For 1990-2009 cars

Begin the system diagnosis with Diagnostic Starting Point - Engine Controls in Engine Controls. The Diagnostic System Check provides the following information:

• | The identification of the control modules which commands the system

• | The ability of the control modules to communicate through the serial data circuit

• | The identification and status of stored diagnostic trouble codes (DTCs)

The use of the Diagnostic Starting Point - Engine Controls in Engine Controls identifies the correct procedure for diagnosing the system and the procedure location.

#### Symptoms

When it has been determined through Diagnostic Starting Point - Engine Controls in Engine Controls that no DTCs are present, identify the concern by referring to the Symptoms - Automatic Transmission . The Symptoms - Automatic Transmission table provides common diagnostic categories which relate directly to diagnostic information or procedures.