摘要 |
The invention provides for a method for operating an SCR catalytic converter for the aftertreatment of exhaust gases of an internal combustion engine, wherein a reducing agent tank (1) with reducing agent and a reducing agent metering device (8) are provided. The reducing agent tank (1) has at least one tank heater (3) having PTC characteristics. A variable characterizing the heater current is acquired for detecting cavities (10) in the reducing agent tank (1) when the reducing agent is frozen. The presence of cavities is suggested from a deviation of the acquired value or values for the variable characterizing the heater current from a predeterminable reference value, which represents a reducing agent tank without cavities.
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