Engine Diagnostic Flow Chart

Engine 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 an inspection form will facilitate collecting information to the point required for proper analysis and diagnosis.
Customer Problem Inspection Form (Example)

2. DIAGNOSTIC TROUBLE CODE (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 4 and recheck DTC according to Step 5.
Reading Diagnostic Trouble Codes
Clearing 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.

NOTE:
- If only DTC P0461 (Fuel level sensor circuit performance problem) is indicated in this step, perform visual inspection according to Step 3 and then proceed to DTC P0461 Flow Chart.
- If only Automatic transmission DTCs (P0705 to P0758) are indicated in this step, perform trouble diagnosis according to "Diagnosis".

3. 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".
Engine

4. TROUBLE SYMPTOM CONFIRMATION
Based on information obtained in Step 1 Customer complaint analysis and Step 2 DTC/freeze frame data check, confirm trouble symptoms. Also, reconfirm DTC according to "DTC Confirmation Procedure" described in each "DTC FLOW CHART".

5. RECHECKING AND RECORD OF DTC/FREEZE FRAME DATA
Refer to "DTC check" for checking procedure.
Reading Diagnostic Trouble Codes

6. ENGINE BASIC INSPECTION AND SYMPTOMS-TO-DIAGNOSIS MATRIX TABLE
Perform basic engine check according to the "Engine Basic Inspection Flow Chart" first. When the end of the flow chart has been reached, check the parts of the system suspected as a possible cause referring to SYMPTOMS-TO-DIAGNOSIS MATRIX TABLE 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.
Engine
Symptom Related Diagnostic Procedures

7. DIAGNOSTIC TROUBLE CODE FLOW CHART (See each DTC Flow Chart)
Based on the DTC indicated in Step 5 and referring to "DIAGNOSTIC TROUBLE CODE FLOW CHART", 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.
A & B Charts and Tables

8. 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 DTC recorded in step 2. Standard Electrical Circuit Service and Inspection Procedures

9. 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.
Test Result Confirmation Flow Chart