Symptoms - Automatic Transmission

Automatic Transmission - 10L80 MHS MQC | Diagnostic Information and Procedures | Document ID: 4567898

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

Note

Perform electrical function test first in order to ensure the electronic transmission components are functioning properly. If these components are not checked, a simple electrical condition could be misdiagnosed. – Road Test – Transmission Fluid Level and Condition Check – Automatic Transmission Fluid Leaks – Fluid Leak Diagnosis Noise and Vibration Diagnosis – Whine/Growl Noise That Changes with Vehicle Speed – Vibration – Flex Plate/Torque Converter Vibration Test – Noise and Vibration Analysis Range Performance Diagnosis – No Park or Drive – No Drive in All Ranges Shift Quality Feel Diagnosis – Harsh Garage Shift – Harsh, Soft, Delayed or Slipping First, Second, Third, Fourth, Fifth, Sixth, or Reverse Shift – Harsh, Soft, Delayed or Slipping First, Second, Eighth, Ninth, Tenth, or Reverse Shift – Harsh, Soft, Delayed or Slipping Second, Third, Fourth, Fifth, Seventh, Ninth, or Tenth Shift – Harsh, Soft, Delayed or Slipping First, Second, Third, Fourth, Sixth, Seventh, Eighth, Tenth, or Reverse Shift – Harsh, Soft, Delayed or Slipping First, Third, Fifth, Sixth, Seventh, Eighth, or Ninth Shift – Harsh, Soft, Delayed or Slipping Fourth, Fifth, Sixth, Seventh, Eighth, Ninth, Tenth, or Reverse Shift Shift Pattern – No First, Second, Third, Fourth, Fifth, Sixth, or Reverse Gear – No First, Second, Eighth, Ninth, Tenth, or Reverse Shift Gear – No Second, Third, Fourth, Fifth, Seventh, Ninth, or Tenth Gear – No First, Second, Third, Fourth, Sixth, Seventh, Eighth, Tenth, or Reverse Gear – No First, Third, Fifth, Sixth, Seventh, Eighth, or Ninth Gear – No Fourth, Fifth, Sixth, Seventh, Eighth, Ninth, Tenth, or Reverse Gear Torque Converter Diagnosis – Torque Converter Diagnosis – No Torque Converter Clutch Apply – No Torque Converter Clutch Release Symptom Not Found or No Symptom Detected – Road Test – Transmission Fluid Level and Condition Check