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A CDE Definition

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(On-Board Diagnostics) A vehicle's electronic troubleshooting system. Dating back to the late 1960s when the first diagnostic computer was employed in a Volkswagen, the OBD system reports trouble codes (DTCs) by plugging in an ODB scanner that reads them.

Initially only used by auto mechanics, today, anyone can plug in a scanner to find out why the Check Engine light is on. Units may only display codes, while others report more information, and some can even predict failure.

Starting in the late 1960s, there were various diagnostic interfaces from Volkswagen, Datsun and General Motors, but in 1991, California required a basic set, loosely referred to as OBD I. However, it was not until 1996 that OBD was standardized for all U.S. vehicles with the OBD II specification.

OBD III has been proposed to report emission failures to a regulatory agency, which requires the owner to have the vehicle serviced before the inspection due date. Very controversial, OBD III is seen as excessive invasion of privacy.

OBD II Connector Type A (12 Volts)
Standardized as the SAE J1962 interface in 1996 for the U.S., a scanner is plugged in to read the codes. This 16-pin socket is accessible under the dashboard.

Do It Yourself
Car owners can diagnose their vehicles with this handheld scanner. After retrieving the data from the OBD port, the unit is plugged into a PC for a report with suggestions and cost estimates. (Image courtesy of Corporation,

Maintenance, Tracking and Wi-Fi
Plugged into the OBD port, T-Mobile's SyncUp sends maintenance notifications in real-time to the user's smartphone. Also used for vehicle tracking, trip history and driving behavior, it can even generate Wi-Fi for passengers (see Wi-Fi hotspot).

Wi-Fi hotspot

The geographic boundary covered by a Wi-Fi (802.11) wireless access point. Typically set up for Internet access, anyone entering the hotspot with a Wi-Fi-based laptop, smartphone or tablet can connect to the Internet, providing the access point is configured to advertise its presence (beaconing) and authorization is not necessary. If authorization is required, the user must know the password. In addition to Internet access, all shared folders on everyone's computer currently in the hotspot are also accessible.

Create Your Own Hotspot
Wi-Fi hotspots can also be created by users from their smartphones, tablets or third-party device that plugs into the vehicle's maintenance port. See cellular hotspot and OBD.

The Wi-Fi Network May Be Hidden
An access point is invisible if it is not advertising its presence (not beaconing). To gain access, a user must know the network name (see SSID) and most likely the password as well.

Public Hotspots
According to JiWire, Inc., at the beginning of 2010, there were more than a quarter million public hotspots around the world. However, every home or business Wi-Fi network is a hotspot, and if the wireless router is left in its default state, which advertises its presence and does not require a password, it too is inadvertently a public hotspot.

Following are some of the websites that report the whereabouts of public hotspots. Contrast with notspot. See Wi-Fi, Wi-Fi Passpoint, cellular hotspot, hotspot finder, access point, war driving and Muni Wi-Fi.

Hotspots Are Everywhere
Even local supermarkets offer Wi-Fi to encourage customers to linger in their cafes.

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Before/After Your Search Term
OAM multiplexingOBJ file
OATHobject-based audio
OAuthobject-based music
OAWobject-based surround sound

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