GM Service Manual Online
For 1990-2009 cars only

Diagnostic Category

Diagnostic Information

DEFINITION: The following table consists of seven diagnostic categories that are located in the left-hand column. Using this column, choose the appropriate category based on the operating conditions of the vehicle or transmission. After selecting a category, use the right-hand column to locate the specific symptom diagnostic information.

Fluid Diagnosis

This category contains the following topics:

    • Fluid condition - appearance, contaminants, smell, overheating
    • Fluid leaks
    • Refer to Fluid Leak Diagnosis.

Noise and Vibration Diagnosis

This category contains the following topics:

    • Noise - drive gear, final drive, whine, growl, rattle, buzz, popping
    • Vibration

Refer to Torque Converter Diagnosis.

Range Performance Diagnosis

This category contains the following topics:

    • No Park
    • No engine braking
    • Refer to No Park.
    • Refer to No Engine Braking in First Gear.

Shift Quality/Feel Diagnosis

This category contains the following topic:

Harsh shifts

Refer to Harsh Park or Neutral to Drive Engagement.

Torque Converter Diagnosis

This category contains the following topic

Torque Converter Diagnosis

Refer to Torque Converter Diagnosis.

If no symptoms are found.

    • Refer to Transmission Fluid Check.
    • Refer to Road Test.