开发人员不可不看的 OBD通讯协议知识

时间:2013-01-13  来源:车联网周刊   作者:车联网周刊   点击:

OBD-II Network Standards
» J1850 VPW
– Adopted by GM; also known as Class 2.
– Adopted by Chrysler (known as J1850).
– Some references to VPW mode heard about in regards to Toyota (and Honda ?).
– 10.4 kbps, single wire.
» J1850 PWM
– Adopted by Ford; also known as Standard Corporate Protocol (SCP).
– Also seen in some Mazda products.
– Some references to PWM mode heard about in regards to Mitsubishi.
– 41.6 kbps, two wire balanced signal.
» ISO 9141 and ISO 9141-2 (also known as ISO 9141 CARB)
– Seen in some Chrysler and Mazda products.
– Seems to be more common in Europe.
– 10.4 kbps, single wire.
OBDII 通讯协议
obdii generic communication protocols by manufacturer
Recently I tried to install my product on Peuzeot(406 or something
similar). There was
KWP 2000 bus. I tried to get the speed value from the bus by sending
the following string
0xc2 0x33 0xf1 0x01 0x0d 0xf4.
On responce I received two answers from 2 different ECUs:
1) 0x83 0xf1 0x10 0x7f 0x01 0x12 0x16
1) 0x83 0xf1 0xa4 0x41 0x0d 0x00 0x66

The first ECU sent me NACK
(This response code indicates that the requested action will not be
taken because the server (ECU) does not support the arguments of the
request message or the format of the argument bytes do not match the
prescribed format for the specified service.)

My question is: if there was something wrong with the arguments of the
request message, the second ECU also should not understand the
request, bit it did !
And the second question is: why the first ECU did send the negative
answer. If you look at the j1979 PDF you will find there that "If an
ECU does not support any of the PIDs requested it is not allowed to
send a negative response message".
OBD 信息: obd-ii标准诊断插座列表

OBD-II通讯协议(如何知道汽车使用的哪一种) - 何正茂 - autolife爱汽车 爱生活
    端子号称         端子接线
---------------------------------------------------------------------
4         搭铁
16        蓄电池正极,9-12v
7,15     资料数据传输线(iso 9141-2)
5         信号反馈线搭铁
2         sae j1850数据输送线
10        sae制造厂数据输送线
举一实例;捷达前卫诊断座t16中;就有16 4 7三个端子按以上要求接线。
EOBD 欧洲标准
新的 european obd 诊断坐连接标准 dlc-j1962
================================================================================
pin 1 ......sae j2411, gm single wire can;通用公司单线 can-bus
pin 2 ......iso 11519-4 (bus+)(sae j1850), 和10号脚同时使用, 41.6 kbps pwm脉宽调制
单线用法:只用2号脚1根线通讯10.4 kbps vpw可变脉宽调制 byte header + crc,
no "checksum" or "inter-byte separation" (in frame response byte ?)
pin 3 ...... chrysler, ccd+ (not obd) ;克莱斯勒 ccd-bus网线 h 线
pin 4 ...... 底盘地 chassis ground
pin 5 ...... 逻辑地 signal ground
pin 6 ...... iso 15765-4;can-bus 高速诊断线 (h 线) ,250/500 kbit/s
pin 7 ....... kwp1281或kwp2000 协议诊断线 (k线), 波特率10400/多数厂家默认kpw2000诊断线
pin8 ........ 点火开关打开有电 ig+;点火开关 on/off 状态识别用途
pin9 ........ 7号脚不方便用时,启用*kwp1281或kwp2000 协议诊断线 (k线), 波特率10400
pin10 ....... iso 11519-4 (bus-)(sae j1850), 和 2号脚同时使用, 41.6 kbps pwm脉宽调制
pin 11 ...... chrysler, ccd- (not obd) ;克莱斯勒 ccd-bus网线 l 线
pin 12 ...... * k 线 制造厂保留用
pin 13 ...... * k 线 制造厂保留用
pin 14 ...... iso 15765-4;can-bus 高速诊断线 (l 线) ,250/500 kbit/s
pin 15 ...... kwp1281或kwp2000 协议诊断线 (k线);7p不够用或控制单元过多时启用
pin 16 ...... 长火线 bat+

obdii和eobd的基本区别

功能 obdii eobd
进行燃油箱及燃油系统的泻漏试验
探测发动机不(发)点火的转速到 最大 4500r/min
故障发生经历多少个驾驶周期故障指示灯才闪亮 2 2-10
用故障指示灯显示汽车行驶距离
使用的通讯协议 sae j1850 iso 9141-2
(责任编辑:)