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 Engine Controls Diagnostic Check is completed.
    • No diagnostic trouble codes (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.

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.

Eng 1: Eng 1 List

Eng 2: Eng 2 List

FS: FS Data

Engine Scan Tool Data List

Scan Tool Parameter

Data List

Units Displayed

Typical Data Value

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

A/C Request Signal

Eng 1

Yes/No

No

Actual Fuel Rail Pressure

All

MPa/PSI

33-36 MPa (4,786-5,221 PSI)

APP Indicated Angle

All

%

0.0

APP Sensor 1

Eng 1

Volts

0.44-0.95

APP Sensor 2

Eng 1

Volts

3.9-4.5

APP Sensor 3

Eng 1

Volts

3.6-4.1

Balancing Rate Cyl. 1-6

Eng 2

mm³

-2.7 to +2.7

BARO

Eng 1

kPa

Varies with altitude

Basic Fuel Rate

FS

mm³

varies

Battery Voltage

Eng 1

Volts

12-14

Boost Pressure Sensor

Eng 1

kPa/PSI

60-170 kPa

Crank Signal Present

Eng 1

Yes/No

Yes

CAM Signal Present

Eng 1

Yes/No

Yes

Clutch Pedal Switch

Eng 1

Applied/Released

Released

Cruise Control Active

Eng 1

Yes/No

No

Cruise ON/OFF Switch

Eng 1

ON/OFF

OFF

Cruise Resume/Accel Switch

Eng 1

ON/OFF

OFF

Cruise Set/Coast Switch

Eng 1

ON/OFF

OFF

Desired Fan Speed

FS

RPM

450-500

Desired Fuel Rail Pressure

All

MPa/PSI

33-36 MPa (4,786-5,221 PSI)

Desired Idle Speed

Eng 1

RPM

630-700

DTC Set This Ignition

Eng 1

Yes/No

No

ECT Sensor

Eng 1, FS

°C/ °F

85-105°C /185-220°F

Engine Oil Level Switch

Eng 1

OK/Low

OK

Engine Oil Life Remaining

Eng 1

%

0-100

Engine Run Time

All

Hrs/Mins/Sec

Varies with engine run time

Engine Speed

All

RPM

630-700

Exhaust Brake Relay Command

Eng 1

ON/OFF

OFF

Exhaust Brake Switch

Eng 1

ON/OFF

OFF

Fan Speed (with fan control)

FS

RPM

630-700

Final Fuel Rate

All

mm³

varies

Fuel Level Sensor

FS

%

0-100

Fuel Rate at Start

FS

mm³

varies

Fuel Rate Correction

FS

mm³

varies

Fuel Temperature Sensor

All

°C/°F

10-90°C/50-194°F

GEN L-Terminal Signal

Eng 1

Voltage/No Voltage

Voltage

Glow Plug Relay

Eng 1

ON/OFF

OFF

High Idle Switch

Eng 1

ON/OFF

OFF

IAT Sensor

Eng 1

°C/°F

10-90°C/50-194°F

Ignition 1 Signal

Eng 1

Volts

12-14

Injector 1-6 Command

Eng 2

ms

0.7-0.9

Intake Air Heater Relay Command

Eng 1

ON/OFF

OFF

Low Coolant Level

Eng 1

Yes/No

No

Main Injection Timing

Eng 1, Eng 2, FS

degrees

1-1.5

MIL Command

Eng 1

ON/OFF

OFF

PCM Reset

Eng 1

Yes/No

No

PNP Switch

Eng 1

Applied/Released

Released

Power Relay Status

Eng 1

ON/OFF

OFF

PTO Enable

Eng 1

Yes/No

No

PTO Engage Relay Command

Eng 1

ON/OFF

OFF

PTO Engine Shutdown Signal

Eng 1

Yes/No

No

PTO Feedback Signal

Eng 1

Relay ON/Relay OFF

Relay OFF

Reverse Enable

Eng 1

Yes/No

No

Starter Relay Command

Eng 1

ON/OFF

OFF

Start up ECT

Eng 1

°C/°F

Varies

Stop Lamp Pedal Switch

Eng 1

Applied/Released

Released

Two Speed Axle Switch

Eng 1

ON/OFF

OFF

Vehicle Speed Sensor

Eng 1, FS

mph/km/h

0

Wait To Start

Eng 1

ON/OFF

OFF