Connect tester (in ohmmeter mode) to the plugs of connector 1 of switch 2 and measure the resistance, which, when the switch is opened, (when the throttle lever 3 comes into contact with it) must be R=∞, when the circuit breaker closes (when moving away from the throttle lever) it must be less than 15 ohms.
If the resistance values are not correct, replace the servo.