In this paper, we investigate the trend of injector waveform change due to failure of air flow sensor and intake air temperature sensor of CRDI engine. Changes in the injector opening time can be detected by the failure of the associated sensor, and the extension of the reaction time is closely related to fuel consumption. Thus, the proper maintenance time of the vehicle will affect the fuel economy and reduce the exhaust gas.

• 이근종(Member, s Ph D Graduate in the School of Automotive Engineering of Gangneung-Wonju National University) | Geun-jong Lee Corresponding author
• 김철수(Member, Gangneung-Wonju National University School of Mechanical & Automotive Engineering) | Chul-Soo Kim