US 12,012,882 B1
Vehicle bypass catalyst diagnostic system
Steven C Wante, Chelsea, MI (US); and Roger C Sager, Munith, MI (US)
Assigned to FCA US LLC, Auburn Hills, MI (US)
Filed by FCA US LLC, Auburn Hills, MI (US)
Filed on Jun. 27, 2023, as Appl. No. 18/342,309.
Int. Cl. F01N 11/00 (2006.01); F01N 3/28 (2006.01); F01N 13/00 (2010.01); F02B 37/18 (2006.01); G01M 15/10 (2006.01); G07C 5/08 (2006.01)
CPC F01N 11/007 (2013.01) [F01N 3/2892 (2013.01); F01N 13/008 (2013.01); F01N 13/0093 (2014.06); F02B 37/183 (2013.01); G01M 15/104 (2013.01); G07C 5/0808 (2013.01); G07C 5/0825 (2013.01); F01N 2410/06 (2013.01); F01N 2550/02 (2013.01); F01N 2550/10 (2013.01); F01N 2560/025 (2013.01); F01N 2900/0416 (2013.01); F01N 2900/0418 (2013.01); F01N 2900/1624 (2013.01)] 20 Claims
OG exemplary drawing
 
1. An internal combustion engine system comprising:
an internal combustion engine;
a main exhaust aftertreatment system with a main catalytic converter configured to receive exhaust gas from the internal combustion engine;
a light-off catalyst bypass system with a bypass passage and a bypass catalytic converter configured to selectively receive exhaust gas from the internal combustion engine; and
an emissions control system including a controller in signal communication with a first oxygen sensor disposed upstream of the bypass catalytic converter, and a second oxygen sensor disposed downstream of the bypass catalytic converter, wherein the emissions control system is configured to perform a diagnostic of the bypass catalytic converter, comprising:
monitoring, by the controller, signals from the first and second oxygen sensors for a predetermined time period during an engine cold start condition;
determining, by the controller, a ratio of oxygen content at the second oxygen sensor to oxygen content at the first oxygen sensor based on the signals from the first and second oxygen sensors; and
comparing, by the controller, the determined ratio to a predetermined threshold ratio to determine if the bypass catalytic converter has failed.