OBD Help

People often write asking where they can get more OBD information, or for help in making their circuits, etc. These OBD help sections provide answers to most of the common questions that we receive. Perhaps the most popular question of all is:

What OBD (On Board Diagnostics) protocol does my car use?

There is a chance that your car may not use any OBD protocol. Many vehicles are able to communicate with some form of scan tool, but may not use an OBDII protocol (which is what ELM ICs support). If your car is older, or from a country that does not require OBD, then your car may not respond to OBD requests for data.

A vehicle’s ability to communicate using OBDII really depends on the age of the vehicle, and the market that it was manufactured to be sold in. It is difficult for us to provide an accurate table of this data for you, as most countries set a date for full compliance, and also provide a ‘phase-in’ period in which the OBD requirements increase over time. Some do not publish their requirements openly, and some have different requirements for urban and rural areas.

With the help of our users and from published information, we have been able to come up with the following list of dates for light duty vehicles:

  • Argentina – 2009
  • Australia – 2006 (gas), 2007 (diesel)
  • Bolivia – 2016? (imports)
  • Brazil – 2007 (gas)
  • Canada – 1998
  • China – 2008 to 2012
  • Chile – 2013 (diesel), 2014 (gas)
  • Colombia – none
  • European Union – 2001 (gas), 2004 (diesel)
  • Hong Kong – 2006 (gas), 2009 (diesel)
  • Indonesia – 2016?
  • Iran – 2012
  • Israel – 2003
  • India – 2010 (some), 2013 (more)
  • Japan – 2002 (basic), 2008 (domestic), 2010 (imports)
  • Malaysia – 2015?
  • Mexico – 2006 to 2013
  • Morocco – 2011
  • New Zealand – 2006
  • Peru – 2016?
  • Russia – 2010
  • Singapore – 2014
  • South Korea – 2005 to 2010
  • Taiwan – 2006 (diesel), 2008 (gas)
  • Thailand – 2013
  • Turkey – 2013
  • USA – 1996
  • Venezuela – none
  • Vietnam – 2017?

Cars and light duty trucks that were manufactured for sale in the listed country after the date shown will likely work well with our products. If your vehicle is older than this, or was imported, it may not be OBDII compliant so may not work with our integrated circuits (even if it uses a similar looking connector). Note that large trucks and busses generally have different OBD requirements, and typically use different protocols too (usually SAE J1708 or SAE J1939).

Vehicles that comply with the OBDII standards will have a data connector within about one meter of the driver’s position. If the location is not obvious, check the owner’s manual as many newer vehicles list the location there. In most cases, it will be at the bottom of the dashboard, just out of sight from the driver’s position. Occasionally it will have a cover that needs to be removed, or moved sideways (there are a few vehicles that have the connector behind a panel in the centre of the dashboard).

The OBD connector is officially called an SAE J1962 Diagnostic Connector, but is also known by DLC, OBD Port, or OBD connector. It has positions for 16 pins, and looks like this:

J1962

Many older vehicles use a similar type of connector for communication with modules, but do not comply with the OBDII standards. Simply having a J1962 connector does not mean that the vehicle is OBDII compliant. Be aware of this when attempting to read vehicle codes (and be aware that you may cause damage to some circuits if you connect the wrong voltages to them). Always look first for a section on OBDII compliance in the owners manual, for a sticker in the engine compartment, or for information on the manufacturer’s web site, to be sure that you are dealing with an OBDII compliant vehicle.

Locate the J1962 connector in your vehicle, and determine if there are pins at positions 2, 6, 7, 10, 14 or 15. Once you know which pins are used and which are not, then determine which standard applies from the following table:

Pin 2 Pin 6 Pin 7 Pin 10 Pin 14 Pin 15 Protocol Use
must
have
must
have
J1850
PWM
ELM320
or
ELM327
must
have
J1850
VPW
ELM322
or
ELM327
must
have
may
have*
ISO
9141-2
or
14230-4
ELM323
or
ELM327
must
have
must
have
ISO
15765-4
(CAN)
ELM327
or
ELM329

* not all ISO9141 or ISO14230 vehicles use pin 15 (the ‘L’ line)

The above should be considered a good guideline. The presence or absence of pins in the connector is not an absolute indication though, as only your vehicle manufacturer can say for sure which standards the vehicle was built to.

Pre-2008 Typical Protocols

All new cars (2008+) seem to be going to the faster ISO 15765 (CAN) protocol, but older vehicles might have used one of several different protocols. The vehicle manufacturers generally stayed with one protocol, but not always (for example, Chrysler started using ISO 9141-2 and then switched to SAE J1850 VPW around MY2000). Typically, you will find the following standards usage for older vehicles:

Manufacturer J1850
PWM
(ELM320)
J1850
VPW
(ELM322)
ISO9141
ISO14230
(ELM323)
ISO15765
CAN
(ELM327 or
ELM329)
Acura X
Chrysler X X
Ford X
General Motors X
Honda X
Saturn X
Subaru X
Suzuki X
Toyota X
Volkswagen X

Actually, beginning with the 2005 model year, some North American vehicles did begin using the ISO 15765-4 (CAN) interface standard, so maybe we should have put some ‘X’s in the last column. The above should be a good starting point for you, though.

Beginning with the 2008 model year, all North American vehicles were required to use ISO 15765-4 (CAN).