1、_ SAE Technical Standards Board Rules provide that: “This report is published by SAE to advance the state of technical and engineering sciences. The use of this report is entirely voluntary, and its applicability and suitability for any particular use, including any patent infringement arising there
2、from, is the sole responsibility of the user.” SAE reviews each technical report at least every five years at which time it may be reaffirmed, revised, or cancelled. SAE invites your written comments and suggestions. Copyright 2007 SAE International All rights reserved. No part of this publication m
3、ay be reproduced, stored in a retrieval system or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of SAE. TO PLACE A DOCUMENT ORDER: Tel: 877-606-7323 (inside USA and Canada) Tel: 724-776-4970 (outside USA)
4、 Fax: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS: http:/www.sae.org J2809 ISSUED OCT2007 SURFACE VEHICLE INFORMATION REPORT Issued 2007-10 Honda Diagnostic Serial Data Link ProtocolABS/VSA System RATIONALE Not applicable. TABLE OF CONTENTS 1. SCOPE 2 2. REFERENCES 2 2.1 Applicable Pu
5、blications . 2 2.1.1 SAE Publications. 2 2.1.2 ISO Publications 2 3. DEFINITIONS AND ACRONYMS. 2 4. OVERVIEW. 3 4.1 Telegram-Specific Overview. 3 4.2 Message-Specific Overview 5 4.3 Acknowledge/No Acknowledge Message. 6 5. INTERFACE 6 6. INITIATION OF SERIAL DIAGNOSIS, ADDRESS WORD 7 6.1 Stimulation
6、 of the ABS/VSA Control Unit 7 6.2 Communication Set-Up. 8 6.3 Error Handling During Communication Setup. 10 7. COMMUNICATION. 10 7.1 Message Structure 10 7.1.1 Message Length 11 7.1.2 Message Counter 11 7.1.3 Message Title 11 7.1.4 Message-Specific Bytes 11 7.1.5 Message End Byte 11 7.2 Data Protec
7、tion . 11 7.3 Error Handling During Normal Communication 12 7.4 Telegram Structure . 13 7.5 Function Sequence . 14 Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE J2809 Issued OCT2007 - 2 - 1. SC
8、OPE This Technical Information Report defines the proprietary diagnostic communication protocol for ABS or VSA ECU (Electronic Control Unit) implemented on some Honda vehicles. This protocol does not apply to all Honda vehicles. This document should be used in conjunction with SAE J2534-2 in order t
9、o fully implement the communication protocol in an enhanced SAE J2534 interface. The purpose of this document is to specify the requirements necessary to implement the communication protocol in an enhanced SAE J2534 interface. 2. REFERENCES 2.1 Applicable Publications The following publications form
10、 a part of this specification to the extent specified herein. Unless otherwise indicated, the latest version of SAE publications shall apply. 2.1.1 SAE Publications Available from SAE, 400 Commonwealth Drive, Warrendale, PA 15096-0001, Tel: 877-606-7323 (inside USA and Canada) or 724-776-4970 (outsi
11、de USA), www.sae.org. SAE J2534-1 Recommended Practice for Pass-Thru Vehicle Programming SAE J2534-2 Optional Pass-Thru Features 2.1.2 ISO Publications Available from ANSI, 25 West 43rd Street, New York, NY 10036-8002, Tel: 212-642-4900, www.ansi.org. ISO 9141:1989 Road vehiclesDiagnostic systemsReq
12、uirements for interchange of digital information ISO 9141-2:1994 Road vehiclesDiagnostic systemsCARB requirements for interchange of digital information 3. DEFINITIONS AND ACRONYMS 3.1 “ABS” Anti-lock Brake System. 3.2 “VSA” Vehicle Stability Assist. 3.3 “Serial Diagnosis” The serial diagnosis offer
13、s the possibility of rapid access to control unit information and functions without disconnecting the wire harness. Serial diagnosis allows interrogation of all input signals present at the control unit, external switching of all actuators to which the control unit has access as well as reading the
14、internal unit information such as the fault memory. Serial diagnosis can be used in the end of line inspection or in the service workshops and can contribute towards considerable savings in inspection time. Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproducti
15、on or networking permitted without license from IHS-,-,-SAE J2809 Issued OCT2007 - 3 - 3.4 “MESSAGE” The smallest repeatable unit of transmission is a “MESSAGE”. A message consists of a certain number of bytes and always has the same format. 3.5 “TELEGRAM” The sum of all messages transmitted during
16、communication with a control unit is a “TELEGRAM”. 3.6 “TRANSMITTER” The unit (control unit or tester) which is entitled to output a message is called a “TRANSMITTER”. 3.7 “RECEIVER” The transmitter executes a passive handshake (i.e. it checks the complemented byte with respect to correct transmissi
17、on). The receiver of a message is called a “RECEIVER”. The receiver performs an active “handshake” (each received byte (except “ETX”) is complemented and returned to the transmitter). 4. OVERVIEW 4.1 Telegram-Specific Overview FIGURE 1 - INITIATION OF DIAGNOSIS Copyright SAE International Provided b
18、y IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE J2809 Issued OCT2007 - 4 - FIGURE 2 - COMMUNICATION TELEGRAM Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted with
19、out license from IHS-,-,-SAE J2809 Issued OCT2007 - 5 - 4.2 Message-Specific Overview FIGURE 3 - MESSAGE TRANSMISSION Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE J2809 Issued OCT2007 - 6 - TA
20、BLE 1 - TIMING PARAMETERS Description Parameter Name Minimum Value Maximum Value Stimulation Idle line before start of stimulation t010 msec Start of Communication Time between correct stimulation and start of the synchronization byte t1200 msec 400 msec Time between synchronization byte and key-byt
21、e 1 t220 msec 200 msec Time between key-byte 1 and key-byte 2 t31 msec 200 msec Time between key-byte 2 and complement key-byte 2 t41 msec 200 msec Time between key-byte 2 and the renewed output of the synchronization byte (If complement key-byte 2 incorrectly received by control unit) t5200 msec 1
22、sec Time between key-byte 2 and start of ECU identification t61 msec 200 msec During Communication Time between bytes within a message (i.e. between a byte from the transmitter and its complement from the receiver) t71 msec 40 msec For the Receiver: the minimum time the receiver waits before sending
23、 the response if ETX is lost (i.e. it starts receiving retried message if the first byte of the message is received within t8). Note: ETX is not required to be received by the Receiver. t8N/A 80msec Time between end of a message and start of the next message t91 msec 2 sec 4.3 Acknowledge/No Acknowl
24、edge Message Request Message Control Unit Response Message Title Request Response Title Number of Messages 0x09 Acknowledge Acknowledge 0x09 1 0x0A No acknowledge Repeat last message 1 5. INTERFACE The ABS/VSA control unit requires one line for communication with an external tester, the bi-direction
25、al communication line (K line). This line possesses bus capability, i.e. it can be connected together with lines with the same function from other control units (see Figure 4). Activation of a control unit on the diagnosis bus by the tester takes place by means of an address specific to the control
26、unit which is transmitted via the bi-directional line (K line). Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE J2809 Issued OCT2007 - 7 - FIGURE 4 - DIAGNOSIS CONNECTION CONCEPT 6. INITIATION OF
27、 SERIAL DIAGNOSIS, ADDRESS WORD 6.1 Stimulation of the ABS/VSA Control Unit The ABS/VSA control unit is selected from all control units connected to the diagnosis bus for a subsequent communication by the means of stimulation by the tester. Stimulation takes place by transmission of the address word
28、 assigned to the ABS/VSA control unit. In normal mode, stimulation can occur only when the vehicle is at a standstill with a speed below the diagnosis limit speed and with the ignition switched on. If the control unit is in the failure mode (valve relay switched off), stimulation is accepted at any
29、speed. In order to access diagnosis mode, the address word must first be transmitted via the K line. The address word used for stimulation must be transmitted in 10-bit format at a transfer rate of 5 baud 0.5%. Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reprod
30、uction or networking permitted without license from IHS-,-,-SAE J2809 Issued OCT2007 - 8 - The address word is made up as follows, in the order of transmission (see Figure 5): 1 start bit (logical “0”, low potential, reaction of control unit to 1-0 transition) 7 data bits (ECU-specific address), sta
31、rting with the LSB 1 parity bit (parity odd) 1 stop bit (logical “1”, high potential) The control unit aborts stimulation detection if wheel speed limit diagnosis speed = 2.75 km/h no valid stop bit recognized wrong parity recognized no valid start bit recognized received address not same as own add
32、ress After abortion of stimulation detection, the control unit synchronizes itself to a stimulation operating again, whereby this can be repeated an arbitrary number of times by the tester. FIGURE 5 - ADDRESS WORD The ABS/VSA function is no longer available after completion of a valid stimulation op
33、eration. The control unit is then in the diagnosis mode. During the diagnosis mode, the monitoring routines for the control unit peripherals required for the ABS/VSA function are processed only to a restricted extent. The ABS/VSA safety lamp is activated continuously during the diagnosis. 6.2 Commun
34、ication Set-Up Communication is set up on the basis of the existing ISO 9141 specification. After the control unit has received the stop bit of the address word which has been identified as its own address, it waits for 1 bit duration of the stimulation word in order to give the tester an opportunit
35、y to prepare itself for a subsequent communication. After this waiting time, the control unit reacts with output of a synchronization byte on the K line. The reaction takes place within a time of t1, calculated from complete reception of the stimulation address stop bit. Copyright SAE International
36、Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE J2809 Issued OCT2007 - 9 - The synchronization byte has the following structure (see Figure 6): 1 start bit (logical “0”, low potential) 8 data bits (content = 0x55, starting
37、with the LSB) 1 stop bit (logical “1”, high potential) FIG. 6 - SYNCHRONIZATION BYTE The synchronization byte is transmitted with the same baud rate as is used for subsequent data transfer. The tester can recognize the baud rate on the basis of the synchronization byte (e.g. by measurement of the in
38、tervals between the falling edges). 2 key-bytes are transmitted after the synchronization byte. These inform the tester of the parameters for subsequent communication. The key-bytes have the following structure (See Figure 7). 1 start bit (logical “0”, low potential) 7 Key data bits 1 parity bit (od
39、d parity) 1 stop bit (logical “1”, high potential) The 2 key-bytes must be considered as belonging together and represent a 14-bit piece of information. The low byte = 0xAB is transmitted first, followed by the high byte = 0x02. Keyword information: 299 (P000 0010 P010 1011 B) Keyword Low High Witho
40、ut parity 0x2B (010 1011B) 0x02 (000 0010B) With parity 0xAB (1010 1011B) 0x02 (0000 0010B) FIGURE 7 - KEYWORD Following transmission of the synchronization byte, the control unit waits for t2before transmitting the first key-byte. This allows the tester sufficient time to change its baud rate to th
41、at measured from the synchronization byte. Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE J2809 Issued OCT2007 - 10 - The 2 key-bytes are transmitted at an interval of t3. After output of the se
42、cond key-byte, the control unit expects the complement of the second key-byte from the tester as confirmation of successful communication, whereby the tester must observe an interval of t4before it sends the complement. This interval serves the purpose of allowing the control unit sufficient time to
43、 switch over to receive mode. After successfully completing the communication setup, the control unit starts with the first byte of the ECU ID message after a time of t6. During communication, the ABS/VSA control unit operates with the following data format (see Figure 8): 1 start bit (logical “0”,
44、low potential) 8 data bits No parity 1 stop bit (logical “1”, high potential) FIGURE 8 - DATA FORMAT 6.3 Error Handling During Communication Setup If the control unit recognizes the complement of the key-byte as containing an error, then it can assume that the tester has not correctly determined the
45、 baud rate of the synchronization byte. The control unit waits for t5before it starts with renewed output of the synchronization byte so that the tester experiences a time-out and also detects an error. In the event of a fault, communication setup can be performed once more without renewed stimulati
46、on. A time-out representing approximately 1 bit period of the stimulation word (200 msec) is used for detection of a fault. This means that the interval between 2 bytes during communication setup must never be longer than the time corresponding to the time-out. If a tester time-out occurs during com
47、munication setup, the tester can assume that the control unit (if it is still capable of functioning) will start communication setup again with output of the synchronization byte, unless the number of communication setup repetitions programmed in the control unit has been reached. If a control unit
48、time-out occurs, which can happen only if the control unit does not receive the complement of the second key-byte, it reacts with output of the synchronization byte after the time-out, as mentioned above. 7. COMMUNICATION 7.1 Message Structure The information which is exchanged between the tester and the control unit is combined in messages on the basis of the respective content. All Messages have the same message structure. Each message consists o
