Abstract: In a vehicle diagnostic system and a vehicle diagnostic method, malfunction codes recorded in each ECU in a vehicle include idle stop malfunction codes that disallow idle stop, and a non-idle stop malfunction code that does not disallow idle stop. The idle stop malfunction codes include: a first idle stop malfunction code that operates a warning light provided corresponding to a specific ECU; and a second idle stop malfunction code that does not operate the relevant warning light. An external diagnostic device extracts, from the plurality of ECUs, only the second idle stop malfunction codes, among the first idle stop malfunction codes and the second idle stop malfunction codes, when performing malfunction diagnosis for non-execution of idle stop.

Abstract: Provided are a vehicle diagnostic system, a vehicle diagnostic method, and an external diagnostic device that are capable of readily or promptly confirming or diagnosing whether or not a malfunction related to non-execution of idle stop in a vehicle having an idle stop control system has occurred. The external diagnostic device has recorded therein a plurality of idle stop conditions for executing idle stop of an engine in a vehicle. Idle stop conditions that are not fulfilled when idle stop has not executed are displayed in a prescribed display unit, when stopping the vehicle when the external diagnostic device has been connected to the vehicle and the vehicle has been driven.

Abstract: Provided are a vehicle diagnostic system, a vehicle diagnostic method, and an external diagnostic device that are capable of readily or promptly confirming or diagnosing whether or not a malfunction related to non-execution of idle stop in a vehicle having an idle stop control system has occurred. The external diagnostic device has recorded therein a plurality of idle stop conditions for executing idle stop of an engine in a vehicle. Idle stop conditions that are not fulfilled when idle stop has not executed are displayed in a prescribed display unit, when stopping the vehicle when the external diagnostic device has been connected to the vehicle and the vehicle has been driven.

Abstract: In a vehicle diagnostic system and a vehicle diagnostic method, malfunction codes recorded in each ECU in a vehicle include idle stop malfunction codes that disallow idle stop, and a non-idle stop malfunction code that does not disallow idle stop. The idle stop malfunction codes include: a first idle stop malfunction code that operates a warning light provided corresponding to a specific ECU; and a second idle stop malfunction code that does not operate the relevant warning light. An external diagnostic device extracts, from the plurality of ECUs, only the second idle stop malfunction codes, among the first idle stop malfunction codes and the second idle stop malfunction codes, when performing malfunction diagnosis for non-execution of idle stop.