Because my car is the mechanical-equivalent of a teenager, I have to start the biannual emissions check before renewing my license plate tabs. I knew Subarus had a blanket waiver from the dynamometer test because it effs with the all wheel drive, but I expected an exhaust probe while it idled. Instead, the test consisted of the following:
The OBDII is required on all cars manufactured after January 1, 1996. It’s supposed to be within three feet of the driver — for example, mine was just left of the underside of the steering column. There are three standards for pin layout and data transfer protocol: GM, Ford and everybody else.
If you’ve ever brought your car in for service because the “check engine” light popped on, the mechanic will ask you “are you sure you put your gas cap on tight?” Upon assent, they’ll plug in a similar computer, query the car, and examine the return codes. A very basic code reader (and MIL-resetter) can be had for $40. If you’re an enthusiast — or Ted — you’ll want the more sophisticated ODB-erator 2000. There are standard diagnostic trouble codes for the powertrain and the controller’s network. Eventually there will be additional standards for the body and chassis. Imagine, your car can rat you out for taking speed bumps at greater than the posted 15mph!