Patent ID: 9726086
Date: 2017-08-08
CPC Classifications: F02D

Claim:
1. A device for diagnosing failure of an exhaust brake, comprising: a diagnosis circuit for determining, on the basis of absolute values of variations, before and after actuation of said exhaust brake, of fuel-injection and intake-air amounts, respectively, that the exhaust brake normally operates when the absolute value of the variation, before and after the actuation of said exhaust brake, of the fuel-injection amount is not less than a fuel-injection variation threshold and the absolute value of the variation, before and after the actuation of said exhaust brake, of the intake-air amount is not less than an intake-air variation threshold and determining that said exhaust brake has a failure when the absolute value of the variation, before and after the actuation of said exhaust brake, of said fuel-injection amount is less than the fuel-injection variation threshold and the absolute value of the variation, before and after the actuation of said exhaust brake, of said intake-air amount is less than the intake-air variation threshold, wherein upon determining that said exhaust brake has the failure, an exhaust flow rate is throttled to rise a temperature of an aftertreatment device for exhaust emission control incorporated in an exhaust pipe of an engine to a required temperature during idling.