(1) Carry out a test drive with the drive cycle pattern. Refer to OBD-II Drive Cycle OBD-II DRIVE CYCLE.
(2) Check the DTC.
Is the DTC set?
The trouble can be an intermittent malfunction (Refer to General Information - How to Use Troubleshooting/Inspection Service Points, How to Cope with Intermittent Malfunctions HOW TO COPE WITH INTERMITTENT MALFUNCTIONS).