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 correctly.

Scan tool values from an engine that is operating correctly 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 operating 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 may result in misdiagnosis and unnecessary parts replacement.

Only the parameters listed below are referenced in this service information 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 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.

Eng: Engine Data

EGR: EGR Data

EVAP: EVAP Data

FT: Fuel Trim Data

HO2S: O2S/HO2S Data

MF: Misfire Data

CH: Cooling/HVAC Data

IPC: IPC Data

FF: Freeze Frame Data

FR: Failure Records Data

Scan Tool Data List

Scan Tool Parameter

Data List

Parameter Range/Units

Typical Data Values

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

5 Volt Reference 1

EGR, EVAP, CH

0-5 Volts

5.0 Volts

A/C High Side Pressure Sensor

CH

0-5 Volts

Varies

A/C High Side Pressure Sensor

CH

kPa/psi

Varies

A/C Relay Command

Eng, EGR, MF, CH

On/Off

Off

A/C Request Signal

CH

Yes/No

No

Air Flow Calculated

Eng , FT, HO2S, MF, FF, FR

g/s

3-6 g/s

Air Fuel Ratio

Eng, FT, HO2S, FF, FR

Ratio

14.7:1

BARO

Eng , EGR, EVAP, HO2S, FT, FF, FR, MF

65-104 kPa

Varies with altitude

Catalytic Converter Protection Active

HO2S, FT, MF

Yes/No

No

CMP Active Counter

Eng, MF

1-3 Counts

Varies

Coolant Hot Lamp (If Equipped)

IPC

On/Off

Off

Decel. Fuel Cutoff

EGR, FT, HO2S

Active/Inactive

Inactive

Desired EGR Position

EGR

%

Varies

Desired IAC Position

Eng

Counts

Varies

Desired Idle Speed

Eng, EVAP, FF, FR

0-7,000 RPM

800-950 RPM

ECT Sensor

Eng , EGR, EVAP, FT, HO2S, MF, CH, IPC, FF, FR

-39°C to +140°C (-38°F to +284°F)

Varies

EGR Flow Test Count

EGR

Counts

Varies

EGR Learned Minimum

EGR

Volts

Varies

EGR Position Sensor

Eng, EGR, FT, MF

%

Varies

EGR Position Sensor

EGR

Volts

Varies

EGR Position Variance

EGR

Counts

Varies

EGR Solenoid Command

EGR

%

Varies

Engine Load

Eng , EGR, EVAP, FT, HO2S, MF, CH, FF, FR

0-99%

25-40% - Idle

25-40% - 2500 RPM

Engine Run Time

ALL

0:00:00

Varies

Engine Speed

ALL

RPM

750-950 RPM

EVAP Purge Solenoid Command (If Equipped)

Eng, EVAP, FT, HO2S

0-100%

Varies

EVAP Vent Solenoid Command (If Equipped)

Eng, EVAP

Venting/Not Venting

Venting

Fail Counter

FF, FR

Counts

Varies

Fans High Speed

CH

ON/OFF

Varies

Fans Low Speed

CH

ON/OFF

Varies

Fuel Level to Cluster

EVAP, IPC

%

Varies

Fuel Level Sensor

Eng, EVAP, FT, IPC

0-5 Volts

Varies

Fuel Level Sensor

Eng, EVAP, FT, IPC

%

Varies

Fuel Pump Relay Command

Eng, FT

On/Off

On

Fuel Tank Pressure Sensor (If Equipped)

Eng, EVAP

in H2O/mm Hg

Varies

Fuel Tank Pressure Sensor (If Equipped)

Eng, EVAP, FF, FR

0-5 Volts

Varies

Fuel Trim Cell

Eng, FT, FF, FR

Cell Number

Varies

Fuel Trim Learn

Eng, FT, FF, FR

Enabled/Disabled

Enabled

O2S/HO2S 1

Eng, EVAP, FT, HO2S, FF, FR

0-1,006 mV

Varies 400-800 mV

O2S/HO2S 1 Ready

HO2S

Yes/No

Yes

O2S/HO2S 2

Eng, EVAP, FT, HO2S, FF, FR

0-1,006 mV

Varies 400-800 mV

IAC Position

Eng, EGR, FT, HO2S, CH, FF, FR

Counts

15-40 Counts

IAT Sensor

Eng, EGR, EVAP, FT, HO2S, MF, CH, FF, FR

-39° to +140°C (-38° to +284°F)

Varies

Ignition 1 Signal

Eng, EGR, EVAP, FT, HO2S, MF, CH, IPC

Volts

12.0-14.5 Volts

IMT Valve Command (If Equipped)

Eng

On/Off

Off

Injector PWM

Eng, FT, HO2S, MF, FF, FR

0-9 ms

4.6-5.4 ms

Knock Retard

Eng, EGR, CH

Degrees

Varies

KS Active Counter

Eng

Counts

Varies

Long Term FT

Eng, EVAP, FT, HO2S, FT, FF, FR

-100% to +100%

0%

Long Term FT Avg.

FT

-100% to +100%

0%

Loop Status

Eng, EVAP, FT, HO2S, FF, FR

Open Loop/Closed Loop

Closed Loop

Low Fuel Lamp Command (If Equipped)

IPC

On/Off

Off

MAP Sensor

Eng, EGR, EVAP, FT, HO2S, MF, FF, FR

kPa

38-50 kPa

Varies with Altitude

MAP Sensor

Eng, MF, FF, FR

0-5 Volts

0.9-1.7 Volts

MIL Command

Eng, IPC

On/Off

Off

Mileage Since First Failure

FF, FR

km - miles

Varies

Mileage Since Last Failure

FF, FR

km - miles

Varies

Misfire Current Cyl. 1-4

MF

0-255 Counts

0

Misfire History Cyl. 1-4

MF

0-65,535 Counts

0

Not Run Counter

FF, FR

Counts

Varies

Pass Counter

FF, FR

Counts

Varies

PNP Switch

Eng, EGR, IPC

Park/Neutral/In Gear

Park/Neutral

Power Enrichment

FT, HO2S, MF, FF, FR

Active/Inactive

Inactive

Power Steering Switch (If Equipped)

Eng, CH

High Pressure/Normal Pressure

Normal Pressure

Rich/Lean to Lean/Rich Ratio Sensor 1

FT, HO2S

Counts

Varies

Rich/Lean Transition Sensor 1

FT, HO2S

Counts

Varies

Rough Road Sensor (If Equipped)

MF

0-5 Volts

2-3 Volts

Short Term FT Avg.

FT

-25% to +25%

-3% to +3%

Short Term FT

Eng, EVAP, FT, HO2S, FF, FR

-25% to +25%

-3% to +3%

Spark

Eng, FT, HO2S, MF, CH

-20 to +40 Degrees

2-10 Degrees

Start Up ECT

EVAP, HO2S, CH, FF, FR

-39° to +140°C (-38° to +284°F)

Varies

Start Up IAT

EVAP, HO2S, CH, FF, FR

-39° to +140°C (-38° to +284°F)

Varies

SVS Lamp Command (If Equipped)

IPC

On/Off

Off

TCC Enable Solenoid Command (If Equipped)

Eng, MF

On/Off

Off

Total Fuel Trim Average

EVAP, FT, HO2S

-100 to +100%

Varies

Total Misfire

MF

Counts

0

TP Sensor

Eng, EGR, EVAP, FT, HO2S, MF, FF, FR

0-5 Volts

0.0-0.3 Volts

TP Sensor

Eng, EGR, EVAP, FT, HO2S, MF, FF, FR

%

5-15 %

TWC Temperature Calculated

MF

Temperature

Varies

Vehicle Security Status (If Equipped)

Eng, IPC

Enabled/Disabled

Disabled

Vehicle Speed Sensor

Eng, EGR, EVAP, FT, HO2S, MF, CH, IPC, FF, FR

Km/h

mph

0 km/h

(0 mph)