| CPC F01N 3/208 (2013.01) [F01N 3/103 (2013.01); F01N 3/2033 (2013.01); F01N 3/2066 (2013.01); F01N 2240/16 (2013.01); F01N 2900/1602 (2013.01)] | 4 Claims |

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1. A method for operating an exhaust gas post-treatment device for an internal combustion engine of a motor vehicle, wherein exhaust gas from the internal combustion engine flows through the exhaust gas post-treatment device, and wherein the exhaust gas post-treatment device comprises: an oxidation catalyst with a first catalytic coating, a first heating element disposed upstream of the oxidation catalyst or with the first catalytic coating and configured to heat the exhaust gas and/or the oxidation catalyst at a first heating point, a dosing element configured to introduce a reducing agent is into the exhaust gas at an introduction point downstream of the oxidation catalyst and the first heating point, and an SCR system having a first SCR catalyst disposed downstream of the introduction point, the method comprising:
determining: that a temperature downstream of the first heating point and a temperature of the SCR system are below respective target temperatures, that component protection temperatures are not exceeded, and that a minimum temperature of the internal combustion engine for carrying out a post-injection has been reached or exceeded;
calculating a temperature rise by which the temperature of the SCR system is to be increased such that the temperature of the SCR system reaches its respective target temperature;
determining whether the temperature rise can be achieved within a pre-determined duration by the first heating element without carrying out the post-injection;
in response to determining that the temperature rise can be achieved within the pre-determined duration by the first heating element without carrying out the post-injection, then the exhaust gas, and thus the SCR system, via the first heating element, without carrying out the post-injection; and
in response to determining that the temperature rise cannot be achieved within the pre-determined duration by the first heating element without carrying out the post-injection, heating the exhaust gas, and thus the SCR system, via the first heating element and by carrying out the post-injection.
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