Patent ID: 6877354

Claim:
A method for balancing ozone sensors for the onboard diagnosis of a catalytic element, which is arranged in a vehicle and is exposed to an ambient airstream, for breaking down ozone, in which a first ozone sensor is exposed to the ambient airstream upstream of the catalytic element and a second ozone sensor ( 4 ) is exposed to the ambient airstream downstream of the catalytic element, the method comprising the steps of: checking predetermined enable conditions necessary for the sensor balancing to proceed, if the enable conditions are fulfilled, recording output signal values from the first and second ozone sensors, comparing the output signal values with one another, and obtaining a deviation value which is characteristic of the deviation between the two values, using the deviation value to determine whether sensor balancing is required and possible, if sensor balancing is required and possible, comparing the output signal values from the first and second ozone sensors with a threshold value and depending on the comparison result, performing either an additive or a multiplicative correction of the output signal values.