US 12,216,180 B2 · Method and apparatus for diagnosing an exhaust gas sensor

Abstract

A method and a device for performing diagnostics on an exhaust gas sensor includes a series circuit of a Nernst cell and a first other cell. The exhaust gas sensor has a first, a second, and a third connection where a voltage drop can be measured between the first connection and the second connection by the Nernst cell and a voltage drop between the second connection and the third connection can be measured by the first other cell. The diagnostic method has steps for feeding a direct or alternating current into the first, second, and third connections; for directly or indirectly sensing an electrical voltage potential at at least one of the first, second, and third connections; and for evaluating the voltage potential sensed to diagnose a short circuit or an open circuit in the Nernst cell and/or in the first other cell.

Claims20

Dependent claims

A diagnostic method for an exhaust gas sensor, the exhaust gas sensor having a series circuit of a Nernst cell and a further cell, and the exhaust gas sensor has a first connection, a second connection, and a third connection, and wherein a voltage drop across the Nernst cell is measurable between the first and second connections and a voltage drop across the further cell is measurable between the second and third connections, the diagnostic method comprising:

selectively feeding, by a multiplexer, a direct current or an alternating current from a single current source directly into the first, second, and third connections;
directly or indirectly capturing an electrical voltage potential at at least one of the first, second, or third connections;
and
evaluating the captured electric voltage potential for diagnosing a short circuit or a line break in at least one of the Nernst cell or the further cell.

1 more element

An apparatus for diagnosing an exhaust gas sensor having a series circuit with a Nernst cell and a further cell, the exhaust gas sensor having a first connection, a second connection, and a third connection, and a voltage drop across the Nernst cell is measurable between the first and second connections and a voltage drop across the further cell is measurable between the second and third connections, the apparatus comprising:

a multiplexer configured for selectively feeding a direct current or an alternating current from a single current source directly into the first, second, and third connections;
a device for directly or indirectly capturing an electrical voltage potential at at least one of the first, second, or third connections;
and
an evaluation device for evaluating the electrical voltage potential captured at one or more of the first, second, or third connections in order to diagnose a short circuit or a line break in one or both of the Nernst cell or the further cell.

1 more element

Dependencies are inferred from the claim text.

Method and apparatus for diagnosing an exhaust gas sensor

Life of this patent

Method and apparatus for diagnosing an exhaust gas sensor

Life of this patent

Abstract

Claims20