Abstract: Methods and systems are provided for cleaning a urea-clogged diesel exhaust fluid (DEF) injector included in a selective catalytic reduction (SCR) engine exhaust after-treatment system. In one example, a method may include, responsive to a diagnostic code indicating a clogged DEF injector, operating an engine in a DEF injector cleaning mode comprising operating the engine at a high idle speed, activating a DEF pump to deliver a desired amount of DEF at a desired flowrate, and measuring a duty cycle of DEF pump activation during DEF delivery. Responsive to the duty cycle being greater than a threshold duty cycle for a duration, DEF flow restoration is indicated.

Abstract: Methods and systems are provided for cleaning a urea-clogged diesel exhaust fluid (DEF) injector included in a selective catalytic reduction (SCR) engine exhaust after-treatment system. In one example, a method may include, responsive to a diagnostic code indicating a clogged DEF injector, operating an engine in a DEF injector cleaning mode comprising operating the engine at a high idle speed, activating a DEF pump to deliver a desired amount of DEF at a desired flowrate, and measuring a duty cycle of DEF pump activation during DEF delivery. Responsive to the duty cycle being greater than a threshold duty cycle for a duration, DEF flow restoration is indicated.

Abstract: An embodiment of the present invention includes an apparatus for remotely testing a plurality of communication channel inputs to an automobile computer. The apparatus may include a microprocessor electrically connected to a persistent memory. The memory may have stored therein communication channel test messages corresponding to each of two or more communication channel inputs to an automobile computer. At least one of the communication channels is a wireless communication channel. The microprocessor may be configured to output a test message over a selected communication channel to the automobile computer.

Abstract: An embodiment of the present invention includes an apparatus for remotely testing a plurality of communication channel inputs to an automobile computer. The apparatus may include a microprocessor electrically connected to a persistent memory. The memory may have stored therein communication channel test messages corresponding to each of two or more communication channel inputs to an automobile computer. At least one of the communication channels is a wireless communication channel. The microprocessor may be configured to output a test message over a selected communication channel to the automobile computer.