Yes, vehicles have computers and plenty of them. Since the late eighties computers have taken on greater roles every year in our vehicles to a point now where they have become vital. While to many of us computers and internet access are part of our daily work, we can still live and work without them until they’re back online. If a vehicle’s computer, commonly referred to as an ECM (Electronic Control Module) or BCM (Body Control Module), is down or doesn’t function correctly, the vehicle may run poorly, may not pass an emissions test, the windows and locks may malfunction or worse, it may not start and run at all. That’s because these days all major functions of an automobile are controlled, and monitored, by computers on their own networks. If something goes wrong with the vehicle, the computer will know and possibly record a fault code long before the MIL (Malfunction Indicator Lamp) comes on. Some issues are simple and can be taken care of next time you visit D & R Intensive Car Care and Lube Center for a service. Others are not and, if unchecked, can damage or destroy the vehicle’s engine. Unlike your home computer, your vehicle’s computer’s data cannot be seen on just any monitor. However, there is a way to retrieve your vehicle’s stored computer data, with automotive diagnostic equipment at D & R Intensive Car Care and Lube Center.
When computers began appearing in cars, the auto industry realized that standardization was needed. In the 1980s the Society of Automotive Engineers (SAE) came up with OBD, On Board Diagnostics, diagnostics data variables with a relatively standard connector plug. OBD’s mission was to reduce emissions, make sure failures could be discovered and fixed quickly via good diagnostics. Those standards were adopted by the very stringent CARB (California Air Resources Board) in 1985 and applied in 1988. They primarily checked the proper functioning of a few components and circuits related to emissions. Unfortunately, the original OBD standard was unable to identify a potential problem until it actually happened or a component completely failed, and by then it was too late. Learning from OBD, the first standard, OBD-II is an expanded set with much more standardization both in connectors and fault codes. OBD-II was adopted by CARB in 1989 and later by the EPA (Environmental Protection Agency). Starting in 1996, every vehicle sold in the US is required to have a computer that can generate the OBD-II codes and a standard OBD-II connector. Now OBD-II is a worldwide standard. Internationally, OBD is handled by the ISO (International Organization for Standardization). As a result, every car can accommodate the same DLC (Data Link Connector) and generates the same generic DTC (Diagnostic Trouble Codes).
To make things a bit more complicated, Diagnostic Trouble Codes can either be “generic,” common codes used by all manufacturers, or “enhanced,” codes used only by specific manufacturers. General Motors, Ford, and Chrysler all have their own set of enhanced codes. A standard OBD-II scan tool can read all those codes, but not necessarily interpret them as they may apply to a single vehicle of a particular model year.
There are also different Data Communication Network Interfaces (DCNI) for vehicles. In the US, SAE specifies “Class 2” J1850 VPW Variable Pulse Width (GM) and “SCP” J1850 PWM Pulse Width Modulation (Ford). Internationally, the ISO specifies the “K-line” 9141-2 standard (also used by Chrysler) and on newer vehicles the “KWP2000” 14230-4 standard. The Canadians use yet another standard. Not all of these protocols use the same pins on the connector, and sometimes, by a trained technician, it is possible to determine the protocols just by looking at what pins are present.
The car’s Data Link Connector, also called a female SAEJ1962 is generally located under the dash on the driver side, a foot or so away from the center of the dash. A diagnostic scan tool plugs into the DLC to read the codes generated and either displays them on its own LCD or passes them on to a more sophisticated computer.
The task of a scan tool is to interface with one or more of those automotive data communication network interfaces and read the codes stored in the current fault database and in the fault history database, assist in interpreting the codes meaning and clearing them from the database in order to turn of the MIL. A popular scan tool among automotive shops is the Snap-On® Solus™ Scanner™. A bit more sophisticated scan tool and lab scope combination is the Snap-On® Modis™, which is what we at D & R Intensive Car Care and Lube Center use for retrieving diagnostic trouble codes and checking your vehicle’s ignition system. With the Modis™ we are capable of not only reading diagnostic trouble codes and checking your ignition system but we can also trigger certain functions on your vehicle by turning them on and off. The Modis™ can operate your electric windows, electronic door locks, windshield wipers and washer pump, headlights, flashers, idle your vehicle up or down and even shift the gears in your vehicles automatic transmission just to name a few. These functions help D & R Intensive Car Care and Lube Center troubleshoot automotive diagnostic problems related to your vehicle’s ECM or BCM.
With computers, so much a part of today’s vehicles, the mechanics of years ago are now highly trained and certified technicians. Come see the highly trained and certified technicians at D & R Intensive Car Care and Lube Center today, and let us help you with your vehicle’s diagnostic needs.