Thursday, December 4, 2008

How to know

Lurking under the dashboards of our cars and trucks is a mysterious, multi-pin plug -- it's the industry-standard OBD-II (on-board diagnostics) port.

Unless we're among the savvy few who drive around with laptops docked to our vehicles, we have no use for OBD -- until the "check engine" light comes on, and then our mechanic plugs in, downloads data, and gives us the (often bad) news.

I don't like being dumb about what's going on inside my cars' black boxes, and I especially hate having to pay $60 for an hour of high-tech troubleshooting. A few years ago, a friend recommended I try something called a
CarChip.

The CarChip (MSRP $120, street $80), made by California-based Davis Instruments, is a small digital recorder (about the size of a pack of gum) that plugs into a vehicle's OBD-II port and captures up to 300 hours of data. After driving a little or a lot, the user unplugs the CarChip, connects it to a PC via a USB cable and downloads the recorded data -- a simplified version of what the dealer's mechanic does -- which can be displayed as tables or graphs.

The user gets to choose up to four of 23 possible OBD parameters for the CarChip to monitor and record. (Vehicle speed is always monitored.) In addition, the CarChip logs "trouble codes," as well as sudden stops and starts. Most parameters have thresholds that can be set according to personal preferences and vehicle specs.


I'm not exaggerating when I say that the CarChip represents the best eighty bucks I've ever spent on my vehicles. Often I've spotted trouble before it causes serious problems. Twice I've been able to learn the reason for the appearance of the "check engine" light and have taken care of it myself. And when I've had to delegate work to a qualified mechanic, it's been nice to have certain knowledge of what my vehicle's been doing.

As I said in yesterday's post, I've been pleased with the performance of the Chevy Trailblazer I bought used in October -- and thanks to the CarChip, that's more than just a seat-of-the-pants impression. I've asked the little gizmo to keep tabs on coolant temperature, battery voltage, fuel pressure and such, and so far, all is well.

(It's also easy, by the way, to surreptitiously slip the CarChip into a 16-year-old spawn's car and bust him for doing 90mph in the 25mph zone up the road. Trust me on that.)

Yes, there are other, similar gadgets on the market, but the CarChip works for me. You may consider that a recommendation.