Method of detecting and documenting exhaust-gas relevant malfunctions of a vehicle having an internal combustion engine utilizing onboard means

• US 5,783,990 A
• Filed: 02/26/1997
• Issued: 07/21/1998
• Est. Priority Date: 02/28/1996
• Status: Expired due to Fees

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Dambach, Dieter-Andreas
• Primary Examiner(s): Hofsass, Jeffery A.
• Assistant Examiner(s): LA, ANH V
• Application Number:
  US08/806,412
• Time in Patent Office: 510 Days
• Field of Search: 340/438, 340/450.2, 340/439, 340/450, 340/459, 340/460, 340/461, 340/451, 123/690, 123/676, 701/103, 701/101, 701/29, 701/109, 701/108
• US Class Current: 340/438
• CPC Class Codes: B60R 16/0315 using multiplexing techniques multiplexing for transmission of signals G08C15/00; multiplexing for electrical communication in general H04J
• CPC Class Codes: F01N 11/00 Monitoring or diagnostic devices for exhaust-gas treatment apparatus , e.g. for catalytic activity safety, indicating or supervising devices for internal combustion engines F02B77/08; testing of machines G01M13/00
• CPC Class Codes: F01N 2550/02 Catalytic activity of catalytic converters
• CPC Class Codes: F01N 9/00 Electrical control of exhaust gas treating apparatus monitoring or diagnostic devices for exhaust-gas treatment apparatus F01N11/00; conjoint electrical control of two or more combustion engine functions F02D43/00
• CPC Class Codes: F01N 9/007 Storing data relevant to operation of exhaust systems for later retrieval and analysis, e.g. to research exhaust system malfunctions
• CPC Class Codes: F02D 41/22 Safety or indicating devices for abnormal conditions in air/fuel ratio feedback systems F02D41/1495, in electric control linkage F02D11/107, in purge control systems F02M25/0809
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

The invention is directed to a method of detecting and documenting exhaust-gas relevant malfunctions of a vehicle equipped with an internal combustion engine utilizing onboard equipment. Malfunctions are detected by a sensor device and evaluated in a circuit unit. The malfunction is displayed by a warning lamp (fault announcement) and is stored in a fault memory. A pressure measurement in the fuel loop is made and the output as well as the storage of the fault announcement is made in dependence upon the measured pressure. This is done to differentiate fault announcements based on a fuel tank run to empty.

Claims

1. A method of detecting and documenting exhaust-gas relevant malfunctions of a vehicle having an internal combustion engine and onboard means which includes a control circuit, the method being carried out with the aid of said onboard means and comprising the steps of:

detecting said malfunctions utilizing detecting means and evaluating said malfunctions in said control circuit;

switching on a warning lamp to display said malfunctions as a fault announcement;

measuring the pressure in the fuel loop with a pressure sensor and supplying a signal representing said pressure to said control circuit; and

storing said fault announcement in a fault memory in dependence upon the measured pressure.

2. The method of claim 1, wherein a malfunction is always displayed by said warning lamp and stored in said fault memory when said pressure drops below a pregiven value.

3. The method of claim 2, wherein said vehicle further has a fuel supply system for said internal combustion engine, said method comprising the further steps of detecting combustion misfires and/or disturbances in the fuel supply system as an additional malfunction;

and, displaying and storing said additional malfunctions.

4. The method of claim 3, further comprising the steps of:

storing the pressure drops within the fuel loop and the combustion misfires detected simultaneously or within pregiven time intervals as an additional fault code in said fault memory.

5. The method of claim 1, wherein the pressure in the fuel loop is measured with a pressure sensor mounted in the fuel feed of said fuel loop.

6. The method of claim 5, wherein said pressure sensor is a sensor having an analog output quantity or a contact switch.

7. The method of claim 1, wherein said engine includes an engine control arrangement and said control circuit is part of said control arrangement.

8. The method of claim 7, wherein said fault memory is part of said control arrangement and is adapted to be read out externally for diagnostic purposes.