Related Information
For more details about OBDII, AAA has produced a brochure. For a free copy, send a self-addressed, stamped business-size envelope to: AAA, OBD inspections, 12901 N. Forty Drive, St. Louis, MO 63141. You also can pick one up at your nearest AAA office or AAR facility.

Clearing the smoke on emissions inspections
Model year 1996 and newer vehicles in metropolitan St. Louis must have their emissions checked using a new test
Published: Jan/Feb 2003
By Dennis R. Heinze
Regional Editor

The “Check Engine” light is turned on anytime your vehicle finds a fault that could cause increased exhaust emissions.
Like a smoke detector for your house, the On-Board Diagnostic system in your car (OBDII) is an early warning system that detects when your car is having emissions problems, and now there's a new test for 1996 and newer vehicles in metropolitan St. Louis to make sure the system is working properly.

The OBDII computer system, which is installed on all 1996 and newer cars and light trucks, monitors your vehicle's emissions control devices and drive train components. The system can identify a problem before the driver recognizes symptoms, such as engine misfires, poor fuel economy, increased exhaust emissions, change in engine performance or idle quality.

When it identifies a problem, the system will illuminate a special amber lamp called a MIL (malfunction indicator lamp) that reads “Check Engine” or “Service Soon.” This lamp is reserved for emissions problems only; it is turned on anytime the OBDII system finds a fault that could cause increased exhaust emissions.

If the MIL comes on, you may not notice any real change in the engine's operation. However, your vehicle might have a condition that could waste fuel, shorten engine life or cause an increase in vehicle emissions. But there is no need to panic.

Continue to monitor the MIL while going about driving. If the light goes out after a few short trips, the problem was likely temporary in nature. If it remains on, you should have the vehicle diagnosed and serviced by a qualified repair technician.

However, if the MIL is blinking, a severe engine problem is occurring and should be checked as soon as possible. A blinking MIL means that a catalytic converter damage condition exists. Slow the vehicle down, minimize your travel and have the vehicle checked out immediately.

AAA offers a list of qualified repair facilities in the area that have technicians trained in OBDII system diagnostics and repair. Simply visit www.aaa.com and click on the automotive section to locate the Approved Auto Repair (AAR) facilities that meet AAA's rigid standards for quality. Or call AAA at 1-800-222-7623 ext. 6821.
Inspecting OBDII

Vehicles in the St. Louis metropolitan area that are model year 1996 and newer must have their OBDII system checked every two years. Included in the testing region are vehicles registered in St. Louis city and the Missouri counties of St. Louis, St. Charles, Jefferson and Franklin, as well as vehicles in selected zip codes in the Illinois counties of Madison and St. Clair.

Newly purchased vehicles in Missouri do not have to be tested until two years after the initial purchase (based on the model year, not the calendar year), and that period is four years in Illinois. However, if the vehicle is sold, that grace period is eliminated.

When your vehicle is tested, the technician connects a scanner to your vehicle's OBDII system. The inspector checks the operation of your vehicle's MIL lamp and the status of the OBDII system. If the MIL functions properly and there are no stored DTCs (diagnostic trouble codes) in the system, the emissions inspector then checks the status of the “readiness monitors.”

Readiness monitors are indicators used to find out if your vehicle's computer has evaluated the OBDII system. If all of the monitors are set to “ready,” the OBDII system has checked the integrity of the emissions systems.

The preferred location of the Diagnostic Link Connector (DLC), the component that the test equipment is connected to, is on the underside of the instrument panel below the steering column. Some vehicles have their DLCs in other locations.

For those affected vehicles older than model year 1996, usually a dynamometer test called the IM240 test is used. Your car is run on a vehicle treadmill, and the test measures exhaust emissions to determine if your vehicle is producing emissions that are above set standards.

Missouri inspections

For motorists in the Missouri portions of the area affected, if your 1996 or newer vehicle fails the OBDII test (until Jan. 1, 2005), it will be checked using the IM240 test. If your vehicle passes the IM240 test, it will receive a passing certificate.

If your vehicle fails both the OBDII test and the IM240 test, your vehicle will have to be repaired. After repairs, your vehicle will again be tested using the OBDII test first. If it passes this test, your vehicle will receive a passing certificate. If it fails the OBDII test, it will once again be tested using IM240. If it passes the IM240 test, the vehicle will receive a passing certificate. If it fails the IM240 test, and you have spent at least $450 on repairs and these repairs have resulted in a reduction of the failing pollutant, then your vehicle is eligible for a waiver.

Beginning January 2005, the St. Louis area will start using the OBDII test as a pass/fail test. If the vehicle passes the OBDII test, the vehicle will receive a passing certificate. If the vehicle fails the OBDII test, the vehicle must be repaired to pass the OBDII test and the vehicle is not eligible for a waiver.

In the Missouri portion of the St. Louis metropolitan area, the RapidScreen program allows motorists to pass the emissions test without visiting a test facility. Special equipment is used to check a vehicle's exhaust emissions while the vehicle is being driven. When you do drive past a RapidScreen test van, do not change your driving habits.

All vehicles are eligible for this option, even if your MIL light is on. Simply drive your vehicle past one of the mobile test sites (you can find the time and location of the RapidScreen vans at the Web site www.gatewaycleanair.com).

Two valid RapidScreen tests are needed to exempt a vehicle. These two tests must be recorded no more than 12 months before the vehicle's emissions test is due, and the test results must be recorded on two separate days. If the vehicle records more than two tests during the past 12 months, the two most recent tests are used to evaluate the vehicle. The last two tests must have resulted in a passing grade for the vehicle to earn an emissions certificate.

Owners of eligible vehicles will be notified up to 60 days prior to vehicle registration. If your vehicle is “clean,” you will not need to have the vehicle tested at one of the test facilities. If the MIL light is “on,” you should have your vehicle checked by a repair facility to determine the cause of the light.

Illinois inspections

In select zip codes of the Illinois counties of Madison and St. Clair (until January 2004), if your vehicle fails the OBDII test, the owner must decide what is to be done next.

One of motorist's choices is repair the vehicle to pass the OBDII test. Once the vehicle has been repaired, the vehicle is retested using the OBDII test.

Or the owner can choose to have his or her vehicle tested using the IM240 test. If the vehicle passes the IM240 test, the vehicle will receive a passing certificate, even though the vehicle failed the OBDII test. If the vehicle fails the IM240 test, the vehicle must be repaired to pass the IM240 test. If the vehicle cannot be repaired to pass, the owner must spend at least $450 on emission-related repairs and these repairs must result in a reduction of the failing pollutant before the owner is eligible for a waiver.

Beginning in January 2004, Illinois will begin using the OBDII test as a pass/fail test. If the vehicle passes the OBDII test, the vehicle will receive a passing certificate. If the vehicle fails the OBDII test, the vehicle must be repaired to pass the OBDII test. Unlike Missouri, a waiver system is being developed for those cars that do not pass after that time in Illinois.

Older vehicles more prone to fail

To assess OBDII vehicles, AAA tested more than 1,200 1996 and newer vehicles in 2001. The study found that older vehicles had a higher percentage of OBDII failure. Additionally, vehicles with greater mileage had a higher likelihood of a MIL illumination.

Most 1996 and newer vehicles will be tested using the OBDII test; however, there are some vehicles that have communication or readiness issues, AAA found. Readiness and communication issues are usually found on 1996 and 1997 model year vehicles, and they are found more often on import vehicles than domestic. In AAA's study, more than 22 percent of the model year 1996 vehicles failed the OBDII test and more than 16 percent of the 1997 vehicles failed. Comparatively, less than 9 percent of the 2001 vehicles and none of the 2002 vehicles failed.

If, during testing, your vehicle's computer does not communicate with the test station computer, the vehicle cannot be tested. Some vehicles have known communication problems. In the St. Louis metropolitan area, these vehicles will then be tested using the dynamometer test. If the vehicle passes the dynamometer test, the vehicle will be issued a passing certificate. Most communication problems have been found on older vehicles, the AAA survey found.

If you've had your car repaired and the MIL comes on, don't assume the repair facility didn't fix the vehicle properly. There are several hundred DTCs that can turn on the MIL, but there is only one light. The MIL may be on for a completely different problem than the previous time.

Make sure your repair facility lists the DTCs on the repair invoice for your future reference. If the MIL comes on later, let the technicians diagnose the vehicle and tell you the DTC that is stored this time. If the DTC is the same as the last repair, remind them that they had just repaired the vehicle for the same problem. If the DTC is different, your vehicle's OBDII system has detected a different condition than before.

To minimize exhaust emissions, AAA advises you to maintain your vehicle according to the manufacturer's recommended schedule. Keep up with routine maintenance (oil changes, air filter replacement, PCV valve operation checkups). Always turn off the engine before refueling, and make sure the gas cap is securely tightened when you are finished.

Federal law requires emissions components on 1995 and newer vehicles be covered by warranty for two years or 24,000 miles, whichever occurs first. Most manufacturers provide extended warranties beyond what is required by law. Federal law also requires that your vehicle's OBDII computer and catalytic converter be covered by an eight-year/80,000 mile warranty. Refer to your owner's manual for complete coverage information.

For more details about OBDII, AAA has produced a brochure. For a free copy, send a self-addressed, stamped business-size envelope to: AAA, OBD inspections, 12901 N. Forty Drive, St. Louis, MO 63141. You also can pick one up at your nearest AAA office or AAR facility.




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