Introduction

INTRODUCTION
The Engine Control Module (ECM) (ECCS control module) has an on-board diagnostic system, which detects engine system malfunctions related to sensors or actuators. The Malfunction Indicator Lamp (MIL) on the instrument panel lights up when the same malfunction is detected in two consecutive trips (Two Trip Detection Logic).




Two Trip Detection Logic
When a malfunction is detected for the first time, the malfunction (DTC and freeze frame data) is stored in the ECM memory. (1st trip) The malfunction indicator lamp will not light up at this stage.
If the same malfunction is detected during the next drive, this second detection causes the malfunction indicator lamp to light up. (2nd trip) Specific on-board diagnostic items will light up or blink the MIL even in the 1st trip as below.
The "trip" in the "Two Trip Detection Logic" means performing of the "DTC Confirmation Procedure".