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:

ALL: Parameter is in All Data Lists

CMP: CMP Actuator Data List

ENG: Engine Data List

EVAP: EVAP Data List

FT: Fuel 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 or 2

EVAP, IGN, IND, TAC

Volts

4.5

5-Volt Reference 1 or 2 Circuit Status

EVAP, IGN, IND, TAC

OK/Fault

OK

A/C Relay Command

ENG, IND, MF, TAC

On/Off

Off

Air Flow Calculated

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

g/s

--

Ambient Air Temperature

ENG, EVAP

°C/°F

Varies

APP Indicated Angle

ALL

0-100%

0.0

APP Sensors

TAC

Volts

0.0

APP Sensor 1

TAC

0.9-4.5 Volts

0.92 Volt

APP Sensor 1 Indicated Position

TAC

%

0.0

APP Sensor 2

TAC

0.42-2.25 Volts

0.43 Volt

APP Sensor 2 Indicated Position

TAC

%

0.0

APP Sensor 1 and 2

TAC

Agree/Disagree

Agree

BARO

ENG, EVAP, FT, HO2S, IGN, IND

65-104 kPa -16 psi

Varies with altitude

BARO Sensor

IND

Volts

Varies

BPP Circuit Signal

TAC

Applied/Released

Released

BPP Signal

TAC

Applied/Released/Invalid

Released

CAC Int Pump Relay Circuit Status

IND

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

OK

CAC Int Pump Relay Command

IND

On/Off

Varies

Calc. TWC Temp. Bank 1 or Bank 2

FT, MF

°C/°F

Varies

Catalytic Converter Protection Active

FT, HO2S

Yes/No

No

CKP Active Counter

IGN

Counts

Incrementing

CKP Resync Counter

IGN

Counts

Varies

CKP Sensor

IGN

RPM

Engine idle speed

Cmmd. A/F Equivalence Ratio

ENG, FT, HO2S, IND

Ratio

14.7:1

CMP Active Counter

CMP, IGN

Counts

Incrementing

CMP Sensor

CMP, IGN, MF

RPM

Engine idle speed

Cold Startup

ENG, EVAP

YES/NO

Varies

Cruise Control Active

ENG, TAC

Active/Inactive

Inactive

Cycles of Misfire Data

MF

0-99

Incrementing

Cylinder 1-8 IC Circuit Status

MF

Incomplete/Short B+/Short Gnd/ Open

OK

Cylinder 1-8 Injector Circuit Status

MF

Incomplete/Short B+/Short Gnd/Open

OK

Decel. Fuel Cutoff

ENG, FT, HO2S

Active/Inactive

Inactive

Desired Exh. CMP Bank 1 or Bank 2

CMP

Degrees

Varies

Desired Idle Speed

ENG, CMP, EVAP, IND, TAC

0-7,000 RPM

650 RPM

Desired Int. CMP Bank 1 or Bank 2

CMP

Degrees

Varies

Distance Since DTC Cleared

ENG

Miles/Kilometers

Varies

EC Ignition Relay Circuit Status

TAC

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

OK

EC Ignition Relay Command

ENG, TAC

On/Off

On

EC Ignition Relay Feedback Signal

ENG, TAC

Volts

13.5 V

ECT Sensor

ALL

-39 to +140°C/-38 to +284°F

85-105°C/185-220°F

Engine Load

ALL

0-99%

2%

Engine Off Time

EVAP

0:00:00

Varies

Engine Oil Level Switch

ENG, CMP

OK/Low

OK

Engine Oil Life Remaining

ENG, CMP

%

Varies

Engine Oil Pressure Sensor

ENG, CMP, MF

kPa/psi

Varies

Engine Oil Temperature Calculated

CMP

°C/°F

Varies

Engine Oil Temperature Sensor (if equipped)

CMP

°C/°F

Varies

Engine Run Time

ALL

0:00:00

Varies

Engine Speed

ALL

RPM

650 RPM

EVAP Fault History

EVAP

Vacuum/Purge Valve Leak/Small Leak/Weak Vacuum/No Test Result

Vacuum

EVAP Purge Solenoid Command

ENG, EVAP, FT, HO2S

0-100%

Varies

EVAP Purge Solenoid Circuit Status

EVAP

Incomplete/Fault/OK

Incomplete

EVAP Vent Solenoid Command

ENG, EVAP

Venting/Not Venting

Not Venting

EVAP Vent Solenoid Circuit Status

EVAP

Incomplete/Fault/OK

Incomplete

Exh. CMP Angle Bank 1 or Band 2

CMP

Degrees

Varies

Exh. CMP Bank 1 or Bank 2 Active Counter

CMP, IGN

Counts

Varies

Exh. CMP Bank 1 or Bank 2 Command

CMP

%

Varies

Exh. CMP Bank 1 or Bank 2 Variance

CMP

Degrees

Varies

Ext. CMP Solenoid Bn 1 or Bn 2 Circuit Status

CMP

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

OK

Ext. Travel BPP Signal

TAC

Applied/Released/Invalid

Released

Fuel Level Sensor - Left Tank

EVAP

0-5 Volts

Varies

Fuel Level Sensor - Right Tank

EVAP

0-5 Volts

Varies

Fuel Pump Relay Circuit Status

ENG

Incomplete/Fault/OK

OK

Fuel Pump Relay Command

ENG

On/Off

On

Fuel Tank Level Remaining

ENG, EVAP, FT, MF

%

Varies

Fuel Tank Pressure Sensor

EVAP

Volts

Varies

Fuel Tank Pressure Sensor

ENG, EVAP

in H2O/mm Hg

Varies

Fuel Tank Rated Capacity

EVAP

Liters/Gal

Varies

Fuel Trim Cell

ENG, FT

Varies

2

Fuel Trim Learn

FT

Enabled/Disabled

Enabled

Fuel Trim System Test State

FT

Disabled, Enabled, Run Purge Test, Monitoring

Varies

Fuel Volatility

EVAP, FT

Low/Moderate/High

Varies

HO2S Bank 1 or Bank 2 Sensor 1

ENG, EVAP, FT, HO2S, IND

mV

80-850

HO2S Bank 1 or Bank 2 Sensor 2

ENG, FT, HO2S

mV

Varies 400-800 mV

HO2S Bank 1 or Bank 2 Sensor 1 Heater

HO2S

amps

Varies

HO2S Bank 1 or Bank 2 Sensor 2 Heater

HO2S

amps

Varies

HO2S Bank 1 Sensor 1 Heater Command

HO2S

%

Varies

HO2S Bank 1 Sensor 1 Heater Command

HO2S

ON/OFF

ON

HO2S Bank 1 or Bank 2 Sensor 2 Heater Command

HO2S

%

Varies

HO2S Bank 1 or Bank 2 Sensor 2 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

IAT Sensor 2

ENG, EVAP, IND

-39 to +140°C

Varies

Ignition Accessory Signal

ENG, TAC

ON/OFF

ON

Ignition Off Time

ENG, EVAP

0:00:00

Varies

Ignition 1 Signal

ALL

0-25.5 Volts

12.8-14.2 Volts

Injector PWM Bank 1 or Bank 2

ENG, FT, HO2S, MF

0-9 ms

3.0-5.4 ms

Injector 1-8 Disabled Due To Misfire

MF

Yes/No

No

Int. CMP Angle Bank 1 or Bank 2

CMP

Degrees

Varies

Int. CMP Bank 1 or Bank 2 Active Counter

CMP, IGN

Counts

Varies

Int. CMP Bank 1 or Bank 2 Command

CMP

%

Varies

Int. CMP Bank 1 or Bank 2 Variance

CMP

Degrees

Varies

Int. CMP Solenoid Bn 1 or Bn 2 Circuit Status

CMP

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

OK

Intake Manifold Pressure

ENG, FT, IND

kPa

Varies

Knock Detected Cyl.1-8

IGN

YES/NO

NO

Knock Retard

IGN

0-191 Degrees

0

Long Term FT Bank 1 or Bank. 2

ENG, EVAP, FT, HO2S,

-100 to +100%

7-9%

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

ENG, EVAP, FT, HO2S

Open/Closed

Closed

MAF Performance Test

FT, TAC, IND

OK/Fault

OK

MAF Sensor

ALL

0-655 g/s

3-7 g/s

MAF Sensor

IND

0-9999 Hz

28 Hz

MAP Performance Test

FT, IND, TAC

OK/Fault

OK

MAP Performance Test 1

FT, IND, TAC

OK/Fault

OK

MAP Performance Test 2

FT, IND, TAC

OK/Fault

OK

MAP Sensor

ALL

kPa/psi

30 kPa (4.6 psi)

MAP Sensor

IND

Volts

1.06

MIL Circuit Status

ENG

OK/Incomplete/Short B+/Short Gnd

OK/Incomplete

MIL Command

ENG

On/Off

Off

MIL Requested by DTC

ALL

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

Park/Neutral/In Gear

Park/Neutral

Power Enrichment

ENG, FT, HO2S, MF

Active/Inactive

Inactive

Reduced Engine Power

TAC

Active/Inactive

Inactive

SC Inlet Pressure Sensor

FT, IND

kPa/psi

Varies

SC Inlet Pressure Sensor

IND

Volts

Varies

SC Inlet Pressure

FT, IND

kPa/psi

Varies

SCB Solenoid Circuit Status

IND

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

OK

SBC Solenoid Command

ENG, IND

%

Varies

Short Term FT Bank 1 or Bank 2

ENG, EVAP, FT, HO2S

-100 to +100%

-3% to +3%

Spark

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

°

--

Start Up ECT

EVAP, HO2S

-39 to +140°C/-38 to +284°F

Varies

Start Up IAT

EVAP, HO2S

-39 to +140°C/-38 to +284°F

Varies

ST FT Test Avg. Bank 1 or Bank 2

FT

%

--

TAC Forced Engine Shutdown

TAC

YES/NO

NO

TAC Motor

TAC

Enabled/Disabled

Enabled

TAC Motor Command

TAC

%

--

TCS Torque Delivered Signal

TAC

%

1 %

TCS Torque Request Signal

TAC

Nm

--

TCS Torque Request Signal

TAC

%

--

Torque Management Spark Retard

IGN

°

0

Total Knock Retard

IGN

°

0

Total Misfire

MF

0-9999

0

TP Desired Angle

TAC

%

2 %

TP Indicated Angle

ALL

0-99%

2-3 %

TP Performance Test

IND, TAC, FT

OK/Fault

OK

TP Sensor 1

TAC

0-5 Volts

0.5-0.8 Volts

TP Sensor 2

TAC

0-5 Volts

4.1-4.5 Volts

TP Sensor 1 Indicated Position

TAC

%

2 %

TP Sensor 2 Indicated Position

TAC

%

2 %

TP Sensor 1 Learned Min

TAC

0-5 Volts

Varies

TP Sensor 2 Learned Min

TAC

5-0 Volts

Varies

TP Sensors 1 and 2

TAC

Agree/Disagree

Agree

Vehicle Speed Sensor

ALL

km/mi

0

Warm-ups Since DTC Cleared

ENG

Counts

0

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