Scan tool with dropped communications detection and recovery and improved protocol selection

Abstract

An improved scan tool, e.g., for OBD II, for use with vehicle computer networks. The improved scan tool determines the proper protocol to use to communicate with a vehicle computer network. The proper protocol is determined by requesting information from the vehicle computer network using a plurality of protocols and selecting the protocol that returns the most pieces of information. In addition, the improved scan tool determines a communications drop-out with one or more modules and automatically recovers from a the communications drop-out.

Description

BACKGROUND OF THE INVENTION [0001]“Off-board devices,” such as scan tools, are known in the art and are testing devices that interface with vehicle diagnostic systems to access, display, and / or print vehicle diagnostic information. OBD II (On-Board Diagnostics version II) Scan Tools are one commonly known type of scan tool and are governed by a number of standards, e.g., SAE J1978 Rev. 1988-02 and SAE J1979 Rev. 1997-09. [0002] There are a number of problems with the existing scan tools and scan tool specifications. For example, in certain vehicles, e.g., various model years of HYUNDAI, VW, DODGE, and VOLVO vehicles, the known scan tools have communications drop-outs. One minute the user will be using a scan tool and be examining e.g., 28 different parameters, and the next instant there is no response for all but e.g., three, of the parameters. What the user does not know is that one or more controllers, e.g., the engine controller, which is typically the main ODB II controller, has...

AI Technical Summary

Benefits of technology

[0010] It is therefore an advantage of the present invention to provide an improved scan tool that determines the protocol that provides the most relevant vehicle information (e.g., the protocol that provides the most emissions information).

[0011] It is also an advantage of the present invention to provide an improved scan tool that determines when a module has had a communications drop-out.

[0012] It is another advantage of the present invention to provide an improved scan tool that automatically recovers from a communications drop-out.

[0013] It is a further advantage of this invention to provide an improved scan tool that automatically recovers from a communications drop-out without requiring that the protocol be re-determined.

[0014] It is yet another advantage of the present invention to provide an improved scan tool that determines when a module has had a communications drop-out and that automatically recovers from a communications drop-out.

[0015] These and other advantages of the present invention will become more apparent from a

Problems solved by technology

There are a number of problems with the existing scan tools and scan tool specifications.

Therefore a scan tool following the recommendation is unable to determine the correct protocol and therefore unable to use all the covered OBD II functions and read all the available information from the vehicle.

This causes the scan tool to incorrectly choose the protocol being used by the transaxle as the OBD II protocol for this type of vehicle rather than the protocol being used by the engine controller.

This type of problem can happen in other protocol combinations also.

This type of system is subject to one or more of the modules to losing their active communication with off-board devices, like scan tools.

If the scan tool does not realize that one or more of the modules has dropped the link, it will not be showing complete / correct data.

Once again during on-vehicle testing the inventors discovered that multiple module vehicles present certain problems.

For example certain VW models that use an engine control module and a transaxle control module presented a problem.

These problems can result in OBD II information being misreported.

Images