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 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.

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.

CMP: CMP Actuator Data

ED: Engine Data

EVAP: EVAP Data

FT: Fuel Trim Data List

HD: Hybrid Data

IND: Induction Data

MF: Misfire Data List

TAC: Throttle Actuated Control Data List

HO2S: HO2S Data

ID: Ignition Data

Scan Tool Parameter

Data List

Parameter Range/Units

Typical Data Values

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

5-Volt Reference 1

EVAP, ID, IND, TAC

Volts

4.5 Volts

5-Volt Reference 2

EVAP, ID, IND, TAC

Volts

4.5 Volts

A/C Relay Command

ED, MF, IND, TAC

On/Off

Off

Air Flow Calculated

ED, EVAP, FT, HO2S, IND, MF, TAC

g/s

3.5 g/s

Ambient Air Temp

ED, EVAP

Degrees

7°F (14°C)

Amp Control Mode

HD

--

High to Low

Amp Control Status

HD

Charging/Discharging

Charging

Amp Voltage

HD

Volts

14 Volts

APP Indicated Angle

ALL

0-96%

0%

APP Sensor 1

TAC

Volts

1.02 Volts

APP Sensor 1

TAC

%

17%

APP Sensor 1 Indicated Angle

TAC

%

0%

APP Sensor 2

TAC

Volts

4.04 Volts

APP Sensor 2

TAC

%

89%

APP Sensor 2 Indicated Angle

TAC

%

0%

APP Sensor 1 and 2

TAC

Agree/Disagree

Agree

APP Sensors

EVAP

%

0%

AUX Trans Fluid Pump Command

HD

%

0%

BARO

ED, EVAP, FT, HO2S, ID, IND

kPa

65-104 kPa/ Varies w/Altitude

BPP Circuit Signal

ED, HD, TAC

Applied/Released/ Invalid

Released

BPP Signal

ED

Applied/Released/ Invalid

Invalid

Brake Booster Pressure

HD

kPa

60 kPa

Calculated Starter Generator Torque

ED, HD

N·m

8-10 N·m

Catalytic Converter Protection Active

FT, HO2S

Yes/No

No

CKP Active Counter

ID

Counts

Varies

CKP Resync Counter

ID

Counts

0

CKP Sensor

ED, ID

RPM

Varies

CMP Active Counter

CMP, ID

1-250

9-250

CMP Sensor

CMP, ID, MF

RPM

Varies

Cold Start-Up

ED, EVAP, FT

Yes/No

Varies

Cruise Control Active

ED

Yes/No

No

Cycles of Misfire Data

MF

0-100 Counts

Varies

Decel Fuel Cutoff

ED, FT, HD, HO2S

Active/Inactive

Inactive

Desired Exh. CMP

CMP

Degrees

--

Desired Amp Voltage

HD

Volts

14 Volts

Desired Hybrid Battery Soc

ED, HD

%

65-75%

Desired Idle Speed

CMP, ED, EVAP, IND, TAC

RPM

PCM Controlled

Desired Int. CMP

CMP

Degrees

Desired Starter Generator Torque

ED

N·m

8N·m

Distance Since DTC Cleared

ED

km/miles

Varies

EC Ignition Relay Circuit Status

ED

OK/Incomplete/ Short B+/ Short Ground/ Short Open

Incomplete

EC Ignition Relay Command

ED, TAC

ON/OFF

ON

EC Ignition Relay Feedback Signal

ED, TAC

Volts

14 Volts

ECT Sensor

CMP, ED, EVAP, FT, HO2S, ID, IND, MF, TAC

-40 to 151°C (+151 to +303°F)

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

Engine Auto Start Reason

HD

Varies

None

Engine Load

ALL

0-100%

30-24% @ Idle

42% @ 2500 RPM

Engine Oil Pressure Sensor

CMP, MF

psi/kPa

4 kPa

Engine Oil Pressure Switch

CMP, ED,

OK/Low

OK

Engine Oil Temp Calculated

CMP

Degrees

Varies

Engine Run Time

ALL

Hrs, Min, Sec

Varies

Engine Speed

ALL

0-10,000 RPM

500-700 RPM

Engine Time Off

EVAP, HO2S

HH:MM:SS

Varies

EVAP Fault History

EVAP

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

No Fault

EVAP Purge Solenoid Command

ED, EVAP, FT, HO2S

0-100%

10-30%

EVAP Vent Solenoid Command

ED, EVAP

Not Venting/Venting

Venting

Exh. CMP Active Counter

CMP, ID

Counts

0-250

Exh. CMP Angle

CMP

Degrees

Exh. CMP Command

CMP

%

0%

Exh. CMP Variance

CMP

Degrees

Ext, Travel BPP Signal

TAC

Applied/ Released/ Invalid

Invalid

Fuel Level Sensor

EVAP

Volts

1-2 Volts

Fuel Pump Relay Circuit Status

ED

OK/ Incomplete/ Short B+/ Short Ground/ Short Open

Incomplete

Fuel Tank Level Remaining

ED, EVAP, FT, MF

0%

Varies

Fuel Tank Pressure Sensor

ED, EVAP

mm/Hg / In H2O

Varies

Fuel Tank Pressure Sensor

EVAP

Volts

Varies

Fuel Tank Rated Cap.

EVAP

Liters

Varies

Fuel Trim Cell

ED, FT

Counts

16, 17, 21

Fuel Trim Learn

ED, FT

Able/Disable

Disabled

Fuel Pump Relay Command

ED

On/Off

On

Fuel Volatility

EVAP, FT

Low/ Med/ High

Low

HO2S 1

ED, EVAP, FT, HO2S, IND

mV

10-1,000 mV and Varying

HO2S 1 Heater Command

HO2S

%

--

HO2S 1 Heater Command

HO2S

ON/ OFF

ON

HO2S 2

ED, EVAP, FT, HO2S, IND

mV

10-1,000 mV and Varying

HO2S 2 Heater Command

HO2S

%

Varies

HO2S 2 Heater Command

HO2S

ON/ OFF

ON

Hot Open Loop

FT, HO2S

Active/Inactive

Inactive

Hybrid Battery Aug Cell Temp

ED

Degrees

70 Degrees

Hybrid Battery Current

HD

Amps

0.1-1.0 Amps

Hybrid Battery Power Available

ED, HD

Watts

10,000-11,000 Watts

Hybrid Battery Soc

ED, HD

%

70-75%

Hybrid Battery Voltage

ED, HD

Volts

39-40 Volts

IAT Sensor

ALL

-40 to +151°C (-40 to +303°F)

Depends on ambient temperature

Ignition Accessory Signal

ED, TAC

On/Off

ON

Ignition 1 Signal

ALL

0-25 volts

11.5-14.5 Volts

Ignition OFF Time

ED, EVAP

HH:MM:SS

Varies

Injector 1 Disabled Due to Misfire

MF

Yes/ No

No

Injector 2 Disabled Due to Misfire

MF

Yes/ No

No

Injector 3 Disabled Due to Misfire

MF

Yes/ No

No

Injector 4 Disabled Due to Misfire

MF

Yes/ No

No

Int. CMP Active Counter

CMP, ID

Counts

0-250

Int. CMP Angle

CMP

Degrees

0%

Int. CMP Command

CMP

%

0%

Int. CMP Variance

CMP

Degrees

0%

Intake Manifold Pressure

ED, FT, ID

kPa

55-65 kPa

Injector PWM

ED, FT, HO2S, MF

Milliseconds

2-6 ms

Knock Detected Cyl. 1

ID

Yes/No

No

Knock Detected Cyl. 2

ID

Yes/No

No

Knock Detected Cyl. 3

ID

Yes/No

No

Knock Detected Cyl. 4

ID

Yes/No

No

Knock Retard

ID

Degrees

0%

Long Term FT

ED, EVAP, FT, HO2S

%

Near 0%

Loop Status

ED, EVAP, FT, HO2S

Open/Closed

Closed

MAF Sensor

HO2S, IND

Hz

3 g/s

MAF Sensor

ALL

g/s

3-4 g/s

MAP Sensor

ED

Volts

28-35

MAP Sensor

ALL

kPa

20-48 kPa

MIL Command

ED, EVAP, ID

Off/On

Off

MIL Requested By DTC

ALL

Yes/No

No

Misfire Current Cyl #1

MF

Counts

0

Misfire Current Cyl #2

MF

Counts

0

Misfire Current Cyl #3

MF

Counts

0

Misfire Current Cyl #4

MF

Counts

0

Misfire History Cyl #1

MF

Counts

0

Misfire History Cyl #2

MF

Counts

0

Misfire History Cyl #3

MF

Counts

0

Misfire History Cyl #4

MF

Counts

0

PNP Switch

ED, HD

Park/ Net/ In Gear

--

Power Enrichment

ED, FT, HO2S, MF

Active/Inactive

Inactive

Reduced Engine Power

TAC

Active/Inactive

Inactive

Regen Braking Dis Reason

ED, HD

Varies

Varies

Short Term FT

ED, EVAP, FT, HO2S

%

Near 0%

Spark

ED, FT, HO2S, ID, IND, MF

Degrees

11-20°

Start Up ECT

EVAP, HO2S

°C/°F

Varies

Start Up IAT

EVAP

°C/°F

Varies

Starter Generator Belt Slip

ED

%

Near 0%

Starter Generator Mode

HD

Varies

Auto-start

Starter Generator Speed

HD

RPM

1,500-1,700 RPM

TAC Forced Engine Shutdown

TAC

Yes/No

No

TAC Motor

TAC

Enabled/Disabled

Enabled

TAC Motor Command

TAC

%

179%

TCC/Cruise Brake Pedal

TAC

Released/Unreleased

Released

TCS Torque Delivered Signal

TAC

%

0%

TCS Torque Request Signal

TAC

%

100%

TFP Switch

HD

P/N / in gear

P/N

Total Knock Retard

ID

Degrees

0%

Total Misfire Count

MF

Count

0

TP Desired Angle

TAC

%

4%

TP Indicated Angle

ALL

%

6%

TP Sensor 1

TAC

%

4%

TP Sensor 1

TAC

Volts

4.24 Volts

TP Sensor 1 Indicated Position

TAC

%

4%

TP Sensor 1 Learned Minimum

TAC

Volts

0.55 Volts

TP Sensors 1 and 2

TAC

Agree/Disagree

Agree

TP Sensor 2

TAC

%

4%

TP Sensor 2

TAC

Volts

0.75 Volts

TP Sensor 2 Indicated Position

TAC

%

4%

TP Sensor 2 Learned Minimum

TAC

Volts

0.57 Volts

Vehicle Speed Sensor

ALL

km/h (mph)

0

Warm-ups Since DTC Cleared

ED

Counts

Varies

Warm-ups Without Emission Faults

ED

Counts

Varies

Warm-ups Without Non-Emission Faults

ED

Counts

Varies

Wide Open Throttle

TAC

Yes/No

No