About car compatibility and OBDII 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 ELM327.

And ELM327 is compatible with OBDII compliant cars.

What is OBDII?

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, and then 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 diagnostic connector in the form of a trapezoid with 16 contacts. 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.

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 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.

Please note – we are not talking about cars made in the USA, EU, China. 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/Chinees market, they add support of OBDII standard.

And what about the rest of the country? 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 the car manufacturer.

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 inculuded OBDII 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.

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 “dealer” mode.

In most cases, ELM327 can’t be used to operate in “dealer” 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 excatly 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.

 

Some people are working on decipher dealer protocols. As a result, Car Scanner supports Nissan Consult II and has sets of additional sensors for different cars. You can read more in other articles, like Connection to the Nissan/Infinity/Datsun.

Summary

Most of the cars produced for the European and US markets after 2003 support OBDII standard.

Cars that doesn’t support the OBDII standard, even with the appropriate connector: