Diagnostic Starting Point - Automatic Transmission

LCT 1000 Allison Transmission

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 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 diagnostic trouble codes (DTCs)

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

Symptoms
When it has been determined through Diagnostic System Check - Vehicle that no DTCs are present, begin symptom diagnosis by reviewing the Functional Test Procedure. 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 Symptoms - Automatic Transmission. The Symptoms - Automatic Transmission provides common diagnostic categories which relate directly to diagnostic information or procedures.