Flow of Diagnosis
SYSTEMATIC TROUBLE SHOOTINGBefore performing troubleshooting for mechanical function described hereafter, make sure to check each of the following.
1. Engine coolant temperature is at normal operating temperature.
2. Engine idle speed is within specification.
3. Transmission fluid level is between FULL HOT and LOW HOT on oil level gauge at normal operating temperature of transmission fluid.
4. Accelerator cable, oil pressure control cable and select cable are adjusted properly.
5. Electric circuit of gear shift control system is free from break, coupler disconnection and poor contact.
AUTOMATIC TRANSMISSION DIAGNOSTIC FLOW TABLE
Refer to the following for the details of each 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 an inspection form will facilitate collecting information to the point required for proper analysis and diagnosis.
Customer Problem Inspection Form (example)
NOTE: The form shown is a standard example. It should be modified according to conditions characteristic of each market.
2. DIAGNOSTIC TROUBLE CODE (DTC)/FREEZE FRAME DATA CHECK, RECORD AND CLEARANCE
First, check for Diagnostic Trouble Codes (including pending DTC). If DTC exists, print or write down DTC and freeze frame data and then clear them.
A 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 4 and then recheck DTC according to Step 5. Diagnosing a trouble based on the DTC in this step only or failure to clear the DTC in this step may result in a faulty diagnosis, trouble diagnosis of a normal circuit or difficulty in troubleshooting which is otherwise unnecessary.
3. and 4. VISUAL INSPECTION
As a preliminary step, be sure to perform visual check of the items that support proper function of the engine and automatic transmission referring to "Visual Inspection".
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, reconfirm Diagnostic Trouble Code (DTC) according to "DTC Confirmation Procedure" described in each "DTC Diag. Flow Table".
6. and 7. RECHECKING AND RECORD OF DTC/FREEZE FRAME DATA
Refer to "DTC Check" for checking procedure.
8. AUTOMATIC TRANSMISSION BASIC CHECK AND SYMPTOM-TO-INSPECTION TABLE
Perform basic check of A/T according to "Basic Check" first. When the end of the flow table has been reached, check the parts of the system suspected as a possible cause referring to "Diagnosis By Symptom" and based on symptoms appearing on the vehicle (symptoms obtained through steps of customer complaint analysis, trouble symptom confirmation and/or the Basic Check) and repair or replace faulty parts, if any.
9. DIAGNOSTIC TROUBLE CODE (DTC) FLOW TABLE (See each DTC Flow Table)
Based on the Diagnostic Trouble Code (DTC) indicated in Step 6 and 7, and referring to "Trouble Code Descriptions", locate the cause of the trouble, namely in a sensor, switch, wire harness, connector, actuator, Powertrain Control Module (PCM) or other part and repair or replace faulty parts.
10. CHECK FOR INTERMITTENT PROBLEM
Check parts where an intermittent trouble is easy to occur (e.g., wire harness, connector, etc.) referring to "Intermittent and Poor Connection" and related circuit of Diagnostic Trouble Code (DTC) recorded in step 2.
11. FINAL CONFIRMATION TEST
Confirm that the problem symptom has gone and the vehicle is free from any abnormal conditions. If what has been repaired is related to the Diagnostic Trouble Code (DTC), clear the DTC once, perform DTC confirmation procedure and check to ensure that no DTC is indicated.