The OBD2 port sits in the driver’s footwell. Here is what the rule says and how to find yours.
Before an adapter can read anything, it has to reach the diagnostic connector. California’s rule fixes where that connector may sit in a car. This guide turns the rule into a short, safe search.
The plain answer
On a modern car the OBD2 connector is low on the driver’s side of the cabin, under the dashboard near the steering column. A scan tool or an ELM327 adapter plugs straight into it. You do not need to remove trim to find it on a recent vehicle, and you should not pry anything apart to look.
Look low and on the driver’s side. The rule says the connector may not sit in or on the center console.
That answer comes from a written rule, not from folklore. The sections below quote it, say what it does not cover, and give you a search order that works when the first glance fails.
What the California rule says
California’s on-board diagnostic regulation, 13 CCR §1968.2, section (g)(2), sets the diagnostic connector requirements for passenger cars, light trucks and medium-duty vehicles. The U.S. EPA requires model year 2017 and later vehicles to meet the July 2013 edition of California’s requirements. The table shows the current California edition and keeps its wording close to the original. An earlier edition may differ in detail.
| Question | What the rule says | Section |
|---|---|---|
| Which connector? | A standard data link connector conforming to the “Type A” specifications of SAE J1962. | (g)(2.1) |
| Where? | Within “the driver’s side foot-well region of the vehicle interior”, between the driver’s side of the vehicle and the driver’s side edge of the center console, or the vehicle centerline when there is no console. | (g)(2.1.1) |
| How high? | No higher than the bottom of the steering wheel when it is in its lowest adjustable position. | (g)(2.1.1) |
| Console? | “The connector may not be located on or in the center console.” | (g)(2.1.1) |
| Cover? | If covered, the cover must be removable by hand without tools and labeled. Access may not require opening a storage accessory such as an ashtray. | (g)(2.1.2) |
| Newer vehicles? | For 30 percent of 2019, 60 percent of 2020 and 100 percent of 2021 and later model-year vehicles, the connector may not be covered in any way. These phase-in vehicles follow the location in SAE J1962 (September 2015 version). The rows above cover vehicles outside the phase-in. | (g)(2.2.2) |
The rule also says the location must be easy for a crouched technician to identify when entering from the driver’s side. It bars a second connector in the same area that can accept J1962 Type A test equipment, so a second look-alike socket there is not a sign of a spare.
What the rule does not promise
- Older vehicles. The text above is the current California edition. A car built years earlier followed an earlier edition and may place the connector differently or cover it with a panel.
- Other countries. The European Union requires on-board diagnostics to offer “unrestricted and standardised access”. The wording about where the connector sits is not the California text, so do not assume the same spot without a check.
- Heavy-duty trucks. California’s heavy-duty rule allows a connector conforming to SAE J1962 or SAE J1939-13. A truck built to the second option may have a different connector, and a passenger-car adapter may not fit it.
- Condition. The rule says where a connector belongs. It does not say the wiring behind it is intact, powered, or compatible with your adapter.
A safe way to find it
- Park the car, set the parking brake, and turn the engine off.
- Sit in the driver’s seat and look low, left of the steering column and just below the dash edge. Use a phone flashlight rather than reaching blind.
- Look for a small label or a flap. If a cover is fitted, it should lift off by hand. Do not use a tool, and stop if it will not move.
- Scan the whole strip under the dash. The rule allows any spot between the driver’s side of the car and the edge of the center console (or the centerline when there is no console), so look beyond the steering column.
- If you still see nothing, open the owner’s manual and search the index for “data link connector” or “diagnostic connector”.
- When you plug in, push the adapter in straight, then keep the cable clear of the pedals and the steering column before you start any scan.
Stay parked while you set up. Reading or clearing anything while driving is a safety problem for you and for other road users.
If you cannot find it
Check the manual first, then ask a qualified shop to point it out. A car built before OBD II became mandatory (1996 in the United States) may lack the standardized connector, and a car imported from another market may follow that market’s rules. Our compatibility guide lists the model-year starting points we could verify in the regulations.
What the port is, and what it is not
The connector gives standardized electrical access to the vehicle’s emissions diagnostics. It is a doorway. What comes through depends on the vehicle, the adapter, the phone, and the protocol in use. For the protocol side, see OBD2 protocols explained.
Axlyne’s boundary
Axlyne records supported standard generic OBD2 responses through a separate compatible ELM327 adapter that you plug into this connector. Support varies by vehicle, adapter and phone. Axlyne does not identify a failed part, certify safety, or replace a qualified inspection. Set it up while the vehicle is parked.
Official sources
- California Code of Regulations, Title 13, §1968.2, section (g)(2) Diagnostic Connector
- California Air Resources Board, On-Board Diagnostic II systems fact sheet
- U.S. EPA, 40 CFR 86.1806-17, onboard diagnostics for 2017 and later vehicles
- California Code of Regulations, Title 13, §1971.1, heavy-duty on-board diagnostics
- European Union, Directive 98/69/EC, recital on unrestricted and standardised access
- SAE International, J1962 diagnostic connector