US 12,140,115 B2
Engine start abnormality diagnosis apparatus
Kei Iizuka, Tokyo (JP); Yasuhiro Oota, Tokyo (JP); Kyouhei Degura, Tokyo (JP); and Noriyuki Matsuda, Tokyo (JP)
Assigned to SUBARU CORPORATION, Tokyo (JP)
Filed by SUBARU CORPORATION, Tokyo (JP)
Filed on Aug. 17, 2023, as Appl. No. 18/451,305.
Claims priority of application No. 2022-146274 (JP), filed on Sep. 14, 2022.
Prior Publication US 2024/0084773 A1, Mar. 14, 2024
Int. Cl. F02N 11/00 (2006.01); F02N 11/10 (2006.01); F02B 75/18 (2006.01)
CPC F02N 11/108 (2013.01) [F02B 2075/1808 (2013.01); F02B 2075/1816 (2013.01); F02N 2200/022 (2013.01)] 4 Claims
OG exemplary drawing
 
1. An engine start abnormality diagnosis apparatus configured to determine a cause of a long cranking abnormality in which, when an engine comprising cylinders is started, start of the engine is not completed even if a cranking period is equal to or greater than a predetermined time, the engine start abnormality diagnosis apparatus comprising:
a rotation speed detector configured to detect a rotation speed of a crankshaft of the engine when at least one of the cylinders is in a latter stage of a compression stroke; and
an abnormality diagnosis processor configured to determine that the cause of the long cranking abnormality is an electric system abnormality when the rotation speed detected by the rotation speed detector is less than a predetermined threshold, and determine that the cause of the long cranking abnormality is a combustion abnormality when the rotation speed is equal to or greater than the threshold.