Customer Complaint Analysis

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

STEP 2: DTC / Freeze Frame Data Check, Record and Clearance

First, check DTC (including pending DTC), referring to DTC Check. If DTC is indicated, print it and freeze frame data or write them down and then clear them by referring to DTC Clearance. DTC indicates malfunction that occurred in the system but does not indicate whether it exists now or it occurred in the past and the normal condition has been restored now. To check which case applies, check the symptom in question according to Step 5 and recheck DTC according to Step 6 and 7. Clearing Diagnostic Trouble Codes Reading Diagnostic Trouble Codes

Attempt to diagnose a trouble based on DTC in this step only or failure to clear the DTC in this step will lead to incorrect diagnosis, trouble diagnosis of a normal circuit or difficulty in troubleshooting.

STEP 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 referring to Visual Inspection.

STEP 5: Trouble Symptom Confirmation

Based on information obtained in Step 1: Customer Complaint Analysis and Step 2: DTC / Freeze Frame Data Check, Record and Clearance, confirm trouble symptoms. Also, reconfirm DTC according to DTC Confirmation Procedure described in each DTC diag. flow.

STEP 6 and 7: Rechecking and Record of DTC / Freeze Frame Data

Refer to DTC Check for checking procedure.

STEP 8: Engine Basic Inspection and Engine Symptom Diagnosis

Perform basic engine check according to Engine Basic Inspection first. When the end of the flow has been reached, check the parts of the system suspected as a possible cause referring to Engine Symptom Diagnosis and based on symptoms appearing on the vehicle (symptoms obtained through steps of customer complaint analysis, trouble symptom confirmation and/or basic engine check) and repair or replace faulty parts, if any.

STEP 9: Troubleshooting for DTC (See each DTC Diag. Flow)

Based on the DTC indicated in Step 6 or 7 and referring to the applicable DTC diag. flow, locate the cause of the trouble, namely in a sensor, switch, wire harness, connector, actuator, ECM or other part and repair or replace faulty parts.

STEP 10: Intermittent Problems Check

Check parts where an intermittent trouble is easy to occur (e.g., wire harness, connector, etc.), referring to Intermittent and Poor Connection Inspection and related circuit of DTC recorded in Step 2.

STEP 11: Final Confirmation Test

Confirm that the problem symptom has gone and the engine is free from any abnormal conditions. If what has been repaired is related to the DTC, clear the DTC once, perform DTC confirmation procedure and confirm that no DTC is indicated.