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 - Vehicle 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.

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:

AIR: AIR Data List

ALL: Parameter is in All Data Lists

EGR: EGR Data List

ENG: Engine Data List

EVAP: EVAP Data

FT: Fuel Trim Data List

HO2S: HO2S Data List

IGN: Ignition Data List

IND: Induction Data

MF: Misfire Data List

TAC: TAC Data List

Scan Tool Parameter

Data List

Parameter Range/Units

Typical Data Values

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

5-volt Reference 1

AIR, EGR, EVAP, IGN, IND, TAC

Volts

4.5

5-volt Reference 1 Circuit Status

AIR

OK/Fault

OK

5-volt Reference 2

AIR, EGR, EVAP, IGN, IND, TAC

Volts

4.5

5-volt Reference 2 Circuit Status

AIR

OK/Fault

OK

A/C Relay Command

AIR, EGR, ENG, IND, MF, TAC

On/Off

Off

Air Flow Calculated

AIR, ENG, EVAP, FT, HO2S, IND, MF, TAC

g/s

3-7

AIR Indicated Pressure

AIR

kPa/PSI

0.0

AIR Pressure Sensor

AIR

kPa/psi

Near BARO

AIR Pressure Sensor

AIR

Volts

2.7

AIR Pressure Sensor Variance

AIR

kPa/psi

0.00

AIR Pump Relay Circuit Status

AIR

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

OK/Incomplete

AIR Pump Relay Command

AIR

ON/OFF

OFF

AIR Solenoid Circuit Status

AIR

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

OK/Incomplete

AIR Solenoid Command

AIR

ON/OFF

OFF

Ambient Air Temperature

ENG

C/F

Varies

APP Indicated Angle

ALL

0-100%

0

APP Sensor

TAC

Volts

0.0

APP Sensor 1

TAC

0.9-4.5 Volts

0.90

APP Sensor 1 Indicated Position

TAC

%

0.0

APP Sensor 2

TAC

0.42-2.25 Volts

0.43

APP Sensor 2 Indicated Position

TAC

%

0.0

APP Sensor 1 and 2

TAC

Agree/Disagree

Agree

BARO

AIR, EGR, ENG, EVAP, FT, HO2S, IGN, IND

65-104 kPa

Varies with altitude

BPP Circuit Signal

TAC

Applied/Released

Released

BPP Signal

ENG, TAC

Applied / Released / Invalid

Released

Catalytic Converter Protection Active

FT, HO2S

Yes/No

No

Calc. TWC Temp.

FT, MF

°C/°F

Varies

CKP Active Counter

IGN

Counts

Incrementing

CKP Resync Counter

IGN

Counts

Varies

CKP Sensor

IGN

RPM

Engine Idle Speed

CMP Active Counter

IGN

Counts

Incrementing

CMP Sensor

IGN, MF

RPM

Engine Idle Speed

Cold Startup

AIR, EVAP

YES/NO

Varies

Commanded A/F Equivalence Ratio

ENG

--

1

Cruise Control Active

TAC

Yes/No

No

Cycles of Misfire Data

MF

0-99

Incrementing

Cylinder 1-8 Circuit Status

MF

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

OK

Cylinder 1-8 Injector Circuit Status

MF

Fault/OK

OK

Decel. Fuel Cutoff

EGR, ENG, FT, HO2S

Active/Inactive

Inactive

Desired EGR Position

EGR

%

0

Desired Idle Speed

EVAP, IND, TAC

RPM

650

Distance Since DTC Cleared

ENG

Miles/Kilometers

Varies

EC Ignition Relay Circuit Status

TAC

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

OK/Incomplete

EC Ignition Relay Command

ENG, TAC

On/Off

On

EC Ignition Relay Feedback Signal

ENG, TAC

Volts

Battery Voltage

ECT Sensor

ALL

-39 to +140°C/-38 to +284°F

85-105°C/185-220°F

EGR Flow Test Count

EGR

Counts

1

EGR Learned Minimum Position

EGR

Volts

0.57

EGR Position Sensor

EGR, FT, IND, MF

%

0

EGR Position Sensor

EGR

Volts

0.57

EGR Position Variance

EGR

%

--

EGR Solenoid Circuit Status

EGR

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

OK/Incomplete

EGR Solenoid Command

EGR

%

0

Engine Load

ALL

%

25

Engine Oil Level Switch

ENG

OK/Low

OK

Engine Oil Life Remaining

IPC

%

Varies

Engine Oil Pressure Switch

MF

OK/Low

OK

Engine Run Time

ALL

0:00:00

Varies

Engine Speed

AIR, EGR, ENG, EVAP, FT, HO2S, IGN, MF, TAC

RPM

650

EVAP Fault History

EVAP

Fault/No Fault

No Fault

EVAP Purge Solenoid Command

ENG, EVAP, FT, HO2S

%

Varies

EVAP Purge Solenoid Circuit Status

EVAP

OK/Short B+/Short Gen/Open/Incomplete

OK/Incomplete

EVAP Vent Solenoid Command

ENG, EVAP

Venting/Not Venting

Venting

EVAP Vent Solenoid Circuit Status

EVAP

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

OK/Incomplete

Ext. Travel BPP Signal

TAC

Applied/Released

Released

Fuel Level Sensor

EVAP

0-5 Volts

Varies

Fuel Pump Relay Command

ENG

On/Off

On

Fuel Pump Relay Circuit Status

ENG

OK/Short B+/Short Gnd/Open

OK/Incomplete

Fuel Tank Level Remaining

ENG, EVAP, FT, MF

Gal/L

Varies

Fuel Tank Pressure Sensor

EVAP

Volts

1.5

Fuel Tank Pressure Sensor

ENG, EVAP

in H2O/mm Hg

0.00

Fuel Tank Rated Capacity

EVAP

Gal/L

18.5/69.9

Fuel Trim Cell

ENG, FT

Cell Number

17

Fuel Trim Learn

FT

Enabled/Disabled

Enabled

Fuel Trim System Test State

FT

Disabled, Enabled, Run Purge Test, Monitoring

Varies

Fuel Volatility

FT

Low/Moderate/High

Varies

HO2S Bank 1 or Bank 2 Sensor 1

AIR, ENG, EVAP, FT, HO2S, IND

mV

80-850

HO2S Bank 1 Sensor 2

ENG, FT, HO2S

mV

Varies 400-800 mV

HO2S Bank 1 or Bank 2 Sensor 1 Heater

HO2S

amps

0.60-0.80

HO2S Bank 1 Sensor 2 Heater

HO2S

amps

0.60-0.80

HO2S Bank 1 Sensor 1 Heater Circuit

HO2S

Incomplete, Short to gnd/Open, short to B+

OK

HO2S Bank 1 Sensor 1 Heater Command

HO2S

%

60-99

HO2S Bank 1 Sensor 1 Heater Command

HO2S

ON/OFF

ON

HO2S Bank 1 Sensor 2 Heater Circuit

HO2S

Incomplete, Short to gnd/Open, short to B+

OK

HO2S Bank 1 Sensor 2 Heater Command

HO2S

%

60-99

HO2S Bank 1 Sensor 2 Heater Command

HO2S

ON/OFF

ON

HO2S Bank 2 Sensor 1 Heater Circuit

HO2S

Incomplete, Short to gnd/Open, short to B+

OK

HO2S Bank 2 Sensor 1 Heater Command

HO2S

%

60-99

HO2S Bank 2 Sensor 1 Heater Command

HO2S

ON/OFF

ON

Hot Open Loop

HO2S, FT

Active/Inactive

Inactive

IAT Sensor

ALL

-39 to +140°C/-38 to +284°F

Varies

Ignition Accessory Signal

ENG, TAC

ON/OFF

OFF

Ignition 1 Signal

ALL

Volts

Battery Voltage

Injector PWM Bank 1 or Bank 2

ENG, FT, HO2S, MF

ms

2.0-5.4

Injector 1-8 Disabled Due To Misfire

MF

Yes/No

No

Intake Manifold Pressure

FT, IND

kPa

70-75

Knock Detected Cyl.1-8

IGN

YES/NO

NO

Knock Retard

EGR, IGN

0-191 Degrees

0

Long Term FT Bank 1 or Bank 2

AIR, ENG, EVAP, FT, HO2S

-100 to +100%

0% ± 10%

LT FT Test Avg. Bank 1 or Bank 2

FT

%

1%

LT FT Avg. Bank 1 or Bank 2 w/o purge

FT

%

1%

Loop Status

AIR, ENG, EVAP, FT, HO2S

Open/Closed

Closed

MAF Performance Test

FT, TAC

OK/Fault

OK

MAF Sensor

ALL

g/s

3-7

MAF Sensor

IND

Hz

2800

MAP Performance Test 1

FT, IND, TAC

OK/Fault

OK

MAP Performance Test 2

FT, IND, TAC

OK/Fault

OK

MAP Sensor

AIR, EGR, ENG, EVAP, FT, HO2S, IGN, IND, MF, TAC

kPa

30 kPa

MAP Sensor

IND

Volts

0.95-1.06

MIL Circuit Status

ENG

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

OK/Incomplete

MIL Command

ENG

On/Off

Off

MIL Requested by DTC

AIR, EGR, EVAP, FT, HO2S, IGN, IND, MF, TAC

Yes/No

No

Misfire Current Cyl.1-8

MF

0-255 Counts

0

Misfire History Cyl. 1-8

MF

0-255 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 or Bank 2

AIR, ENG, EVAP, FT, HO2S

-100 to +100%

0% ± 10%

Spark

ENG, FT, HO2S, IGN, IND, MF,

°

9-11

Start Up ECT

AIR, EVAP, HO2S

-39 to +140°C/-38 to +284°F

Varies

Start Up IAT

AIR, EVAP, HO2S

-39 to +140°C/-38 to +284°F

Varies

ST FT Test Avg. Bank 1 or Bank 2

FT

%

1

TAC Forced Engine Shutdown

TAC

YES/NO

NO

TAC Motor

TAC

Enabled/Disabled

Enabled

TAC Motor Command

TAC

%

25

TCS Torque Request Signal

TAC

Nm / lb ft

3/2

TCS Torque Request Signal

TAC

%

5

Torque Delivered Signal

TAC

%

1

Torque Management Spark Retard

IGN

°

0

Total Knock Retard

IGN

°

0

Total Misfire

MF

Counts

0

TP Desired Angle

TAC

%

2

TP Indicated Angle

AIR, EGR, ENG, EVAP, FT, HO2S, IGN, MF, TAC

0-99%

2-3

TP Performance Test

IND, TAC, FT

OK/Fault

OK

TP Sensor 1 Learned Min

TAC

Volts

Varies

TP Sensor 2 Learned Min

TAC

Volts

Varies

TP Sensor 1

TAC

Volts

4.1-4.5

TP Sensor 1 Indicated Position

TAC

%

2 %

TP Sensors 1 and 2

TAC

Agree/Disagree

Agree

TP Sensor 2

TAC

Volts

0.5-0.8

TP Sensor 2 Indicated Position

TAC

%

2 %

Vehicle Speed Sensor

ALL

km/mi

0

Warm-ups Since DTC Cleared

ENG

Counts

Varies

Warm-ups w/o Emission Faults

ENG

Counts

0

Warm-ups w/o Non-emission Faults

ENG

Counts

0

Wide Open Throttle

TAC

YES/NO

NO