1、SURFACE VEHICLE RECOMMENDED PRACTICE J1699-4 APR2014 Issued 2014-04 OBD-II Communications Anomaly List RATIONALE This information report has been issued to promote awareness of SAE J1979 OBD communications anomalies that may be encountered during the course of normal communication attempts between v
2、ehicle emission OBD ECUs and Diagnostic Equipment. FOREWORD The SAE J1699-4 Task Force, a member of SAE E/E Diagnostics Steering Committee, has created this document to serve as a guide to common anomalies which may affect OBD communication using SAE J1850VPW, SAE J1850PWM, ISO 9141-2, ISO 14230-4,
3、or ISO 15765-4 protocol between vehicle emission OBD ECUs and Diagnostic Equipment that utilizes generic services defined in SAE J1979. Content of this document includes actual failures confirmed by investigation of actual vehicle units-in-operation, review and clarification of recommended practice
4、documentation, and implementation guidance required to enable diagnosis on early model vehicles so that diagnostic equipment can obtain generic data content from vehicle systems that may have been released to the field with anomalous behavior. Guidance in this document may not be compliant with curr
5、ently published ISO or SAE Standards or Recommended Practices. Content within this document may also include items which have been the subject of misinterpretation of said Standards or Recommended Practices. TABLE OF CONTENTS 1. SCOPE 2 1.1 Purpose . 2 2. REFERENCES 2 2.1 Applicable Documents 2 2.2
6、Related Publications . 3 3. DEFINITIONS . 4 4. OVERVIEW . 4 4.1 Documentation Conventions . 4 _ 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 applica
7、bility and suitability for any particular use, including any patent infringement arising therefrom, is the sole responsibility of the user.” SAE reviews each technical report at least every five years at which time it may be revised, reaffirmed, stabilized, or cancelled. SAE invites your written com
8、ments and suggestions. Copyright 2014 SAE International All rights reserved. No part of this publication may 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
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10、al/standards/J1699/4_201404 SAE INTERNATIONAL J1699-4 Issued APR2014 Page 2 of 9 5. COMMUNICATIONS ANOMALIES 5 5.1 Physical address assignments for legislated emission ECUs. . 5 5.2 Incorrect Header Bytes supported by Vehicle ECU. . 5 5.3 Incorrect Header Bytes supported by Diagnostic Equipment. 6 5
11、.4 K-Line Initialization 6 5.5 Erratic vehicle response to Service $01 PID $00 requests. 7 5.6 Response Order for Multiple Emission ECUs. 7 5.7 SAE J1850 Timing Issues. 8 5.8 Sleeping Diagnostic CAN Bus. . 8 5.9 Multiple Frame Responses on ISO 15765-4 CAN 8 5.10 Physical Addressing to Emission ECUs
12、on ISO 15765-4 Protocol is Not Allowed . 8 5.11 Incorrect Key Bytes supported by Vehicle ECU. 9 6. NOTES 9 6.1 Marginal Indicia . 9 1. SCOPE To define a list of anomalies related to OBD Communications. Misinterpretations of various OBD Communications Standards and Recommended Practices have resulted
13、 in OBD “no-communications” situations in the field. This Information Report identifies the most prevalent of these. 1.1 Purpose To provide guidance to diagnostic equipment (handheld scan tools, vehicle communication interfaces, inspection software systems) manufacturers, Vehicle OEMs, and Governmen
14、t Regulation authorities (CARB, EPA, etc.) in identifying issues with OBD Communications. 2. REFERENCES 2.1 Applicable Documents The following publications form a part of this specification to the extent specified herein. Unless otherwise indicated, the latest issue of SAE publications shall apply.
15、2.1.1 SAE Publications Available from SAE International, 400 Commonwealth Drive, Warrendale, PA 15096-0001, Tel: 877-606-7323 (inside USA and Canada) or 724-776-4970 (outside USA), www.sae.org. SAE J1850 Class B Data Communications Network Interface SAE J1930 Electrical/Electronic Systems Diagnostic
16、 Terms, Definitions, Abbreviations, and Acronyms - Equivalent to ISO/TR 15031-2 SAE J1978 OBD II Scan Tool - Equivalent to ISO/DIS 15031-4:December 14, 2001 SAE J1979 E/E Diagnostic Test Modes SAE J2012 Diagnostic Trouble Code Definitions SAE J2178-1 Class B Data Communication Network Messages - Det
17、ailed Header Formats and Physical Address Assignments SAE INTERNATIONAL J1699-4 Issued APR2014 Page 3 of 9 2.1.2 ISO Publications Available from American National Standards Institute, 25 West 43rd Street, New York, NY 10036-8002, Tel: 212-642-4900, www.ansi.org. ISO 9141-2 Road vehicles Diagnostic s
18、ystems Part 2: CARB requirements for interchange of digital information ISO 14230-4 Road vehicles Diagnostic systems Part 4: KWP 2000 requirements for emission related systems ISO/DIS 15031-2 Communication Between Vehicle and External Equipment for Emissions-Related Diagnostics Part 2: Terms, defini
19、tions, abbreviations and acronyms (Equivalent to SAE J1930) ISO/DIS 15031-3 Communication Between Vehicle and External Equipment for Emissions-Related Diagnostics Part 3: Diagnostic connector and related electrical circuits, specification and use (Equivalent to SAE J1962) ISO/DIS 15031-4 Communicati
20、on Between Vehicle and External Equipment for Emissions-Related Diagnostics (Equivalent to SAE J1978) ISO/DIS 15031-5 Communication Between Vehicle and External Equipment for Emissions-Related Diagnostics Part 5: Emissions-related diagnostic services (Equivalent to SAE J1979) ISO/DIS 15031-6 Communi
21、cation Between Vehicle and External Equipment for Emissions-Related Diagnostics Part 6: Diagnostic trouble code definitions (Equivalent to SAE J2012) ISO 15765-4 Road vehicles Diagnostics on Controller Area Network (CAN) Part 4: Requirements for emissions-related systems 2.2 Related Publications The
22、 following publications are provided for information purposes only and are not a required part of this SAE Technical Report. 2.2.1 SAE Publications Available from SAE International, 400 Commonwealth Drive, Warrendale, PA 15096-0001, Tel: 877-606-7323 (inside USA and Canada) or 724-776-4970 (outside
23、USA), www.sae.org. SAE J1699-1 SAE J1850 Verification Test Procedures. SAE J1699-2 OBD II Related SAE Specification Verification Test Procedures SAE J1699-3 OBD II Compliance Test Cases. 2.2.2 ISO Publications Available from American National Standards Institute, 25 West 43rd Street, New York, NY 10
24、036-8002, Tel: 212-642-4900, www.ansi.org. ISO 11898 Road vehicles, Interchange of Digital information, Controller Area Network (CAN) for High Speed Communication. ISO 14229 - Road Vehicles, Diagnostic Systems, Specification of Diagnostic Services. 2.2.3 Other Publications CARB Regulation Title 13,
25、California Code Regulations, Section 1968.2, Malfunction and Diagnostic System Requirements for 2004 and Subsequent Model-Year Passenger Cars, Light-Duty Trucks, and Medium-Duty Vehicles and Engines (OBD II). Web address: SAE INTERNATIONAL J1699-4 Issued APR2014 Page 4 of 9 3. DEFINITIONS 3.1 Defini
26、tion of Terms The definitions of terms that are related to the use of this document may be found in the publications listed under Section 2.1, Applicable Publications. 3.2 Acronyms The following are common acronyms used in this document: Addr Address CALID Calibration Identification CAN Controller A
27、rea Network CVN Calibration Verification Number CARB California Air Resources Board ECU Electronic Control Unit EMC Electromagnetic Compatibility I/M Inspection and Maintenance ISO International Standards Organization INFTYP Infotype KWP Key Word Protocol OBD-II On Board Diagnostics (level 2) PDU Pr
28、otocol Data Unit PID Parameter Identification (number) SAE Society of Automotive Engineers VIN Vehicle Identification Number 4. OVERVIEW This document defines known anomalies that may occur during tester to vehicle OBD Communications. 4.1 Documentation Conventions All references to protocol specific
29、 parameters that are specified in other documents will be in italics (for example, W0). SAE INTERNATIONAL J1699-4 Issued APR2014 Page 5 of 9 5. COMMUNICATIONS ANOMALIES This section provides a list of known anomalies that create issues during I/M testing. 5.1 Physical address assignments for legisla
30、ted emission ECUs. 5.1.1 Problem Definition: SAE J2178-1, Table 11, defines suggested ranges of physical address assignments for different ECU types (e.g., address range $10-17 for engine, address range $18-1F for transmission) to be used in the header bytes of all SAE J1979 emission-related message
31、s for Class B Communications. For all CARB approved legislated protocols except ISO 15765-4 11-bit CAN, past vehicle implementations have largely adhered to using the ECU address ranges as specified in SAE J2178-1. However, a small amount of ECUs use physical addresses which have been out of this ra
32、nge. 5.1.2 Suggested Guidance 1: diagnostic equipment manufacturers should reference the following table of known “out of range per SAE J2178-1” ECU addresses which are known to be used by emission ECUs. When the Diagnostic equipment is performing tester to ECU communications per SAE J1979 emission
33、related messaging scenarios, the list of ECUs shown below should be included as address exceptions. Address ECU Range ECU Description $00 Engine Engine control module $01 Engine Engine control module $0D Engine Engine control module $0E Engine Engine control module $0F Engine Engine control module $
34、22 Engine Power/idle control module $32 Transmission Transmission control module $40 Engine Engine control module $41 Transmission Transmission control module $64 Engine Engine control module $D1 Engine Engine control module $E8 Engine Engine control module TABLE 1 OUT OF RANGE PER SAE J2178-1 ECU A
35、DDRESSES 5.1.3 Suggested Guidance 2: vehicle OEMs, network engineers, and ECU developers should reference SAE J2178-1, Table 11 and ISO 15765-4 “29-bit legislated-OBD CAN identifiers recommendation” when assigning ECU addresses. 5.2 Incorrect Header Bytes supported by Vehicle ECU. 5.2.1 Problem Defi
36、nition: after receiving a correctly formatted diagnostic equipment message request (as defined in Figure 11 of SAE J1979), the vehicle ECU responds with a message which contains incorrect header bytes. For example, after a diagnostic equipment request, an ECU incorrectly responds with a “68 (or 61)
37、6B addr“. Diagnostic equipment programmed to reject all messages from the ECU that do not conform to “48 (or 41) 6B addr“ definition in Figure 1 of SAE J1979 may be unable to communicate to one or more of the ECUs on the vehicle. 5.2.2 Suggested Guidance 1: vehicle OEMs should review their ECU softw
38、are implementation plans (which meet specification set forth in SAE J1979 document) to ensure that header bytes are properly programmed into the ECU communication handler software per Figure 11 of SAE J1979. Depending on the protocol, given a diagnostic equipment request message header of “68 (or 61
39、) 6A Fx“ an ECU response message shall be header bytes of “48 (or 41) 6B ECU_addr“. 5.2.3 Suggested Guidance 2: for SAE J1850 VPW and PWM, and ISO 9141-2 protocols, diagnostic equipment manufacturers should not program their tools to reject all messages that do not conform to “48 (or 41) 6B ECU_addr
40、“. SAE INTERNATIONAL J1699-4 Issued APR2014 Page 6 of 9 5.3 Incorrect Header Bytes supported by Diagnostic Equipment. 5.3.1 Problem Definition: after initialization, some diagnostic equipment request SAE J1979 service $01 data using improper header bytes on the K-Line data bus. For example, during t
41、ester to ECU initialization, an ECU may have identified itself as supporting ISO 14230-4 protocol using $8F KB2 ($E9, $6B, $6D, $EF) key bytes. In this case, regardless of the returned key byte value(s), some diagnostic equipment will utilize a Service $01 PID $00 request message of $68 6A F1 01 00
42、C4 (this message is not correct for the identified protocol of ISO 14230-4). 5.3.2 Suggested Guidance 1: diagnostic equipment manufacturers should adhere to the following key byte to message table after reading the ECUs key byte indication and before sending a Service $01 PID $00 request on the K-Li
43、ne: Init Type To Address Returned Key Bytes from ECU Indicate Protocol Header Byte Example: Service $01 PID $00 Request 5 Baud $33 $08 08 or $94 94 ISO 9141-2 $68 6A F1 01 00 C4 5 Baud $33 $8F E9 or $8F 6B or $8F 6D or $8F EF ISO 14230-4 $C2 33 F1 01 00 E7 Fast $33 (Use StartComm message) $8F E9 or
44、$8F 6B or $8F 6D or $8F EF ISO 14230-4 Fast Init $C2 33 F1 01 00 E7 TABLE 2 EXAMPLE OF HEADER BYTES ON K-LINE PROTOCOLS 5.3.3 Note: the protocol determination process presented in this section applies to SAE J1979 services when requests for data are being performed on a K-line. 5.3.4 Some vehicles m
45、ay require tighter timings for TiniL, as little as 25+/- 0.1 ms, rather than the standard 25 +/- 1ms timing given in ISO 14230-2. 5.4 K-Line Initialization 5.4.1 Problem Definition: many diagnostic software initialization errors stem from the fact that attempts at K-Line protocol initialization are
46、performed without taking into account the three unique methods of initializing ECUs on a K-line network. Examples of incorrect diagnostic equipment software behavior include attempting a fast initialization, then attempting a 5-baud initialization without waiting for any 5-baud modules to recover fr
47、om the preceding low transition of the K-Line (Recommended to wait 2.6sec for sum of A1(2sec) + W1(300ms) + W5(300ms) to expire). As ECUs developed in a pre-KWP2000 time frame will not recognize KWP initialization and command structures, other conditions may occur due to a misunderstanding of CARB r
48、egulations and specification content outlined in SAE J1979, SAE J1978, and SAE J1699-3 documents. Three OBD Communications protocols are defined on the K-Line: 5.4.1.1 ISO 9141-2 this is identified by the use of a 5-baud initialization utilizing the keywords $08 08 or 94 94. Industry may also refer
49、to this initialization method as “CARB-mode.” 5.4.1.2 ISO 14230-4 with 5-baud initialization also known as KeyWord Protocol 2000 (KWP2000) with 5-baud initialization. ISO 14230-4 5-baud initialization is differentiated from ISO 9141-2 5-baud initialization by the use of keywords 8F E9, 8F 6B, 8F 6D, or 8F EF. Only the functionality of keyword 8F E9 is allowed for OBD communications SAE INTERNATIONAL J169
