Fastest way to find out, is to check here.

Two factors will show if your vehicle is definitely OBD-II equipped:

1. There will be a 16-pin OBD-II connector as shown below, and...
   
2. There will be a note on a sticker or nameplate under the hood: "OBD II compliant".

The Connector

Pin 2 - J1850 Bus+
Pin 4 - Chassis Ground
Pin 5 - Signal Ground
Pin 6 - CAN High (J-2284)
Pin 7 - ISO 9141-2 K Line
Pin 10 - J1850 Bus
Pin 14 - CAN Low (J-2284)
Pin 15 - ISO 9141-2 L Line
Pin 16 - Battery Power

Where Is the Connector Located?

The connector must be located within three feet of the driver and must not require any tools to be revealed. Look under the dash and behind ashtrays.

What Communications Protocol does my vehicle use?

As a rule of thumb, GM cars and light trucks use SAE J1850 VPW (Variable Pulse Width Modulation).

Chrysler products and all European and most Asian imports use ISO 9141 or KWP2000 circuitry.

Fords use SAE J1850 PWM (Pulse Width Modulation) communication patterns.

All 2008 and newer model year vehicles use CAN.

There are some variations among captive imports such as the Cadillac Catera, a German Opel derivative, which uses the European ISO 9141 protocol.

On 1996 and later vehicles, you can tell which protocol is used by examining the OBD II connector:

• J1850 VPW -- The connector should have metallic contacts in pins 2, 4, 5, and 16, but not 10.
• ISO 9141-2/KWP2000 -- The connector should have metallic contacts in pins 4, 5, 7, 15, and 16.
• J1850 PWM -- The connector should have metallic contacts in pins 2, 4, 5, 10, and 16.
• CAN -- The connector should have metallic contacts in pins 4, 5, 6, 14 and 16.

If your vehicle has this style connector, but doesn't have these pins populated, you probably have a pre-OBDII vehicle.

In summary: ELM327 interface supports all above protocols. Meaning it'll allow you to communicate with your car with software like TOAD.