OBD-II Information

Vehicles sold in the United States in 1996 and up are required by law to be fitted with an OBD-II system. At first there were a variety of ‘protocols’, or languages, used to transmit the information. In 2008, an standardized CAN bus communication method was required in all US vehicles. This newer communication is much after and faster than pre-2008 communication. Many vehicles between 2005 and 2008 upgraded early however, so you can often check your OBD-II connector to verify.

Please check your OBD-II connector prior to ordering to ensure that your OBD-II system is compatible with OneGauge. OneGauge currently offers two different products: one for pre-CAN bus systems (most vehicles made before around 2006 to 2008) and a faster option for CAN bus enabled vehicles (all 2008+ vehicles)!

The image below shows the standard OBD-II pinout. You can look at your OBD-II connector in your vehicle and match it up to this- if a pin is 'populated', or you can see a metal prong inside the space for that pin, then that communication style is available. For best results, we recommend ensuring your have the CAN high (pin 6) and CAN low (pin 14) pins populated. We do have an adapter available for other communication styles.  The list linked here also shows vehicles that were commonly available, before 2008, with Can Bus OBD-II communication - however, we strongly recommend checking the OBD-II connector to make sure. 

Please note that what we're really looking for is whether your vehicle supports ISO 15765-4. You may have pins 6 and 14 populated but have a fringe-case vehicle that doesn't support that CAN bus standard. It is your responsibility if you have a vehicle before 2008 to ensure that this specific ISO standard is implemented. If you're after 2008, you should be good because it was mandated in the United States.

Note that pre-2008 vehicles or engines without CAN-BUS will have slower communication (about 2-3x per second), so fast updating gauges like RPM will be slow to respond and the user will have noticeable lag. CAN-BUS enabled OBD-II ports (legally mandated since 2008) can communicate many times faster (50-100x per second, at least) so lag is not an issue.

What sensor readings can I get from OBD-II? 

There is a long list of sensor data that is transmitted by OBD-II, but this varies by year, make, model, and engine. RPM, Coolant Temp, MAP (boost/vacuum), IAT, fuel trim (short and long term), TPS, and MAF are standard, but most vehicles transmit much more information. We can only guarantee that the readings in the previous list are transmitted to OneGauge; since other sensors often require manufacturer- or engine-specific codes (called PIDs) to be able to read the data, it can be difficult to access these readings (examples include Oil Pressure and Fuel Level). Other companies and apps that develop gauges typically pay expensive licensing fees to the major auto manufacturers for the rights to these codes, though they can occasionally be found on the internet. We have had some success in getting GM and Ford specific PIDs to work, but these are not guaranteed since they can vary by year/engine/make/model.

For example, on modern GM platforms we can often add oil pressure, transmission temperature, and current gear! These are not guaranteed but often work with a little trial-and-error.

Installation notes:

OBD-II installation is nearly plug and play! Simply wire the OneGauge Hub for power using the 12v power inputs and plug your OBD-II cable or reader into the OBD-II port in your vehicle, which is usually located near the drivers’ left knee in left hand drive vehicle configurations. If you have any issues with your OBD-II setup please reach out to us at Info@TheOneGauge.com.

Remember! Just because you want a readout that the OBD-II connection doesn't support doesn't mean you have to go without it! Simply wire in one of our standalone sensors for simple, easy, fast data!