GM Service Manual Online
For 1990-2009 cars only

Note: Use the symptom tables only if the following conditions are met:

   • Refer to Diagnostic Starting Point - Vehicle.
   • There are no DTCs set.
   • The control modules can communicate via the serial data link.
   • Review the system operation in order to familiarize yourself with the system functions. Refer to Transmission General Description and Transmission Component and System Description.

Visual/Physical Inspection

Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom.

Intermittent

Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to Testing for Intermittent Conditions and Poor Connections.

Symptom List

Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom:

    • Fluid Diagnosis
       -  Transmission Fluid Check
       -  Main Fluid Pump Pressure High or Low
       -  Auxiliary Fluid Pump Pressure High or Low
       -  Automatic Transmission Fluid Leaks
       -  Fluid Leak Diagnosis
    • Noise and Vibration Diagnosis
       -  Whine/Growl Noise That Changes with Vehicle Speed
       -  Noise in First or Reverse Gear
       -  Noise in First, Second, Third, Fourth, or Reverse Gear
       -  Noise in First, Second, or Reverse Gear
       -  Noise in Fourth Gear
       -  Vibration
       -  Noise and Vibration Analysis
    • Range Performance Diagnosis
       -  No Park or Drive
       -  No Drive in All Ranges
       -  No Reverse Gear
       -  No Drive or Reverse Gear
    • Shift Quality Feel Diagnosis
       -  Harsh Garage Shift
       -  Harsh, Soft, Delayed or Slipping First or Reverse Gear
       -  Harsh, Soft, Delayed or Slipping 1-2-3-4 Shift
       -  Harsh, Soft, Delayed, or Slipping Reverse Gear
    • Shift Pattern
       -  No First Gear
       -  No First and Reverse Gears
       -  No First, Second, Third, or Fourth Gear
       -  No First, Second, or Reverse Gear
       -  Stuck in First or Reverse Gear
    • Symptom Not Found or No Symptom Detected
       -  Transmission Fluid Check
       -  Road Test
       -  Line Pressure Check