GM Service Manual Online
For 1990-2009 cars only

Refer to the data tables when one of the following conditions exist:

    • The Instrument Panel Cluster (IPC) System Check is complete.
    • The on board diagnostics are operating correctly.
    • No diagnostic trouble codes (DTCs) are displayed.

The typical scan tools data values are an average of the displayed values recorded from normally operating vehicles. The typical scan tools data values represent the displayed values of a normally functioning system with certain preliminary settings. The values received may vary slightly due to a low battery charge or other reasons. The values should be very close.

Use only the parameters listed in the tables for diagnosis. If a scan tool reads other parameters the values are not recommended for use in diagnosis.

Refer to the applicable DTC table for more information on the following items:

    • Scan tool typical data values
    • The use of a scan tool in order to diagnose the IPC

If all of the values are within the specified range, refer to the Instrument Cluster System Check.

Typical Scan Tool Data Display

Set the following preliminary settings in order to achieve the same typical data values listed in the table:

    • The parking brake is set with the ignition in the OFF position (DRL and AHL disabled).
    • The ignition is in the RUN position.
    • The engine is running.
    • The upper radiator hose is hot.
    • The loop is closed.
    • The automatic transmission is in the PARK position.
    • The manual transmission is in the NEUTRAL position.
    • The air conditioning is OFF.

Scan Tool Parameter

Data List

Units Displayed

Typical Data Value

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

Important: All of the IPC LEDs outputs are not listed. The IPC LEDs not listed are controlled by a different device. Refer to the applicable device when diagnosing IPC LEDs not shown in the table below.

ABS Lamp

Output

ON/OFF

OFF

Battery

Output

ON/OFF

OFF

Battery Voltage

Data

Volts

12.0-14.7 Volts (Varies with the vehicle)

Brake Lamp

Output

ON/OFF

ON

Check Gauges Lamp

Output

ON/OFF

OFF

Dimming

Input

Active/Inactive

Active (when the Park Lamps are ON)

Displayed Coolant Temperature

Data

Degrees Fahrenheit (°C)

190°F (87°C)

Displayed Fuel Level

Data

Percentage (%)

0-100% (Varies with the fuel tank level)

Displayed Odometer Mile

Data

Miles

XXX,XXX Miles (Varies with the mileage of the vehicle)

Displayed Trip Odometer

Data

Miles

XXX,XXX Miles (Varies with the mileage of the vehicle

Engine Speed

Data

Revolutions Per Minute (RPM)

500-700 RPM (Varies with the vehicle)

Fasten Seat Belts

Output

ON/OFF

ON

High Beam Lamp

Output

ON/OFF

OFF

Low Fuel Lamp

Output

ON/OFF

OFF

Monitored Coolant Temperature

Data

Degrees Fahrenheit (°F)

190°F (Fluctuates range 180-200°F)

87°C (Fluctuates range 82-93°C)

Monitored Fuel Level

Data

Percentage (%)

0-100% (Varies with the fuel tank level)

Overspeed Lamp

Output

ON/OFF

OFF

Park Switch

Input

Open/Closed

Closed

PRNDL State

Input

Park/ Reverse/ Neutral/ Drive/ Third/ Second/ First/ Invalid

Park

Rear Gate/Door

Output

OPEN/CLOSED

CLOSED

Security Lamp

Output

ON/OFF

OFF

Service 4WD

Output

ON/OFF

OFF

Trip Reset Switch

Input

Active/Inactive

Inactive

Upshift Lamp

Output

ON/OFF

OFF

Vehicle Speed

Data

Miles Per Hour (mph)

0 mph