SAE J2054 pdf download

SAE J2054 pdf download.E/E Diagnostic Data Communications.
This SAE Information Report describes the diagnostic data communications required for wnpfemeritation of a set of diagnostic test modes for all electronic systems on the vehicle’s serial data link. These test modes can be used by off-board test equipment for both service and assently plant testing.
The goal of this document is to provide standard methods to perform common functions for all electronic systems. This standard set of procedures will aid development, production, and field service of those systems. Use of the standard data communications in this specification will potentially result in the bLowing benefits:
Common methods and procedures for developers to use, without the need to invent methods to perform these functions
Common programning techniques for system programmers, with increased sharing of software procedures
Common hardware, software and test procedures for assembly plant testing
Common hardware, software and service procedures for service diagnostics across different vehicle manufacturers and systems
This specification includes:
Diagnostic Message Formats
Device ID’s
Functional descriptions of all diagnostic test modes
Message and response formats for all diagnostic test modes
1.1 Purpose—The diagnostic test modes (DTM) provide off-board test equipment with communication aocess to the on•board vehicle electronic systems. The off-board equipment shall be able to interrogate the electronic systems on the vehicle, and exercise control over these systems for the purposes of verifying system operation and diagnosing malfunction conditions,
Diagnostic tesl modes are predefined and standardized for all systems on the vehice. Each device on the vehicle will implement only those DTMs which are appropriate for that device. Not all modes will be implemented on each device. If use of these modes Is not appropriate for a given application, or during some operating modes, then that device is responsible to verify safe and proper operation and not respond to the request.
2. References
2.1 ApplIcable Publications—The following publications form a part of this 5peciflcation to the extent specified herein. The latest issue of SAE publications shall apply.
2.1.1 SAE PuBLICAriceis—Available from SAE, 400 Commonwealth Dr.. Warrendale, PA 15096-0001.
SAE JI 850—Class B Data Corirnunication Network Interface
SAE J2037—Off-Board Diagnostic Message Formats
SAE J2062—A Class B Serial Bus Diagnostic Protocol
SAE J2006—An Appbcation Layer Protocol for a Generic Scan Tool
Once a positive response has been senl by the on-board device, it will wait for a Message 6 from the tester to download code. A second Mode 5 command may be sent to the controller in the case of a garbled acceptance to the tester. The controller should always accept addtionaI Mode 5 requests It currently waiting for a Mode 6 command. Other messages on the data link are allowed for other devices, but the on-board devce will return to normal operation if a message is receid for that device that is not a Mode S or Mode 6 The controller will also return to normal operation if there is no diagnostic test message on the data link for a period of 5 S.
Some systems will execute a monitor program alter accepting the Mode 5 request. Dunng the monitor program, normal software routines will not be executed, and the system may not be updated to atow normal operation. Some provision needs to be made to ensure that the system will operate normally after exiting from thIs monitor. This precaution may requite a system reset to return to a known condition.
7.62 MODE 5 REQUEST
BYTE DESCRIPTION
1.4 Message Header (indudes Mode • 5)
5 Starting Address (High Byte)
6 Starling Address (Low Byte)
7 Number of bytes to be downloaded
7.6.3 MoDe 5 RESPON
BYTE DESCRIPTION
1-4 Message Header (Includes Mode =5)
5 Response Data—Accept $AA
Reject — any other response
7.7 Mode 6—RAM Download and Execute
7.7.1 FuPlcTlo. DESCRIPTION—The RAM Download and Execute message will a’ways follow a RAM Download Request Message 5. The device receiving the message must verity that it can accept a download. This requires that the on-board device has responded to a Message 5 request and Is now ready to accept code. If this condition has not been met, the on-board device should Ignore the download message.
The on-board device will store the code at the address specified in the Mode 5 request message from the test device. At the end of this message, the onboard device should begin executing code at that starting address.
Normally data will be sent back to the test device during program execution. Multiple messages may be returned to the tester, depending on device specific criteria. If this is the case, then one of the data bytes should be used to distinguish between the possible messages. If messages are returned to the tester, then those messages should conform to the general format used in this document.