Scan tools can provide vital data from vehicle
Q I have three different vehicles that I try to maintain, along with trying to pass vehicle system enigmas along to my sons and their assorted vehicles. What would be a “quality” OBD-II scan tool for use, in a variety of cars and trucks, now and into the near future?
— Sam Bass
A This is a fun topic, as these tools keep getting better and better, regardless of brand. A scan tool allows one to communicate with a vehicle's engine management and other computers. Scan tools come in basically four formats: OBD-II compliant, which are inexpensive and home-tech friendly; PC- and smartphone-compatible modules; professional-grade aftermarket; and manufacturer-specified, which can cost as much as $10,000.
U.S. vehicles built since 1996 are required to communicate via a standardized protocol, at least for emission-related topics. OBD-II, or On-Board Diagnostics 2, generic scan tools are widely available for $40 to $200 and allow a number of functions:
• Checking and clearing pending or current emission-related diagnostic trouble codes, observe emission test readiness;
• Replaying freeze-frame data (a snapshot of engine data taken by the vehicle when an emission fault occurs);
• Observe live engine data, which includes only about 15 to 20 items on most 1996 to 2004 vehicles and many more since;
• Check calibration status;
• A few other general functions.
Mid-priced OBD-II scan tools do all the above, and likely display trouble code descriptions and manufacturer-specific trouble codes, which begin with P1 and P3. That goes beyond the standardized codes mandated by OBD-II, which begin with P0 and P2. Higher data-refresh rates and more sophisticated display screens often provide the ability to graph data, besides displaying it in list form, which can be helpful to spot a glitch or irregularity. Connecting and printing to a PC might also be possible.
Scan tools approaching the upper end of the price range can look at more detailed information; record and play back data; display bilingual or trilingual information; allow online updating and website access; and hold information for off-car playback. As prices hit the $200-and-up range, coverage for antilock brake system and supplemental restraint system can be found, as well as coverage for certain, generally domestic pre-1996 OBD-1 vehicles.
It's important to remember that OBD-II generic information is a limited but useful slice of the whole engine and vehicle pie. It's great to be able to identify the general cause of an illuminated check engine light, but additional diagnostic information and testing often are needed to nail down the problem. For the price, these tools are magnificent.
If considering a pre-owned or lower-end scan tool, be sure it's compatible with CAN, a newer communication protocol, and does most of the things mentioned in my description of generic scan tools. Don't come home with just a code reader.
Brad Bergholdt is an automotive technology instructor at Evergreen Valley College in San Jose, Calif. Readers may send him email at email@example.com; he cannot make personal replies.
Show commenting policy
TribLive commenting policy
You are solely responsible for your comments and by using TribLive.com you agree to our Terms of Service.
We moderate comments. Our goal is to provide substantive commentary for a general readership. By screening submissions, we provide a space where readers can share intelligent and informed commentary that enhances the quality of our news and information.
While most comments will be posted if they are on-topic and not abusive, moderating decisions are subjective. We will make them as carefully and consistently as we can. Because of the volume of reader comments, we cannot review individual moderation decisions with readers.
We value thoughtful comments representing a range of views that make their point quickly and politely. We make an effort to protect discussions from repeated comments either by the same reader or different readers.
We follow the same standards for taste as the daily newspaper. A few things we won't tolerate: personal attacks, obscenity, vulgarity, profanity (including expletives and letters followed by dashes), commercial promotion, impersonations, incoherence, proselytizing and SHOUTING. Don't include URLs to Web sites.
We do not edit comments. They are either approved or deleted. We reserve the right to edit a comment that is quoted or excerpted in an article. In this case, we may fix spelling and punctuation.
We welcome strong opinions and criticism of our work, but we don't want comments to become bogged down with discussions of our policies and we will moderate accordingly.
We appreciate it when readers and people quoted in articles or blog posts point out errors of fact or emphasis and will investigate all assertions. But these suggestions should be sent via e-mail. To avoid distracting other readers, we won't publish comments that suggest a correction. Instead, corrections will be made in a blog post or in an article.
- Indian SUV maker Mahindra to debut electric scooter in U.S.
- NexTier Bank buys Oakland’s Eureka to increase coverage in Western Pennsylvania
- Robust jobs report could force Federal Reserve to raise interest rates
- Alcoa putting $60M into Upper Burrell tech center expansion
- Stocks end roller-coaster day higher
- Fifth Third Bank selling Pittsburgh branches to First National
- Stock indexes enter correction territory; bear market could be lurking
- Housing bright spot as Beige Book survey shows Pittsburgh region’s growth slight
- Coal stocks on a roller coaster ride they can’t get off
- Fund fees within investor control
- Just Mayo has egg industry in a panic, emails show