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I would like to connect OBD2 GPS device in my cars. OBD2 connector support limited OBD protocols. I can't find which protocols present in my cars. So i just want to know what protocol is present in my cars? Below are cars i want to connect my OBD2 device.
I don't have the answer myself, but I may have a way for you to figure it out. I found this page which talks about what is needed for each of the protocols. You may be able to reverse engineer what you have to figure it out. Here's what it says:
OBD-II Protocols
An OBD2 compliant vehicle can use any of the five communication protocols: SAE J1850 PWM, SAE J1850 VPW, ISO9141-2, ISO14230-4 (KWP2000), and since 2003 also ISO 15765-4/SAE J2480. ELM-USB and OBDTester support all of them. Some websites say they support 9 or even more protocols. This is because they mistakenly count protocol variants as separate communication protocols. If you add 4 variants of CAN-BUS to our list, you are on 9.
Please note that some models are equipped with SAE J1962 connector, but these cars are NOT OBD2 compliant. Typical examples of such cars are some early VW/Skoda/Seat models (European versions only), Ford cars with EEC-IV using Ford DCL protocol (e.g. Ford Escort), Nissan EU/Asian models (using Nissan DDL protocol), or some European Hyundai models.
ISO15765-4 (CAN-BUS)
The most modern protocol, mandatory for all 2008+ vehicles sold in the US. Uses pins 6 and 14 (referenced to signal gound), communication is differential.
Four variants of ISO15765 exist. They differ only in identifier length and bus speed:
- ISO 15765-4 CAN (11 bit ID,500 Kbaud)
- ISO 15765-4 CAN (29 bit ID,500 Kbaud)
- ISO 15765-4 CAN (11 bit ID,250 Kbaud)
- ISO 15765-4 CAN (29 bit ID,250 Kbaud)
Fiat/Alfa/Lancia used also fault-tolerant CAN-BUS at 50 kbaud, not compatible with OBD2 standard.
ISO14230-4 (KWP2000)
Very common protocol for 2003+ vehicles using ISO9141 K-Line. Uses pin 7. Two variants of ISO14230-4 exist. They differ only in method of communication initialization. All use 10400 bits per second.
- ISO 14230-4 KWP (5 baud init,10.4 Kbaud)
- ISO 14230-4 KWP (fast init,10.4 Kbaud)
ISO9141-2
Older protocol used mostly on European vehicles between 2000 and 2004. Uses pins 7 and optionally 15.
SAE J1850 VPW
Diagnostic bus used mostly on GM vehicles. Uses pin 1, communication speed is 10.4 kB/sec.
SAE J1850 PWM
Diagnostic bus/protocol used mostly on Ford. Uses pins 1 and 2, communication signal is differential and it's rate is 41.6kB/sec.
Determining protocol from OBD-2 pinout
Standard Pin 2 Pin 6 Pin 7 Pin 10 Pin 14 Pin 15 J1850 PWM must have - - must have - - J1850 VPW must have - - - - - ISO9141/14230 - - must have - - optional ISO15765 (CAN) - must have - - must have -
Please note that other pins may also be fitted. They usually connecto to other (non-engine) ECUs or provide various signals. Generic OBD2 tools are not capable of "talking" to other ECUs than engine. For diagnosis of other control units such as ABS, airbag, audio or body modules you need vendor-specific software such as FiCOM (Fiat/Alfa/Lancia), FoCOM (Ford/Mazda) or HiCOM (Hyundai/Kia).
Other non-OBD2 protocols
Almost every car uses also vendor-specific diagnostic protocols such as KWP2000, KW1281, VWTP, KW72, KW82, which are used for "native" diagnostics.
You can buy a cheap mini Bluetooth scanner ($5) and see if it connects automatically. If it does, it should be OBDII compliant. If you still want to know the exact protocol, connect with a Bluetooth serial terminal app and send the command ATDP, which will respond with the name of the protocol being used.
There is a new protocol- SAE J1939 - the Data link connector standard, that is supported by new WiFi Scan tools - code readers like Vgate iCar. SAE J1939 is the vehicle bus (specialized internal communications network) recommended practice used for communication and diagnostics among vehicle components.
