GM Service Manual Online
For 1990-2009 cars only

This Typical Scan Tool Data Values table contains all engine related parameters that are available on the scan tool. The list is 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 Typical Scan Tool Data Values table only after the following is determined:

    • The Powertrain or Transmission On-Board Diagnostic System Check is completed.
    • No Diagnostic Trouble Codes (DTCs) are set.
    • The on-board diagnostics are functioning properly.

Important: Do not use a scan tool that displays faulty data. Report the scan tool problem to the manufacturer. Use of a faulty scan tool can result in misdiagnosis and unnecessary parts replacement.

Scan tool values from a properly operating vehicle may be used for comparison with the vehicle you are diagnosing. The Typical Scan Tool Data Values table represents values that would be seen on a normally operating vehicle.

Only the parameters listed below are in this service manual for use in diagnosis. For further information on using the scan tool in order to diagnose the TCM and related components, refer to the applicable reference section listed below. If all values are within the typical range described below, refer to Symptoms for diagnosis.

The Data List column 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 information is a description of each term listed:

    • Eng 1 = Engine 1 Data List
    • Misfire = Misfire Data List
    • FF = Freeze Frame Data List

For Cold Key On, Cold Idle and Hot Idle: Vehicle in Park, A/C turned Off, no power steering load, all accessories Off, brake pedal Released. For 55 MPH Cruise: Vehicle in Drive 4, A/C turned On and no power steering load. Compare data after driving approximately 1 mile.

Scan Tool Parameter

Units Displayed

Data List

Cold Key On

Cold Idle

Hot Idle

55 MPH Cruise

A/C Clutch Relay

ON/ OFF

Eng 1

OFF

OFF

OFF

ON

AIR Pump Relay

ON / OFF

Eng 1

OFF

ON

OFF

OFF

AIR Solenoid

ON / OFF

Eng 1

OFF

ON

OFF

OFF

APP Sensor 1

Volts

Eng 1

0.2-0.4 V

0.4 V or less

0.4 V or less

Less than 2.5 V

APP Sensor 2

Volts

Eng 1

0.2 V or less

0.2 V

0.2 V

Less than 1.25 V

Base PW

ms

Eng 1

0

3.75 ms

3.5 ms

4.82 ms

Battery Voltage

Volts

Eng 1

B+

B+

B+

B+

Calc. Full Pos. Switch

Active/Inactive

Eng 1

Inactive

Inactive

Inactive

Inactive

Calc. Idle Pos. Switch

Active/Inactive

Eng 1

Active

Active

Active

Inactive

Catalyst Monitor

Yes / No

Eng 1

No

No

No

No

Cruise Release Brake Switch

Applied / Released

Eng 1

Released

Released

Released

Released

Cruise Switch

ON / OFF

Eng 1

OFF

OFF

OFF

OFF

Desired Idle Speed

RPM

Eng 1

920

700-1200

--

--

Driving Cycle Comp.

Yes/No

Eng 1

No

No

Yes

Yes

DTC #1

DTC Number

Eng 1

0000

0000

0000

0000

DTC #2

DTC Number

Eng 1

0000

0000

0000

0000

ECT

°C (°F)

Eng 1

Close to outside air temperature

-20 - 50°C (-4-122°F)

90 - 110°C (194-280°F)

90 - 110°C (194-280°F)

Engine Load

%

Eng 1

--

2-3

2-3

10-12

Engine Power Relay

On/Off

Eng 1

On

On

On

On

Engine Run Time

Hr/min/sec

Eng 1

00:00:00

Varies

Varies

Varies

Engine Speed

RPM

Eng 1

0

700-1200

550-800

2080

EVAP Canister Purge

%

Eng 1

0-5 %

0

Varies

Varies

EVAP Vent Solenoid

On / Off

Eng 1

Off

Off

Off

Off

Fuel Level

Liters

Eng 1

Varies with fuel level

Varies with fuel level

Varies with fuel level

Varies with fuel level

Fuel Level

Volts

Eng 1

Varies with fuel level

Varies with fuel level

Varies with fuel level

Varies with fuel level

Fuel Pump Relay

ON/OFF

Eng 1

OFF after 2 seconds

ON

ON

ON

Fuel Tank Pressure

mm Hg/ in. H2O

Eng 1

Varies

Varies

Varies

Varies

Fuel Tank Pressure

Volts

Eng 1

Varies

Varies

Varies

Varies

HO2S Bank 1 Sensor 1

Lambda

Eng 1

Open

1.0

1.0

1.0

HO2S Bank 1 Sensor 2

mv

Eng 1

465 mv

Varies

Varies

Varies

HO2S Bank 2 Sensor 1

Lambda

Eng 1

Open

1.0

1.0

1.0

HO2S Bank 2 Sensor 2

mv

Eng 1

465 mv

Varies

Varies

Varies

HO2S Bn 1 and Bn 2 Ready

No/Yes

Eng 1

No

No /Yes

Yes

Yes

HO2S Heater Bank 1 Sensor 1

High /Low

Eng 1

Low

Varies

Varies

Varies

HO2S Heater Bank 1 Sensor 2

High /Low

Eng 1

Low

Varies

High

High

HO2S Heater Bank 2 Sensor 1

High /Low

Eng 1

Low

Varies

Varies

Varies

HO2S Heater Bank 2 Sensor 2

High /Low

Eng 1

Low

Varies

High

High

IAT

°C (°F)

Eng 1

Close to Ambient Temperature

Close to Ambient Temperature

Close to Ambient Temperature

Close to Ambient Temperature

Ignition 1 On

Yes/No

Eng 1

Yes

Yes

Yes

Yes

Intake Plenum Switchover Valve

Open/Closed

Eng 1

Open

Open

Open

Open

Intake Reson. Tune Valve

Open/Closed

Eng 1

Closed

Closed

Closed

Closed

Knock Retard Cyl. #1-6

Degrees

Eng 1

0.0

0.0

0.0

0.0

Knock Sensor 1

Active/Inactive

Eng 1

Inactive

Inactive

Inactive

Inactive

Knock Sensor 2

Active/Inactive

Eng 1

Inactive

Inactive

Inactive

Inactive

Long Term FT Bank 1

%

Eng 1

0

Varies

Varies

Varies

Long Term FT Bank 2

%

Eng 1

0

Varies

Varies

Varies

Loop Status Bn 1 Sen. 1

Open/Closed

Eng 1

Open

Open

Closed

Closed

Loop Status Bn 1 Sen. 2

Open/Closed

Eng 1

Open

Open

Closed

Closed

Loop Status Bn 2 Sen. 1

Open/Closed

Eng 1

Open

Open

Closed

Closed

Loop Status Bn 2 Sen. 2

Open/Closed

Eng 1

Open

Open

Closed

Closed

MAF

g/s

Eng 1

0

5-6

4-6

20-24

MIL

On/Off

Eng 1

On

Off

Off

Off

MIL Flashing

Yes/No

Eng 1

No

No

No

No

MIL Request

Yes/No

Eng 1

No

No

No

No

Mileage Since DTC Cleared

Miles

Eng 1

Varies

Varies

Varies

Varies

Misfire Current Cyl #1

Counts

Misfire

0

0

0

0

Misfire Current Cyl #2

Counts

Misfire

0

0

0

0

Misfire Current Cyl #3

Counts

Misfire

0

0

0

0

Misfire Current Cyl #4

Counts

Misfire

0

0

0

0

Misfire Current Cyl #5

Counts

Misfire

0

0

0

0

Misfire Current Cyl #6

Counts

Misfire

0

0

0

0

Misfire History Cyl #1

Counts

Misfire

0

0

0

0

Misfire History Cyl #2

Counts

Misfire

0

0

0

0

Misfire History Cyl #3

Counts

Misfire

0

0

0

0

Misfire History Cyl #4

Counts

Misfire

0

0

0

0

Misfire History Cyl #5

Counts

Misfire

0

0

0

0

Misfire History Cyl #6

Counts

Misfire

0

0

0

0

Number of DTCs

Counts

Eng 1

0

0

0

0

Park/Neutral Switch

P-N/R-D-L

Eng 1

P-N

P-N

P-N

R-D-L

Resume Switch

ON / OFF

Eng 1

OFF

OFF

OFF

OFF

Sec AIR System Ready

No/Yes

Eng 1

No

Yes

No

Varies

Set Switch

ON / OFF

Eng 1

OFF

OFF

OFF

OFF

Short Term FT Bank 1

%

Eng 1

0

0-Varies

Varies

Varies

Short Term FT Bank 2

%

Eng 1

0

0-Varies

Varies

Varies

Spark

Degrees

Eng 1

0

Varies

Varies

Varies

Stoplamp Brake Switch Input

Applied/Released

Eng 1

Released

Released

Released

Released

TAC Learn Counter

Counts

Eng 1

9

0

0

0

Theft Deterrent Status

Correct Code/Incorrect Code/No Immobilizer

Eng 1

Correct code

Correct code

Correct code

Correct code

TP Angle

%

Eng 1

0-3

0-3

0-3

Varies with load

TP Sensor 1

Volts

Eng 1

Less than 0.80 V

Less than 0.80 V

Less than 0.80 V

3.0 V

TP Sensor 2

Volts

Eng 1

More than 4.0 V

More than 4.0 V

More than 4.0 V

About 1.5 V

Vehicle Speed

km/h/mph

Eng 1

0

0

0

55

Warm-Up Cycle Comp.

Yes/No

Eng 1

No

No

Yes

Yes