GM Service Manual Online
For 1990-2009 cars only

The Engine Scan Tool Data List contains all of the engine related parameters that are available on the scan tool. The list is arranged in alphabetical order.

Use the Engine Scan Tool Data List only after verifying the following:

    • The Diagnostic System Check-Engine Controls is completed.
    • No diagnostic trouble codes (DTCs) are present.
    • The 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 normally running engine.

Important: A scan tool that displays faulty data should not be used. The scan tool problem should be reported to the manufacturer. The 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.

Scan Tool Parameter

Data List

Units Displayed

Typical Data Value

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

AC Relay Command

Engine Data

On/Off

Off

AC Request Signal

Engine Data

Yes/No

No

Cam Phase Angle Actual

Camshaft Phase Data

Degrees

Cam Phase Angle Desired

Camshaft Phase Data

Degrees

Cam Phase Angle Variance

Camshaft Phase Data

Degrees

Camshaft Phase Solenoid DC

Camshaft Phase Data

Percent

30-40%

Camshaft Phase Solenoid Command

Engine Data

Active/Inactive

Active

Decel Fuel Cutoff

Engine Data

Active/Inactive

Inactive

Diagnostic Mode

Engine Data

Normal/Check

Normal

ECT Sensor

Engine Data

°C (°F)

80-90°C (176-194°F)

Engine Load

Engine Data

Percent

14-30%

Engine Speed

Engine Data

RPM

650-750 RPM

Engine Speed at Misfire

Misfire Data

RPM

0 RPM

EVAP Purge Solenoid

EVAP Data

On/Off

Off

Fuel Pump Relay Command

Engine Data

On/Off

On

Fuel Tank Pressure Sensor

EVAP Data

mm Hg/in H2O

Varies

High Electrical Load

Engine Data

Yes/No

No

HO2S 1

Engine Data

mV

Varies

HO2S 1 L/R Response Time

Engine Data

ms

0-1000 ms

HO2S 1 R/L Response Time

Engine Data

ms

0-1000 ms

HO2S 2

Engine Data

mV

Varies

IAC Motor Command

Engine Data

Percent

27-47%

IAT Sensor

Engine Data

°C (°F)

Varies with underhood and ambient air temperatures

Ign. Cycle Counter

Engine Data

Counts

0-400 Counts

Injector 1 Command

Engine Data

ms

1.90-2.25 ms

Load at Misfire

Misfire Data

G/Rev

0.00 G/Rev

Long Term FT

Engine Data

Percent

-20% to +20%

Loop Status

Engine Data

Open/Closed

Closed

MAF Sensor

Engine Data

g/s

1.75-2.10 g/s

MIL Command

Engine Data

On/Off

Off

Misfire Current Cyl #1

Misfire Data

Counts

0

Misfire Current Cyl #2

Misfire Data

Counts

0

Misfire Current Cyl #3

Misfire Data

Counts

0

Misfire Current Cyl #4

Misfire Data

Counts

0

Number of DTCs

Engine Data

Varies

0

PNP Switch

Engine Data

Park/Neutral or In Gear

Park/Neutral

Short Term FT

Engine Data

Percent

-20% to +20%

Spark

Engine Data

Degrees

8-18°

Starter Switch

Engine Data

Released/Cranking

Released

TCC Brake Pedal Switch

Engine Data

Released/Applied

Released

TCC Enable Solenoid Command

Engine Data

On/Off

Off

Total Fuel Trim Average

Engine Data

Counts

0.25-0.75 (varies)

Total Misfire Current Count

Misfire Data

Counts

0

TP Sensor

Engine Data

Percent

8-11%

Vehicle Speed Sensor

Engine Data

km/h/mph

0 km/h

4-spd Automatic Transmission Equipped Vehicles Only