Diagnostic method for motor vehicles for checking electronically controlled systems

• US 5,757,645 A
• Filed: 11/22/1995
• Issued: 05/26/1998
• Est. Priority Date: 06/18/1993
• Status: Expired due to Fees

• Current Assignee: Bayerische Motoren Werke AG
• Original Assignee: Bayerische Motoren Werke AG
• Inventors: Hohenner, Hans, Schneider, Josef
• Primary Examiner(s): Teska, Kevin J.
• Assistant Examiner(s): NGUYEN, TAN QUANG
• Application Number:
  US08/562,350
• Time in Patent Office: 916 Days
• Field of Search: 364/424.03, 364/424.06, 364/424.05, 364/551.01, 364/571.01, 364/571.02, 364/571.04, 364/579, 364/580, 364/424.034, 364/424.035 , 364/424.036, 364/424.038, 364/424.039, 371/3, 371/20.4
• US Class Current: 701/29
• CPC Class Codes: F02B 77/083 relating to maintenance, e.g. diagnostic device relating to lubrication F01M11/10
• CPC Class Codes: G01R 31/007 using microprocessors or computers
• CPC Class Codes: G06F 11/2273 Test methods
• CPC Class Codes: G07C 5/0808 Diagnosing performance data testing of vehicles G01M17/00; testing of electrical installation on vehicles G01R31/005

Abstract

A diagnostic method for motor vehicles with a diagnostic device for checking electronically controlled systems, in which a fault memory provided in an electronic control device is interrogated and in which test steps to be performed in accordance with the information in the fault memory are prescribed. The test steps performed in response to the prescribed test steps are recorded in the electronic control device.

Claims

1. Diagnostic method for motor vehicles, said method using a diagnostic device to check electronically controlled systems and to store prescribed test steps for diagnosing faults, said motor vehicle having an on-board electronic control device with a fault memory and with an actual test step memory, the method comprising the steps of:

using the diagnostic device to interrogate the fault memory provided in the electronic control device to determine a recorded fault; and

at least partially recording test steps actually performed in accordance with the prescribed test steps which correspond to the recorded fault, in the actual test step memory.

2. Diagnostic method according to claim 1, wherein the step of recording the test steps actually performed includes recording the test steps actually performed in chronological sequence.

3. Diagnostic method according to claim 1, further comprising comparing the recorded test steps actually performed with the prescribed test steps.

4. Diagnostic method according to claim 3, further comprising displaying a message indicating that at least one of the prescribed test steps is not included in the recorded test steps actually performed.

5. Diagnostic method according to claim 4, further comprising displaying another message indicating that the recorded test steps actually performed differ in sequence from a sequence of the prescribed test steps.

6. Diagnostic method according to claim 3, further comprising storing a message when at least one of the prescribed test steps is not included in the recorded test steps actually performed.

7. Diagnostic method according to claim 6, further comprising displaying another message when the recorded test steps actually performed differ in sequence from a sequence of the prescribed test steps.

8. Diagnostic method according to claim 6, further comprising storing the message in a nonvolatile form in the electronic control device of the electronically controlled system to be checked.

9. Diagnostic method according to claim 1, wherein said at least partially recording test steps comprises storing the test steps actually performed in a nonvolatile form in the electronic control device of the electronically controlled system to be checked.

10. Diagnostic method according to claim 1, wherein said electronic control device further comprises a prescribed test step memory, the method further comprising at least partially storing said prescribed test steps for diagnosing faults in said prescribed test step memory.

11. Diagnostic method for motor vehicles, said method using a diagnostic device to check electronically controlled systems and to store prescribed test steps for diagnosing faults, said motor vehicle having a replaceable on-board electronic control device with a fault memory and with an actual test step memory, the method comprising the steps of:

using the diagnostic device to interrogate the fault memory provided in the electronic control device to determine a recorded fault; and

at least partially recording test steps actually performed in accordance with the prescribed test steps which correspond to the recorded fault, in the actual test step memory.

12. Diagnostic method according to claim 11, wherein said electronic control device further comprises a prescribed test step memory, the method further comprising at least partially storing said prescribed test steps for diagnosing faults in said prescribed test step memory.