| 摘要 |
The invention relates to a method for detecting a voltage offset at least in a portion of a voltage lambda characteristic curve (10) of a two-point lambda sensor arranged in an exhaust gas channel of an internal combustion engine with respect to a reference voltage lambda characteristic curve (12) of the two-point lambda sensor. The two-point lambda sensor is part of a control system for adjusting an air/fuel mixture supplied to the internal combustion engine, a deviation of the voltage lambda characteristic curve (10) from the reference voltage lambda characteristic curve (12) being corrected when lambda = 1. On the basis of a value pair (24) to be checked on the reference voltage lambda characteristic curve (12) with a lambda (28) to be checked and a voltage (26) to be checked, the composition of the air/fuel mixture supplied to the internal combustion engine is changed until lambda = 1, and the actual value of lambda (30) is inferred from the change of the air/fuel mixture composition until lambda = 1. In a first method step, a delay time of the control system is determined, and in a second method step, the composition of the air/fuel mixture is changed on the basis of the value pair (24) to be checked until lambda = 1, wherein the change of the composition is corrected using the delay time of the control system, the actual value of lambda (30) in the value pair (24) is determined from the corrected change of the air/fuel mixture composition, and a voltage offset of the voltage lambda characteristic curve (10) is detected from a deviation of the actual value of lambda (30) from the lambda (28) value to be checked. The first method step and the second method step are carried out if a property of a fuel injection quantity supplied to the internal combustion engine falls below or exceeds a threshold. |
