On-board diagnostic method for monitoring diesel oxidation catalyst function via brick temperature rise

A method for monitoring diesel oxidation catalyst function via a brick temperature rise, comprising:

• pre-storing hydrocarbons on a catalyst coating in a catalyst coated body;
• positioning a diesel oxidation catalyst (DOC) exhaust treatment device in an exhaust conduit of a diesel engine, the DOC exhaust treatment device including the catalyst coated body;
• forwarding a first exhaust gas temperature output defining an inlet gas temperature received in the DOC exhaust treatment device to a control module;
• recording in the control module a time for the inlet gas temperature to reach a target temperature;
• and
• comparing in the control module the time for the inlet gas temperature to reach the target temperature to a time required for a brick temperature of the catalyst coated body to reach the same target temperature.

A method for monitoring diesel oxidation catalyst function via a brick temperature rise, comprising:

• providing a first exhaust gas temperature sensor outputting a first exhaust gas temperature for an exhaust conduit collecting exhaust from a diesel engine;
• positioning a diesel oxidation catalyst (DOC) exhaust treatment device in the exhaust conduit downstream of the first exhaust gas temperature sensor, the DOC exhaust treatment device having a catalyst coated body;
• incorporating a second exhaust gas temperature sensor in the catalyst coated body of the DOC exhaust treatment device;
• forwarding an output signal from each of the first exhaust gas temperature sensor defining an inlet gas temperature received in the DOC exhaust treatment device, and an output signal from the second exhaust gas temperature sensor defining a brick temperature of the catalyst coated body to a control module;
• recording in the control module a time for the inlet gas temperature to reach a target temperature;
• and
• comparing in the control module the time for the inlet gas temperature to reach the target temperature to a time required for the brick temperature of the catalyst coated body to reach the same target temperature.