Exhaust throttle valve diagnosing device and method
When switching an exhaust throttle valve from full opening to a closed position to warm up an engine, an intake throttle valve is fixed to full opening, an EGR valve is fixed to full closing, and a variable turbo-vane is fixed to a predetermined opening degree to accelerate a gas flow rate from an i...
Saved in:
| Main Authors | , |
|---|---|
| Format | Patent |
| Language | English |
| Published |
25.12.2012
|
| Online Access | Get full text |
Cover
Loading…
| Summary: | When switching an exhaust throttle valve from full opening to a closed position to warm up an engine, an intake throttle valve is fixed to full opening, an EGR valve is fixed to full closing, and a variable turbo-vane is fixed to a predetermined opening degree to accelerate a gas flow rate from an intake passage to an exhaust passage, a fully opened flow rate is detected and stored by gas flow rate detector, with the exhaust throttle valve being full opening. Then, an instruction is issued to the exhaust throttle valve to switch from the full opening to a closed position, after which a rotation number of the engine is detected, a threshold value is determined based thereon, a closed position flow rate is detected, a flow rate difference relative to the stored fully opened flow rate is determined, and failure of the exhaust throttle valve is judged based on whether the flow rate difference is less than the determined threshold value. |
|---|