensor 2

Input, FE, Idle

Volts

0.4-0.6 Volts

BARO

Input, FE

kPa

95-101 kPa

Brake Switch

Input, Idle

Applied/Released

Released

Calculated Converter Temperature

Eng

°C (°F)

Varies, typical 400-532°C (750-990°F)

Crankshaft Position Sensor A

Input

Counts

0-3 Counts

Crankshaft Position Sensor B

Input

Counts

0 Counts

Cruise Brake Switch

Input, Idle

Applied/Released

Released

Cruise Engaged

Input, Idle

Yes/No

No

Cruise Resume/Accelerate

Input, Idle

On/Off

Off

Cruise Set/Coast

Input, Idle

On/Off

Off

Cruise Switch

Input, Idle

On/Off

Off

Decel Fuel Cutoff

FE

Active/Inactive

Inactive

Desired Idle Speed

Idle

RPM

700 RPM

ECT Sensor

All

°C (°F)

80-90°C (176-194°F)

Engine at Operating Temperature

FE

Yes/No

Yes

Engine Load

All

Percent

9-30%

Engine Run Time

All

Hours/Minutes/Seconds

Varies

Engine Oil Life Left

Input

Percent

Varies

Engine Speed

All

RPM

700-800 RPM

EVAP Purge Solenoid DC

Output, FE, Aux

Percent

Varies

EVAP Vent Solenoid

Output, Aux

On/Off

Off

EGR Duty Cycle

Input, Output, Aux

Percent

0 %

EGR Sensor

Input, Aux

Volts

1.17 Volts

Fan Control 1 Command

Output

On/Off

Varies

Fan Control 2 Command

Output

On/Off

Varies

Fuel Level

Input, FE, Ign, MF

Liters/Gallons

Varies

Fuel Level Sensor

Input, FE, Ign, Aux

Volts

Varies

Fuel Level

FE, Ign, MF, Aux

Percent

Varies

Fuel Pump Relay Command

Output

On/Off

On

Fuel Tank Pressure Sensor

Input

Volts

Varies

Fuel Tank Pressure Sensor

Input, FE

mmHg (inH2O)

Varies

Generator F Terminal

Input

Percent

Varies

Generator LTerminal

Input

Active/Inactive

Inactive

HO2S Bank 1 Sensor 1

Input, FE

Lambda

Varies, 0.998-1.002 Lambda typical

HO2S Bank 1 Sensor 2

Input, FE

mV

Varies

HO2S Bank 2 Sensor 1

Input, FE

Lambda

Varies, 0.998-1.002 Lambda typical

HO2S Bank 2 Sensor 2

Input, FE

mV

Varies

HO2S Heater Bank 1 Sensor 1

Output, FE

On/Off

On

HO2S Heater Bank 1 Sensor 2

Output, FE

On/Off

Varies

HO2S Heater Bank 2 Sensor 1

Output, FE

On/Off

On

HO2S Heater Bank 2 Sensor 2

Output, FE

On/Off

Varies

Idle Increase Command (AC Request Only)

Idle

Yes/No

No

Ignition 1

All

Volts

10-14 Volts

Injector PWM Bank 1

FE

ms

2.4-2.8 ms

Injector PWM Bank 2

FE

ms

2.4-2.8 ms

IAT Sensor 1

Input, Aux

°C (°F)

Varies with underhood and ambient air temperatures

IAT Sensor 2

Input, FE, Ign, MF, Aux, Eng, Idle

°C (°F)

Varies with underhood and ambient air temperatures

Intake Rocker Arm Actuator Solenoid Command

Output

On/Off

Off

Intake Rocker Arm Actuator Oil Pressure Switch

Input, Output

On/Off

Off

Knock Sensor

Input, Output

Volts

0.0 Volts

Knock Control

Input, Output

Active/Inactive

Inactive

Long Term FT Bank 1

FE, Aux, FF, FR

Percent

-10% to +10%

Long Term FT Bank 2

FE, Aux, FF, FR

Percent

-10% to +10%

Loop Status Bank 1

FE, Eng, FF, FR

Open/Closed

Closed Loop

Loop Status Bank 2

FE, Eng, FF, FR

Open/Closed

Closed Loop

Low Oil Pressure Switch

Input

Open/Closed

Closed

Main Relay

Output

On/Off

On

MAP Sensor

Input

Volts

1.0-2.0 volts (varies w/ altitude)

MAP Sensor

Input, FE, Ign, MF, Aux, Eng, Idle, FF, FR

kPa

20-40 kPa (varies w/ altitude)

Misfire Current Cyl #1

MF

Counts

0 Counts

Misfire Current Cyl #2

MF

Counts

0 Counts

Misfire Current Cyl #3

MF

Counts

0 Counts

Misfire Current Cyl #4

MF

Counts

0 Counts

Misfire Current Cyl #5

MF

Counts

0 Counts

Misfire Current Cyl #6

MF

Counts

0 Counts

Misfire History Cyl #1

MF

Counts

0 Counts

Misfire History Cyl #2

MF

Counts

0 Counts

Misfire History Cyl #3

MF

Counts

0 Counts

Misfire History Cyl #4

MF

Counts

0 Counts

Misfire History Cyl #5

MF

Counts

0 Counts

Misfire History Cyl #6

MF

Counts

0 Counts

Power Enrichment

FE

Yes/No

No

Rough Road Detection

MF

Present/Not Present

Not Present

Short Term FT Bank 1

FE, Aux, FF, FR

Percent

-10% to +10%

Short Term FT Bank 2

FE, Aux, FF, FR

Percent

-10% to +10%

Spark Advance

Ign, FF, FR

Degrees

9° to 12°

Start Up ECT

FE

Degrees

Varies

TAC Limit Engine Power

Eng

Yes/No

No

TAC Module Power Inhibit Feedback

Output

Volts

0.67 Volts

Throttle Plate at Idle

Idle

Yes/No

Yes

Throttle Plate at WOT

Idle

Yes/No

No

TP Angle

All

Percent

9-14%

TPS Learned Value

FE, Idle

Percent

Varies

Vehicle Speed

All

km/h/mph

0 km/h / 0 mph