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 the order shown on the scan tool.

Use the Engine Scan Tool Data List only after performing the following inspections:

    • Powertrain On-Board Diagnostic System Check is completed.
    • No diagnostic trouble codes (DTCs) are present.
    • On-board diagnostics are functioning properly.

Use the scan tool data values from a properly running engine for comparison with the engine that is being diagnosed. The Engine Scan Tool Data List represents values that would be seen on a properly 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.

The scan tool data parameters listed below are the only parameters referenced in this service manual for use in diagnosis. If all scan tool data values are within the typical ranges described below, refer to Symptoms for additional diagnosis.

Scan Tool Parameter

Data List

Units Displayed

Typical Data Value

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

Engine Speed

Engine Data

RPM

800-900 RPM

Desired Idle Speed

Engine Data

RPM

850 RPM

ECT

Engine Data

°C (°F)

80°C to 100°C (176°F to 212°F)

IAT

Engine Data

°C (°F)

Varies with underhood and ambient air temperatures

Engine Load

Engine Data

%

3-5%

MAP

Engine Data

kPa

29 to 47 kPa

MAP

Engine Data

Volts

1.32-1.90 Volts (varies with vacuum and barometer and altitude)

BARO

Engine Data

kPa

89 to 99 kPa (varies with vacuum and barometer and altitude)

TP Sensor

Engine Data

Volts

0.42-1.15 Volts

TP Angle

Engine Data

%

7-18%

ISC Duty Cycle

Engine Data

%

20-40%

Closed Throttle Switch

Engine Data

Idle/Not Idle

Idle

HO2S 1

Engine Data

mV

50 to 950 mV (varies)

HO2S 2

Engine Data

mV

50 to 950 mV (varies)

Loop Status

Engine Data

Open/Closed Loop

Closed Loop

HO2S 1 Ready

Engine Data

Yes/No

Yes

HO2S 2 Ready

Engine Data

Yes/No

varies

Short Term FT

Engine Data

%

-20% to +20% (varies)

Short Term FT

Engine Data

Counts

128 Counts (varies)

Long Term FT

Engine Data

%

-15% to +15% (varies)

Long Term FT

Engine Data

Counts

128 Counts (varies)

Total Fuel Trim

Engine Data

%

-35% to +35% (varies)

Injector PWM

Engine Data

ms

0.8-2.3 ms

Fuel Cutoff Signal

Engine Data

Yes/No

No

Spark

Engine Data

°

-1° to 18°

Spark Advance Adjust Test Switch

Engine Data

On/Off

Off

EVAP Duty Cycle

Engine Data

%

0-100%

EVAP Vent Solenoid

Engine Data

On/Off

Off (solenoid is OFF with engine coolant temp. below 80°C)

EVAP Density Trim

Engine Data

Counts

0 to 14 Counts (varies)

Fuel Level

Engine Data

%

Varies with the amount of fuel in the tank (90% with a full tank)

Fuel Tank Pressure

Engine Data

mmHg/in H2O

0.0 mmHg (with fuel filler cap removed)

EVAP Tank Pressure Control Solenoid

Engine Data

On/Off

varies

EGR Sol. Vacuum Valve

Engine Data

On/Off

Off

EGR Bypass Solenoid

Engine Data

On/Off

Off

Air Conditioning

Engine Data

On/Off

Off

Engine Coolant Fan

Engine Data

On/Off

Varies with engine coolant temperature

Fuel Pump

Engine Data

On/Off

On

Starter Switch

Engine Data

Released/Cranking

Released

Battery Voltage

Engine Data

Volts

12-14 Volts

Electrical Load Signal

Engine Data

Yes/No

No (with all of the electrical accessories turned Off)

Vehicle Speed

Engine Data

km/h / MPH

0 km/h / 0 MPH