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 - Vehicle 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.

The parameters listed below may not be available on all applications.

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 of the data lists indicated below except Output Driver Data List.

Eng: Engine Data List

EE: Enhanced Evaporative Emission (EVAP) Data

FT: Fuel Trim Data List

H02S: Heated Oxygen Sensor (HO2S) Data List

Ign: Ignition System Data List

Ind: Induction System Data List

MF: Misfire Data List

OD: Output Driver Data List

TAC: Throttle Actuator Control (TAC) Data List

Scan Tool Parameter

Data List

Parameter Range/Units

Typical Data Values

Operating Conditions: Engine Idling/Radiator Hose Hot/Closed Throttle/Park/Closed Loop/Accessories OFF

5-Volt Reference 1 Circuit Status

EE, Ign, Ind, TAC

OK/Fault

OK

5-Volt Reference 2 Circuit Status

EE, Ign, Ind, TAC

OK/Fault

OK

5-Volt Reference 1

EE, Ign, Ind, TAC

Volts

4.5 V

5-Volt Reference 2

EE, Ign, Ind, TAC

Volts

4.5 V

A/C Relay Circuit Status

OD

OK, Incomplete, Short B+, Short Gnd/Open

OK/Incomplete

A/C Relay Command

Eng , Ind, MF, TAC

On/Off

Varies

Air Flow Calculated

EE, Eng, FT, HO2S, Ind, MF, TAC

Grams Per Seconds (g/s)

1-9 g/s @ idle

Ambient Air Temperature

EE, Eng

°C/°F

Varies

APP Indicated Angle

EE, Eng, FT, HO2S, Ign, Ind, MF, TAC

0-100%

0

APP Sensor 1

TAC

0-100%

0%

APP Sensor 2

TAC

0-100%

0%

APP Sensor 1 and 2

TAC

Agree/Disagree

Agree

APP Sensor 1 Indicated Position

TAC

%

0%

APP Sensor 2 Indicated Position

TAC

%

--

APP Sensors

TAC

%

0%

BARO

EE, Eng, FT, HO2S, Ign, Ind

kPa

50-104 kPa/ Varies w/Altitude

BPP Circuit Signal

Eng, TAC

Applied/Released

Released

BPP Signal

TAC

Applied/Released

Released

Calculated TWC Temp Bank 1

FT, MF

Degrees C/F

315-427°C (600-800°F)

Calculated TWC Temp Bank 2

FT, MF

Degrees C/F

315-427°C (600-800°F)

Catalytic Converter Protection Active

FT, HO2S

Yes/No

No

CKP Active Counter

Ign

0-250 Counts

Varies

CKP Resync Counter

Ign

Counts

0

CKP Sensor

Ign

RPM

500-700 RPM

CMP Active Counter

Ign, MF

0-250 Counts

Varies

CMP Sensor

Ign

RPM

1,000-1,400 RPM

Cold Start-Up

Eng, EE

Yes/No

Varies

CPP Switch

Eng, TAC

Applied Released

Released

Cruise Control Active

Eng, TAC

Active/Inactive

Inactive

Cycles of Misfire Data

MF

0-100 Counts

Varies

Cylinder 1-8 IC Circuit Status

MF, OD

OK, Incomplete, Short B+, Short Gnd/Open

OK

Cylinder 1-8 Injector Circuit Status

MF, OD

OK, Incomplete, Short B+, Short Gnd/Open

OK

Decel Fuel Cutoff

Eng, FT, HO2S

Active/Inactive

Inactive

Desired Idle Speed

EE, Eng, Ind, TAC

RPM

ECM Controlled

Distance Since DTC Cleared

Eng

km/miles

Varies

EC Ignition Relay Circuit Status

OD, TAC

OK, Incomplete, Short B+, Short Gnd/Open

OK/Incomplete

EC Ignition Relay Command

Eng, TAC

On/Off

On

EC Ignition Relay Feedback

Eng, TAC

Volts

2.25-2.95 Volts

ECT Sensor

All

-39 to +140°C (-38 to +284°F)

88-105°C (190-221°F)

Engine Load

All

0-100%

18% @ Idle

21% @ 2500 RPM

Engine Oil Level Switch

Eng

OK/Low

OK

Engine Oil Pressure Sensor

Eng, MF

PSI

30

Engine Oil Pressure Switch

Eng

OK/Low

OK

Engine Run Time

All

Hrs, Min, Sec

Varies

Engine Speed

All

0-10,000 RPM

500-700 RPM

Engine Speed Circuit Status

OD

OK, Incomplete, Short B+, Short Gnd/Open

OK

EVAP Purge Solenoid Circuit Status

EE, OD

OK, Incomplete, Short B+, Short Gnd/Open

OK/Incomplete

EVAP Purge Solenoid Command

EE, Eng, FT, HO2S

0-100%

10-25%

EVAP Vent Solenoid Circuit Status

OD

OK, Incomplete, Short B+, Short Gnd/Open

OK/Incomplete

EVAP Vent Solenoid Command

EE, Eng

Not Venting/Venting

Venting

Extended Travel BPP Switch

TAC

Applied/Released

Released

FC Circuit Status

OD

OK, Incomplete, Short B+, Short Gnd/Open

OK/Incomplete

Fuel Level Sensor Left

EE

0-5 Volts

Varies

Fuel Level Sensor Right

EE

0-5 Volts

Varies

Fuel Pump Relay Circuit Status

Eng, OD

OK, Incomplete, Short B+, Short Gnd/Open

OK/Incomplete

Fuel Pump Relay Command

Eng

On/Off

ON

Fuel Tank Level Remaining

EE, Eng, FT, MF

0-100%

Varies

Fuel Tank Pressure Sensor

EE, Eng

-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

98 Liters (25.9 Gallons) or 96.2 Liters (25 Gallons)

Varies with Fuel Tank Option

Fuel Trim Cell

Eng, FT

0-23

19

Fuel Trim Learn

FT

Enabled/Disabled

Enabled, May Toggle

Fuel Volatility

EE, FT

Low/Moderate/High

Varies

HO2S Bank 1 Sensor 1

EE, Eng, FT, HO2S, Ind

Millivolts

10-1,000 mV and Varying

HO2S Bank 1 Sensor 2

Eng, FT, HO2S

Millivolts

10-1,000 mV and Varying

HO2S Bank 2 Sensor 1

EE, Eng, FT, HO2S, Ind

Millivolts

10-1,000 mV and Varying

HO2S Bank 2 Sensor 2

Eng, FT, HO2S

Millivolts

10-1,000 mV and Varying

HO2S BN 1 Sensor 1 Heater

HO2S

Amps

0.7-0.9 Amps

HO2S BN 1 Sensor 2 Heater

HO2S

Amps

0.4-0.6 Amps

HO2S BN 2 Sensor 1 Heater

HO2S

Amps

0.7-0.9 Amps

HO2S BN 2 Sensor 2 Heater

HO2S

Amps

0.4-0.6 Amps

HO2S BNK 1 Sen 1 Heater Circuit Status

OD

OK, Incomplete, Short B+, Short Gnd/Open

OK/Incomplete

HO2S BNK 1 Sen 2 Heater Circuit Status

OD

OK, Incomplete, Short B+, Short Gnd/Open

OK/Incomplete

HO2S BNK 2 Sen 1 Heater Circuit Status

OD

OK, Incomplete, Short B+, Short Gnd/Open

OK/Incomplete

HO2S BNK 2 Sen 2 Heater Circuit Status

OD

OK, Incomplete, Short B+, Short Gnd/Open

OK/Incomplete

HO2S Bnk 1 Sensor 1 Heater Command

HO2S

On/Off

ON

HO2S Bnk 1 Sensor 1 Heater Command

HO2S

%

100%

HO2S Bnk 1 Sensor 2 Heater Command

HO2S

On/Off

ON

HO2S Bnk 1 Sensor 2 Heater Command

HO2S

%

100%

HO2S Bnk 2 Sensor 1 Heater Command

HO2S

On/Off

ON

HO2S Bnk 2 Sensor 1 Heater Command

HO2S

%

100%

HO2S Bnk 2 Sensor 2 Heater Command

HO2S

On/Off

ON

HO2S Bnk 2 Sensor 2 Heater Command

HO2S

%

100%

Hot Open Loop

FT, HO2S

Active/Inactive

Inactive

IAT Sensor

All

-39 to +140°C (-38 to +284°F)

35°C (91°F) Depends on Ambient Temperature

Ignition Accessory Signal

Eng, TAC

On/Off

ON

Ignition 1 Signal

All

0-25 Volts

11.5-14.5 Volts

Injector 1-8 Disabled Due To Misfire

MF

Yes/No

No

Inj. PWM Bank 1

Eng, FT, HO2S, MF

Milliseconds

2-6

Inj. PWM Bank 2

Eng, FT, HO2S, MF

Milliseconds

2-6

Intake Manifold Pressure

Eng, FT, Ind

kPa/psi

Varies

Knock Retard

Ign

0.0-16°

Long Term FT Bank 1

EE, Eng, FT, HO2S

Percentage

Near 0%

Long Term FT Bank 2

EE, Eng, FT, HO2S

Percentage

Near 0%

Loop Status

EE, Eng, FT, HO2S

Open/Closed

Closed

MAF Performance Test

FT, Ind, TAC

OK/Fault

OK

MAF Sensor

All

Grams Per Seconds (g/s)

1-9 g/s @ Idle, Depends on Altitude

15-26 g/s @ 2,500 RPM, Depends on Altitude

MAF Sensor

Ind

0-31,999 Hz

1,150-1,350 Hz

MAP Performance Test 1

FT, Ind, TAC

OK/Fault

OK

MAP Performance Test 2

FT, Ind, TAC

OK/Fault

OK

MAP Sensor

All

kPa

20-48 kPa

MAP Sensor

Ind

Volts

1.0-2.0 Volts

Varies with Altitude

MIL Circuit Status

OD

OK, Incomplete, Short B+, Short Gnd/Open

OK/Incomplete

MIL Command

Eng

Off/On

Off

MIL Requested by DTC

All

Yes/No

No

Misfire Current Cyl. 1-8

MF

0-200 Counts

0

Misfire History Cyl. 1-8

MF

0-65,535 Counts

0

PNP Switch

Eng

P/N

Yes/No in gear

P/N

Power Enrichment

Eng, FT, HO2S, MF

Active/Inactive

Inactive

Reduced Engine Power

TAC

Active/Inactive

Inactive

Short Term FT Bank 1

EE, Eng, FT, HO2S

Percentage

Near 0%

Short Term FT Bank 2

EE, Eng, FT, HO2S

Percentage

Near 0%

Spark

Eng, FT, HO2S, Ign, Ind, MF

Degrees

10-17°

Starter Relay Circuit Status

OD

OK, Incomplete, Short B+, Short Gnd/Open

OK/Incomplete

Start-Up ECT

EE, HO2S

°C/°F

Varies

Start-Up IAT

HO2S

°C/°F

Varies

TAC Forced Engine Shutdown

TAC

Yes/No

No

TAC Motor

TAC

Enabled/Disabled

Enabled

TAC Motor Command

TAC

0-100%

15-35%

Torque Management Spark Retard

Ign

Degrees

Total Knock Retard

Ign

Degrees

Total Misfire

MF

Counts

Varies

TP Desired Angle

TAC

0-100%

5.5%

TP Indicated Angle

All

0-100%

5.5%

TP Performance Test

FT, Ind, TAC

OK/Fault

OK

TP Sensor 1 Learned Minimum

TAC

Volts

0.55

TP Sensor 2 Learned minimum

TAC

Volts

0.55

TP Sensors 1 and 2

TAC

Agree/Disagree

Agree

TP Sensor 1 Indicated Position

TAC

%

5%

TP Sensor 2 Indicated Position

TAC

%

5%

Vehicle Speed Circuit Status

OD

OK, Incomplete, Short B+, Short Gnd/Open

OK/Incomplete

Vehicle Speed Sensor

All

km/h

mph

0

Warm-Ups w/o Emission Faults

Eng

0-255 Counts

Varies

Warm-Ups w/o Non-Emission Faults

Eng

0-255 Counts

Varies

Warm-Ups Since DTC Cleared

Eng

Counts

Varies

Wide Open Throttle

TAC

Yes/No

No