Automatic Transmission Diagnostic Flow Chart
DIAGNOSISThis vehicle is equipped with an electronic transmission control system, which controls the automatic shift up and shift down timing, Torque Converter Clutch (TCC) operation, etc. suitably to vehicle driving conditions.
When diagnosing a trouble in the transmission including this system, follow "AUTOMATIC TRANSMISSION DIAGNOSTIC FLOW CHART" given to obtain correct result smoothly.
AUTOMATIC TRANSMISSION DIAGNOSTIC FLOW CHART
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 questionnaire form as shown will facilitate collecting information to the point required for proper analysis and diagnosis.
CUSTOMER QUESTIONNAIRE (ENGINE)
NOTE: The above form is a standard sample. It should be modified according to conditions characteristic of each market.
2. DIAGNOSTIC TROUBLE CODE (DTC) CHECK, RECORD AND CLEAR
DTCs are indicated by the malfunction indicator lamp ("O/D OFF" light). When a DTC is indicated by this lamp, it means existence of a malfunction in the system represented by that code but whether is still exists (current) or it occurred in the past and has gone (history) is unknown. To know it, clear this DTC once , perform Step 6 TEST DRIVE and/or PROBLEM SYMPTOM of AUTOMATIC TRANSMISSION DIAGNOSTIC FLOW CHART and then check DTC again as described. Attempt to diagnose the trouble based on the DTC recorded in this step or failure to clear the DTC in this step may mislead the diagnosis or make diagnosing difficult. Even after checking the DTC with the Tech-1, diagnosis should be performed according to this flow chart to check TCM for proper self-diagnosis function.
3. VISUAL INSPECTION
As a preliminary step, perform visual check of the following items that support proper function of the automatic transmission.
4. PROBLEM SYMPTOM CONFIRMATION
Check if what the customer claimed in Step 1 is actually found in the vehicle and if that symptom is found, whether it is identified as a failure. (This step should be shared with the customer if possible.) When the symptom is not actually found, possibility is:
- The symptom occurs under certain conditions.
- Retry with the vehicle under different conditions.
- The trouble occurred only temporarily and normal operation has been restored.
- Perform Step 3 and if the diagnostic trouble code is indicated, inspect according to the flow chart for that DTC.
5. AUTOMATIC TRANSMISSION BASIC CHECK
Perform basic automatic transmission check according to the flow below first.
AUTOMATIC TRANSMISSION BASIC CHECK FLOW CHART
5-1. DIAGNOSTIC TROUBLE CODE CHECK
Check diagnostic trouble code, referring diagnostic trouble code(s) check.
5-2. DIAGNOSTIC TROUBLE CODE FLOW CHART
Based on the DTC indicated in Step 5-1 and referring to DIAGNOSTIC TROUBLE CODE FLOW CHART, locate the cause of the trouble, namely in a sensor, switch, wire harness, connector, actuator, Transmission Control Module (TCM) or other part and repair or replace faulty parts.
6. FINAL CONFIRMATION TEST
Confirm that the problem symptom has gone and the automatic transmission is free from any abnormal conditions. If what has been repaired is related to the malfunction DTC, clear the DTC once and perform test driving and confirm that a normal code is indicated.