Diagnostic Starting Point - Automatic Transmission

Begin the system diagnosis with Diagnostic System Check - Vehicle . The Diagnostic System Check provides the following information:

• The identification of the control module or modules which commands the system
• The ability of the control module or modules to communicate through the serial data circuit
• The identification and status of stored DTCs

The use of the Diagnostic System Check - Vehicle identifies the correct procedure for diagnosing the system and the procedure location.

Symptoms 

When it has been determined through Diagnostic System Check - Vehicle that no DTCs are present, begin symptom diagnosis by reviewing the Transmission Component and System Description . Reviewing the Transmission Component and System Description information enables you to understand the operation of the system. This helps you determine if the condition described by the customer is normal or if a malfunction exists. If it is determined that a malfunction exists, identify the concern by referring to the table Symptoms - Automatic Transmission . The table Symptoms - Automatic Transmission provides common diagnostic categories which relate directly to diagnostic information or procedures.