Vehicles that are made in 1996 or later are required by law to have an OBD2 system, which lets you communicate with your vehicle to ensure the vehicle works well.
Each car contains a DLC (Data Link Connector) which is to make a connection between the car and the scanner. Known as the OBD2 protocol, this system is important to form a connection.
A vehicle can have one out of two OBD2 protocols, A or B. They differ in terms of the number of connectors or pins they have.
Let’s get to know about the five types of OBD2 protocols.
Table of Contents
Types of OBD2 protocols
Below, you will find OBD2 protocols by vehicle make and model:
SAE J1850 PWM
Connectors with pins 2 and 10 are SAE J1850 PWM protocol. It operates at 41.6 kb/sec and is mostly found in Ford vehicles. The signal produced by it is Pulse Width Modulation.
SAE J1850 PWM must have pins 2, 4, 5, 10, and 16.
SAE J1850 VPW
This protocol is found in GM vehicles. It works at a speed of 10.4 kb/sec with variable pulse width.
SAE J1850 VPW must have pins 2, 4, 5, and 16. The biggest difference between VPW and PWM is that this OBD2 protocol has no pin 10.
Next, ISO 9141-2 is an old protocol that is mostly found in European vehicles that were built between 2000 and 2004. You will find this protocol on some Chrysler and Asian vehicles as well.
It uses pin 7 and pin 15 is optional (pin 4, 5, and 16 are must-haves). The operating speed is 10.4 kb/sec and this protocol uses asynchronous serial communication.
ISO 9141-2 protocol
ISO 14230 KWP2000
It works on an asynchronous serial communication method that operates at 10.4 kbps per second.
This type of protocol is found in Asian vehicles or in 2003+ vehicles that have a pin 7 ISO 9141 K-Line while pin 15 is optional. It’s also commonly used in Chrysler and most European models.
Because it is similar to the ISO 9141-2 protocol (the same pins), you may have difficulty identifying this OBD2 protocol.
ISO 15765-4 CAN (SAE J2480)
Lastly, the ISO 15765-4 CAN is found in modern vehicles (US) that are built in 2008 or later.
This protocol must have pins 4, 5, 6, 14, and 16.
Furthermore, this OBD2 protocol has 4 variants:
- ISO 15765-4 CAN (250 Kbaud, 11 bit ID)
- ISO 15765-4 CAN (250 Kbaud, 29 bit ID)
- ISO 15765-4 CAN (500 Kbaud, 29 bit ID)
- ISO 15765-4 CAN (500 Kbaud, 11 bit ID)
It works on a two-wire communication method and can handle up to 1 Mbps.
What are the ways to check my OBD2 protocol?
OBD2 protocols: Must-have pins for the connector
|OBD2 Protocol||Pin 2||Pin 6||Pin 7||Pin 10||Pin 14||Pin 15|
|ISO 15765 CAN||✔️||✔️|
|ISO 9141||✔️||✔️ (Optional)|
|ISO 14230 KWP2000||✔️||✔️ (Optional)|
The easiest way to identify an OBD2 protocol is to look at the alignment and availability of the pins.
Here’s what you need to focus on:
- If there are pins 2 and 10 in the connector with metallic pins 2, 4, 5, 10 and 16 then it’s a J1850 PWM protocol.
- If you can see pin 2 and material contacts inside pins 2, 4, 5, and 16 but there’s no PIN 10 then it’s a J1850 VPW protocol.
- If the connector has pin 7 and an optional pin 15 then it could be ISO 9141 or ISO 14230 KWP2000. The metallic contacts inside the pins are 4, 5, 7, 15, (plus 16).
- If there are both pins 14 and 6 in a connector with material contacts 4, 5, 6, 14 and 16 then it’s an ISO 15765 CAN protocol.
Which OBD2 protocol is supported by my vehicle?
You can examine OBD2 connector pins to find out which protocol is supported by your vehicle.
- OBD2 connector types
Type A: This type of OBD2 protocol has 16 teeth altogether, 8 on the upper row and 8 on the bottom. It seems as if it’s “Sandwiching a Tongue”. This protocol is a female plug with a D-shape look.
Type A protocols are found in 12V vehicles.
Type B: This one has 16 teeth as well but it’s a bit different from Type A protocol. It has a disrupted groove in the center which restricts a Type A male connector from sitting in it. However, you can plug a type B male plug into a type A female plug.
In appearance, it looks quite like Type A but there’s one notable difference – the sandwiching of Tongue is split into two.
Type B protocols are found in 24V vehicles.
- OBD2 connector pins interpretation
Since we know that every connector has 8 upper rows and 8 lower rows, let’s find out what each pin is meant for.
Pins on the upper row
Pin 1: It is used for OEM COMM.
Pin 2: J1850 Bus+ is found here.
Pin 3: OEM Reserved.
Pin 4: Framework/car chassis ground.
Pin 5: Holds sensor signal ground.
Pin 6: Most of the modern cars have OEM COMM pins. It also contains pins 4, 5, 6, 15, and 16.
Pin 7: It denotes the K-line.
Pin 8: OEM Reserved.
Pins at the bottom row
Pin 9: OEM COMM.
Pin 10: A J1850 Bus- (negative) is found on this pin.
Pin 11–14: OEM Reserved
Pin 15: ISO 9141-2 L-line.
Pin 16: This pin powers the adapter.
We hope this information will help you identify your vehicle’s OBD2 protocol. It can be a bit difficult since they all look the same but you will get it if you pay attention to the design and pins.