The onboard electrical diagnostic system in your car is called the OBD-II. This system of codes assists the scanner in checking your automobile’s systems and their performance. All cars built after 1996 have an OBD-II on board. Some older models had diagnostics installed as after-market products. These systems are not always recognizable, but may be found if you know what to look for.
Look in unlikely places such as in the cover above the floor or under the ashtray in older model cars for a connection that looks like a mouth with two rows of teeth, with 16 possible points of connection. Some systems were placed under the dashboard. The connection must be placed within three feet of the driver.
Watch for a light to flash on your dashboard that says, “check engine.” This light is usually indicates the presence of an OBD-II scanner.
Ask your mechanic to perform a scan of your electrical systems. If he attaches wires to a computer and receives data on it, then you most likely have an ODB-II scanner. You could just ask your mechanic too.
Rifling around under the hood will most likely give you very little information, since the OBD-II is in a sealed casing. Look instead for a sticker placed under the hood that states the car is OBD-II compliant.
Check with the California Air Resources Board for a list of vehicles that were OBD-II compliant prior to 1996. See “Resources” for more information.