Engine and Emission Control System Check
Engine and Emission Control System CheckStep 1-6:
Step 7-11:
Numbers of each step correspond to the numbers of the items after this table. Refer to the following items for the detail of each step.
Description for 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 an inspection form will facilitate collecting information to the point required for proper analysis and diagnosis.
NOTE: The form is standard sample. It should be modified according to conditions and characteristics of each market.
Customer problem inspection form (Example)
STEP 2: DTC / freeze frame data check, record and clearance
First, check DTC (including pending DTC), referring to DTC Check. If DTC is indicated, record DTC and freeze frame data. After that clear DTC 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.
Attempt to diagnose a trouble based on DTC in this step only or failure to clear the DTC (including pending DTC) in this step will lead to incorrect diagnosis, trouble diagnosis of a normal circuit or difficulty in troubleshooting.
NOTE: If any DTC P0461 (Fuel level sensor circuit range / performance problem) is indicated in this step, perform visual inspection according to Step 3 and then proceed to DTC P0461: Fuel Level Sensor Circuit Performance.
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 => "Customer complaint analysis" and => "DTC / freeze frame data check" , confirm trouble symptoms. Also, reconfirm "DTC according to DTC Confirmation Procedure" described in each diag. flow.
STEP 6 and 7: DTC / freeze frame data check
Refer to DTC Check or checking procedure.
STEP 8: Engine basic inspection and engine symptom diagnosis
Perform basic engine check according to the Engine Basic Check 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: DTC troubleshooting
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 malfunction DTC (a normal code) is indicated.