Method for checking the coupling of two reference points which are movable with respect to one another, in particular for checking the mechanical coupling between a first reference point on the vehicle body of a motor vehicle and a second reference point on the chassis, the distance between the reference points being measured between a lower and an upper distance limit by means of a sensor, the measurement range of which is subdivided into a plurality of successive measurement sub-ranges of the same size, each sub-range of which generates the same signal profile, characterized in that a) the signal from the sensor is supplied to a first comparator which compares the signal with an upper signal threshold value of a measurement sub-range and outputs a first binary output signal assigned to the state "exceeding of the upper signal threshold value" if the signal threshold value is exceeded, b) the signal from the sensor is supplied to a second comparator which compares the signal with a lower signal threshold value of a measurement sub-range and outputs a second binary output signal assigned to the state "undershooting of the lower signal threshold value" if the signal threshold value is undershot, c) the first output signal from the first comparator is supplied both to a first memory and to an inverter which converts the first output signal into its inverse value and outputs it as an inverted first output signal, d) the second output signal from the second comparator is supplied both to a second memory and to an inverter which converts the second output signal into its inverse value and outputs it as an inverted second output signal, e) the inverted first output signal and the inverted second output signal are supplied to a first AND gate which, if both inverted output signals are present, outputs a third binary output signal which is supplied both to the first and to the second memory as a reset signal (reset), f) the first memory outputs a fourth binary output signal assigned to the state "exceeding of the upper signal threshold value" to a second AND gate if the first output signal is applied and is reset if the third output signal is applied, g) the second memory outputs a fifth binary output signal assigned to the state "undershooting of the lower signal threshold value" to the second AND gate if the second output signal is applied and is reset if the third output signal is applied, wherein h) the second AND gate outputs a sixth binary output signal at the output of the second AND gate if the fourth and fifth output signals are applied, which sixth binary output signal is provided as an indication of non-existent coupling of a vehicle controller. a) the signal from the sensor is supplied to a first comparator which compares the signal with an upper signal threshold value of a measurement sub-range and outputs a first binary output signal assigned to the state "exceeding of the upper signal threshold value" if the signal threshold value is exceeded, b) the signal from the sensor is supplied to a second comparator which compares the signal with a lower signal threshold value of a measurement sub-range and outputs a second binary output signal assigned to the state "undershooting of the lower signal threshold value" if the signal threshold value is undershot, c) the first output signal from the first comparator is supplied both to a first memory and to an inverter which converts the first output signal into its inverse value and outputs it as an inverted first output signal, d) the second output signal from the second comparator is supplied both to a second memory and to an inverter which converts the second output signal into its inverse value and outputs it as an inverted second output signal, e) the inverted first output signal and the inverted second output signal are supplied to a first AND gate which, if both inverted output signals are present, outputs a third binary output signal which is supplied both to the first and to the second memory as a reset signal (reset), f) the first memory outputs a fourth binary output signal assigned to the state "exceeding of the upper signal threshold value" to a second AND gate if the first output signal is applied and is reset if the third output signal is applied, g) the second memory outputs a fifth binary output signal assigned to the state "undershooting of the lower signal threshold value" to the second AND gate if the second output signal is applied and is reset if the third output signal is applied, wherein h) the second AND gate outputs a sixth binary output signal at the output of the second AND gate if the fourth and fifth output signals are applied, which sixth binary output signal is provided as an indication of non-existent coupling of a vehicle controller.