About compatibility and OBD-II standard

Is Car Scanner compatible with my car? I receive lot’s of e-mails with this question and it’s not as easy as it seems.

Car Scanner is compatible with all cars, that are compatible with international standards SAE J1979 and ISO 15031-5, that are both known as OBD-II standard.

What is OBDII standard?

If in fact is a set of rules and requirements that must be met for a car in order to be able to diagnose faults associated with the possible harm to the environment. Yes, the OBDII standard is primarily designed to prevent harm to the environment, but it actually helps to diagnose other faults.

The OBDII standard includes requirements to the hardware and software of the car.

For us it is important that the hardware requirements is the mandatory presence of the standard D-shaped diagnostic connector with 16 pins. To this connector we plug in the ELM327 adapter.

Requirements for software include mandatory support for the car one of the protocols:

  • SAE J1850 VPM
  • SAE J1850 PWM
  • ISO 9141-2 / ISO 14230-4 KWP
  • ISO 15765-4 CAN
  • SAE J1939 CAN

In addition, the standard regulates the list of possible queries and deciphering their answers. For example, to find out the current engine speed, it is necessary to perform a “010C” request. Each bit in the response equals 0.25 rpm.

What cars support OBDII standard?

A common misconception is that this standard supports all vehicles from 1996 model year. No, it is not. During the development of a Car Scanner I’ve tested a lot of cars. Even more vehicles had been tested by thousands of users who have written to me.  So I have collected some information about OBDII standard support.

The OBDII standard was introduced as mandatory in USA for all cars made since 1996 for the US market.

What about European Union? OBDII standard (or European OBD – EOBD) was introduced as mandatory for all gasoline (petrol) cars only since 2001. Since 2003, it became mandatory for all diesel vehicles sold in the EU.

In 2008, the standard became mandatory for all vehicles produced for the Chinese market.

In 2005-2006 it became mandatory for Australia.

Please note – we are not talking about cars made in the USA, EU, China or Australia. We are talking about cars produced for USA, EU, China.

But what about the Japanese auto industry? In Japan this standard is not mandatory. So RHD cars produced for the Japanese market in the majority do not support the OBDII standard. If the Japanese make a car for the US/EU/Chinese market, they add support of OBDII standard.

And what about the rest of the world? I have no information for all countries, but in most of other countries OBDII support is not mandatory. When it’s not mandatory in your country – OBDII support is just the good will of your car manufacturer. Or not…

For this reason, some cars produced for the European market before 2001 support OBDII standard – car manufacturer has decided add it for all markets.

But there are lot’s of opposite cases – when car manufacturer included OBDII D-shaped connector from the American version in European modification, but installed another electronic control unit (ECU) or firmware without OBDII support. The connector is there, but the software part doesn’t support OBDII standard.

It is important to distinguish OBDII diagnostics and diagnostics using vehicle manufacturer’s proprietary protocols.

Diagnosis based on the OBDII standard is universal. The ELM327 chip doesn’t care what vehicle it is connected. Communication protocols, parameters and sensors are regulated by the standard. The list of supported parameters reported by the car itself.

But in addition to the OBDII diagnostics most cars support advanced diagnostics in “manufacturer” mode.

In most cases, ELM327 can’t be used to operate in “manufacturer” mode. Although many car makers have embed advanced diagnostic functionality to OBDII protocol, and, theoretically, you can use ELM327 adapter to access these functions (like Toyota, Ford, etc.).

The main problem, in this case, you do not know where those functions are located and what exactly they tell you or do. You don’t want to accidentally turn off the third injector, I suppose? All dealer’s documents, related to advanced diagnostics are closed. Access to documentation for these protocols costs from $ 10,000 to $ 100,000 depending on the vehicle manufacturer.