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 - Engine Controls is completed.
    • No DTCs
    • On-board diagnostics (OBDs) 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.

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 Symptoms - Engine Controls for diagnosis.

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.

ED: Engine Data

EVAP: EVAP Data

FT: Fuel Trim Data List

HO2S: Heated Oxygen Sensor Data

ID: Ignition Data

MF: Misfire Data List

TAC: Throttle Actuated Control Data List

CC: Cruise Control Data List

Scan Tool Parameter

Data List

Parameter Range/Units

Typical Data Values

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

A/C Relay Command

ED, MF

On/Off

Off

A/C Request Signal

ED

Yes/No

No

Air Fuel Ratio

ED, FT

Ratio

14.7:1

APP Average

TAC

Counts

Counts

APP Indicated Angle

ED, ID, FT, TAC, CC, EVAP

0-96%

0%

APP Sensor 1

TAC

%/Volts

0%/1.02 Volts

APP Sensor 1 Circuit Status

TAC

OK

OK

APP Sensor 2

TAC

%/Volts

0%/4.04 Volts

APP Sensor 2 Circuit Status

TAC

OK

OK

APP Sensor 1 and 2

TAC

Agree/Disagree

Agree

BARO

ED, EVAP, ID, EE, FT

kPa

65-104 kPa/Varies w/Altitude

Cam Phase Angle Actual

ED

Degrees

Cam Phase Angle Desired

ED

Degrees

Cam Phase Angle Variance

ED

Degrees

Camshaft Phase Solenoid

ED

%

Varies

Catalytic Converter Projection Active

FT, HO2S

Yes/No

No

CKP Active Counter

ED

1-250

9-250

CMP Active Counter

ED, ID

Counts

Varies

CMP Sensor

ED, ID

RPM

Varies

Cold Start-Up

ED, EVAP

Yes/No

Varies

Crank Request Signal

ED

Yes/No

No

Cruise Control Active

ED, TAC, CC

Yes/No

No

Cruise Disengage 1 History

CC

Varies

Varies

Cruise Disengage 2 History

CC

Varies

Varies

Cruise Disengage 3 History

CC

Varies

Varies

Cruise Disengage 4 History

CC

Varies

Varies

Cruise Disengage 5 History

CC

Varies

Varies

Cruise Disengage 6 History

CC

Varies

Varies

Cruise Disengage 7 History

CC

Varies

Varies

Cruise Disengage 8 History

CC

Varies

Varies

Cruise On/Off Switch

TAC, CC

On/Off

Off

Cruise Release Clutch/TCC Pedal Switches

ED, TAC, CC

Engaged/Released

Released

Cruise Resume/Accel Switch

TAC, CC

On/Off

Off

Cruise Set/Coast Switch

TAC, CC

On/Off

Off

Cycles of Misfire Data

MF

0-100 Counts

Varies

Decel Fuel Cutoff

ED, FT, HO2S

Active/Inactive

Inactive

Desired Idle Speed

ED, EE, TAC

RPM

PCM Controlled

EC Ignition Relay Feedback

ED, EVAP

Volts

B+

ECT Sensor

ED, EVAP, FT, ID, MF

-40 to +151°C (-40 to +303°F)

88-105°C (190-221°F) Depends on ambient temperature

Engine Load

ED, FT, MF, TAC, CC, ID, EVAP

0-100%

23-24% @ Idle

7-42% @ 2,500 RPM

Engine OFF Time

EVAP

Time

Varies

Engine Oil Level Switch

ED

OK/Low

OK

Engine Oil Pressure Switch

ED

OK/Low

OK

Engine Run Time

All

Hrs, Min, Sec

Varies

Engine Speed

All

0-10,000 RPM

500-700 RPM

Engine Torque

TAC

N·m/lb ft

16-24 N·m/11-17 lb ft

EVAP Fault History

EVAP

Fault/No Fault

No Fault

EVAP Purge Solenoid Command

ED, EVAP

0-100%

10-30%

EVAP Test Abort Reason

EVAP

--

Lost Enable

EVAP Test Result

EVAP

--

No Result

EVAP Test State

EVAP

--

Test Complete

EVAP Vent Solenoid Command

ED, EVAP

Not Venting/Venting

Venting

Fuel Tank Pressure Sensor

ED

mm/Hg/In H2O

Varies

Fuel Tank Pressure Sensor

EVAP

mm/Hg/In H2O/Volts

Varies

Fuel Tank Pressure Sensor

EVAP

mm/Hg/in H20

--

Fuel Trim Cell

ED, EVAP, FT

0-23

16, 17, 21

Fuel Level Sensor

ED, EVAP

0-100 %

Varies

Fuel Pump Relay Command

ED

On/Off

On

Fuel Tank Level Remaining

ED, EVAP

%

Varies

Fuel Trim Learn

ED, FT

Enable/Disable

Enable

Generator F-Terminal Signal

ED

Percent

Varies

Generator L-Terminal Signal Command

ED

ON/OFF

OFF

HO2S 1

ED, EVAP, FT

mV

10-1,000 mV and Varying

HO2S 2

ED, FT

mV

10-1,000 mV and Varying

HO2S 1 Heater

HO2S

AMP

Varies

HO2S 1 Heater Current

FT

Amps

Varies

HO2S 2 Heater

HO2S

AMP

Varies

HO2S 2 Heater Current

FT

Amps

Varies

IAT Sensor

ED, EVAP, ID, FT

-40 to +151°C (-40 to +303°F)

Depends on ambient temperature

Ignition 1 Signal

ED, EVAP, FT, ID, TAC, CC

0-25 volts

11.5-14.5 Volts

Initial Brake Apply Signal

ED

Applied/Released

Released

Injector PWM

ED, FT, MF

Milliseconds

2-6 ms

Knock Retard

ED, ID

0-16°

Long Term FT

ED, EVAP, FT

%

Near 0%

Long Term FT Avg

FT

%

Varies

Loop Status

ED, EVAP, FT

Open/Closed

Closed

MAF Sensor

ED, EVAP, FT, ID, MF, TAC

g/s

Varies

MAF Sensor

EVAP, FT

Hz

Varies

MAP Sensor

ED, EVAP, FT, ID, TAC, MF

kPa

20-48 kPa

Medium Resolution Resync Counter

ED, ID

Counts

0

Mileage Since DTC Cleared

ED

Miles

Varies

MIL Command

ED, ID

Off/On

Off

MIL Command Requested By DTC

ED, ID

Yes/No

No

Misfire Current Cyl #1

MF

Varies

0

Misfire Current Cyl #2

MF

Varies

0

Misfire Current Cyl #3

MF

Varies

0

Misfire Current Cyl #4

MF

Varies

0

Misfire Current Cyl #5

MF

Varies

0

Misfire History Cyl #1

MF

Varies

0

Misfire History Cyl #2

MF

Varies

0

Misfire History Cyl #3

MF

Varies

0

Misfire History Cyl #4

MF

Varies

0

Misfire History Cyl #5

MF

Varies

0

Non-driven Wheel Speed

CC

MPH

Varies

PCM reset

ED, EVAP, ID

Yes/No

No

Power Enrichment

ED, FT, MF

Active/Inactive

Inactive

Reduced Engine Power

ED, TAC, CC

Active/Inactive

Inactive

Reference Voltage 1 Signal

TAC, ID

Volts

5.03 V

Reference Voltage 2 Signal

TAC, ID

Volts

5.03 V

Short Term FT

ED, EVAP, FT

%

Near 0%

Short Term FT Avg

FT

%

Varies

Spark

ED, FT, ID, MF

Degrees

11-20°

Start Up ECT

ED, FT

°C/°F

Varies

Stop Lamp Pedal Switch

CC

Applied/Released

Released

Starter Relay Command

ED

On/Off

Off

Start-up IAT

EVAP, FT, HO2S

Degrees

Varies

TCC Enable Solenoid Command

ED, MF, CC

ON/OFF

OFF

Torque Delivered Signal

TAC

ft. lbs.

--

Torque Request Signal

TAC

ft. lbs.

--

Total Misfire Count

ED, MF

Numeric

0

TP Desired Angle

ED, EVAP, TAC, CC

%

4.2%

TP Indicated Angle

ED, EVAP, FT, ID, TAC, MF, CC

%

4.2%

TP Sensor 1 Learn Minimum

TAC

Volts

--

TP Sensor 2 Learn Minimum

TAC

Volts

--

TP Sensors 1 and 2

TAC

Agree/Disagree

Agree

TP Sensor 1

TAC

0-100%

4%

TP Sensor 2

TAC

0-100%

4%

TP Sensor 1

TAC

0-5 Volts

4.24 Volts

TP Sensor 2

TAC

0-5 Volts

0.78 Volt

Traction Control Signal

TAC, CC

Active/Inactive

Inactive

Traction Control Signal

CC

Active/Inactive

Inactive

TWC Temperature Calculated

FT

C/F

350°C

VCM/PCM in VTD Fail Enable

ED

Yes/No

No

Vehicle Speed Sensor

All

km/h

mph

0

VTD Fuel Disable

ED

Active/Inactive

Inactive

VTD Password

ED

Fault/OK

OK

VTD Auto. Learn Timer

ED

Active/Inactive

Inactive

VTD Fuel Disable Until Ignition Off

ED

Yes/No

No

Warm-up W/O Non-Emission Faults

ED

Numeric

Varies

Warm-up W/O Emission Faults

ED

Numeric

Varies