Diagnostic method for a sensor

• US 7,095,238 B2
• Filed: 09/12/2003
• Issued: 08/22/2006
• Est. Priority Date: 02/07/2003
• Status: Expired due to Fees

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Gintner, Klemens, Walter, Klaus, Steinruecken, Heinrich, Rettig, Rasmus
• Primary Examiner(s): Benson, Walter
• Application Number:
  US10/532,695
• Publication Number:
  US 20060152226A1
• Time in Patent Office: 1,075 Days
• Field of Search: 324/503, 324/509
• US Class Current: 324/509
• CPC Class Codes: F02D 41/009 using means for generating position or synchronisation signals
• CPC Class Codes: F02D 41/222 relating to the failure of sensors or parameter detection devices
• CPC Class Codes: G01D 3/08 with provision for safeguarding the apparatus, e.g. against abnormal operation, against breakdown

Abstract

In a method for diagnosis of a sensor in a motor vehicle having an internal combustion engine, during operation of the motor vehicle, an output signal of the sensor is monitored for whether a maximum value of the output signal undershoots a first threshold value and/or a minimum value of the output signal overshoots a second threshold value. In that case a signal is forwarded to a controller that signals to the controller that the sensor, upon restarting of the motor vehicle, might be furnishing incorrect data.

Claims

1. A method for diagnosis of a sensor in a motor vehicle having an internal combustion engine, comprising the following steps:

during operation of the motor vehicle, monitoring an output signal of the sensor for whether a maximum value of the output signal undershoots a first threshold value and/or a minimum value of the output signal overshoots a second threshold value;

forwarding a signal to a controller that signals to the controller that the sensor, upon restarting of the motor vehicle, might be furnishing incorrect data if the maximum value of the output signal undershoots the first threshold value and/or the minimum value of the output signal overshoots the second threshold value; and

wherein the undershooting or exceeding of the threshold value is used for diagnosis of the sensor.

2. The method as recited in claim 1, wherein the first threshold value is equal to the second threshold value.

3. The method as recited in claim 1, wherein in the event of undershooting or overshooting of the threshold values, the output signals of the sensor upon restarting of the motor vehicle are initially not used for the control and/or regulation of the motor vehicle.

4. The method as recited in claim 3, wherein the sensor is not used again for the control and/or regulation of the motor vehicle until calibration of the sensor has been done.

5. The method as recited in claim 4, wherein the calibration is done by learning minimum and maximum output values of the sensor.

6. The method as recited in claim 3, wherein starting of the engine in emergency operation is done without using the phase sensor.

7. The method as recited in claim 1, wherein the signal in the controller is stored in a nonvolatile memory so that the signal will be directly available upon restarting of the engine.

8. The method as recited in claim 1, wherein the sensor is a phase sensor on a camshaft of the engine.

9. The method as recited in claim 1, wherein the threshold values are stored in a permanent memory of the sensor.

10. The method as recited in claim 9, that by means of a calibration of the sensor, the threshold values are adapted.

11. The method as recited in claim 1, wherein the forwarding of the signal is done in encoded form.

12. A sensor having means for performing the method of claim 1.