Automatic Transmission Diagnostic Flow Table

AUTOMATIC TRANSMISSION DIAGNOSTIC FLOW TABLE








Refer to the following for the details of each step.

STEP 1. CUSTOMER COMPLAINT ANALYSIS
Record details of the problem (failure, complaint) and how it occurred as described by the customer. For this purpose, use of such a inspection form will facilitate collecting information to the point required for proper analysis and diagnosis.

STEP 2. DIAGNOSTIC TROUBLE CODE (DTC FREEZE FRAME DATA CHECK, RECORD AND CLEARANCE
First, referring to "How to Display and Read Diagnostic Trouble Codes", check DTC (including pending DTC). If DTC exists, print or write down DTC and freeze frame data and then clear them by referring to DTC clearance. DTC indicates malfunction in the system but it is not possible to know from it whether the malfunction is occurring now or it occurred in the past and normal condition has been restored. In order to know that, check symptom in question according to Step 5 and then recheck DTC according to Step 6.
Diagnosing a trouble based on the DTC in this step only or failure to clear the DTC in this step may result in an faulty diagnosis, trouble diagnosis of a normal circuit or difficulty in troubleshooting which is otherwise unnecessary.

STEP 3 and STEP 4. VISUAL INSPECTION
As a preliminary step, be sure to perform visual check of the items that support proper function of the A/T and engine.

STEP 5. TROUBLE SYMPTOM CONFIRMATION
Check trouble symptoms based on information obtained in Step 1 "CUSTOMER COMPLAINT ANALYSIS" and Step 2 "DTC/FREEZE FRAME DATA CHECK".
Also, recheck DTC according to "DTC CONFIRMATION PROCEDURE" described in each "Trouble Code Diagnostic Procedure".

STEP 6 and STEP 7. RECHECKING AND RECORD OF DTC/FREEZE FRAME DATA
Refer to "How to Display and Read Diagnostic Trouble Codes" for checking procedure.

STEP 8. A/T BASIC CHECK AND TROUBLE DIAGNOSIS TABLE
Perform A/T basic check according to the "A/T Basic Check Flow Table" first. When the end of the flow table has been reached, check the parts of the system suspected as a possible cause and based on symptoms appearing on the vehicle (symptoms obtained through steps of customer complaint analysis, trouble symptom confirmation and/or A/T basic check) and repair or replace faulty parts, if any.

STEP 9. DIAGNOSTIC TROUBLE CODE FLOW TABLE
Based on the DTC indicated in Step 6 and 7, locate the cause of the trouble, namely in a sensor, switch, wire harness, connector, actuator, PCM or other part and repair or replace faulty parts.

STEP 10. CHECK FOR INTERMITTENT PROBLEM
Check parts where an intermittent trouble is easy to occur (e.g., wire harness, connector, etc.) and related circuit of DTC recorded in Step 2.

STEP 11. FINAL CONFIRMATION TEST
Confirm that the problem symptom has gone and the A/T is free from any abnormal conditions. If what has been repaired is related to the malfunction DTC, clear the DTC once, set conditions under which DTC was detected and A/T and/or vehicle was repaired and confirm that no DTC is indicated.

CUSTOMER PROBLEM INSPECTION FORM (EXAMPLE)





NOTE: The form is a standard sample. It should be modified according to conditions characteristic of each market.