DMV recommends consumers do not wait until the last minute to get an inspection. Customers can take vehicles in for inspection up to two months before the inspection is due. Customers need to work with their mechanic/dealer to get vehicle repaired as soon as possible. Always carry the Vehicle Inspection Report (VIR) in the vehicle, showing that you are working towards compliance.
The vehicle should be driven under a variety of normal operating conditions in order for the OBD system to become ready. These operating conditions include a mix of highway driving and stop and go, city type driving, and at least one overnight-off period. Your vehicle owner’s manual should provide more specific information on getting your vehicle’s OBD system ready. For more information on readiness, please visit: http://dec.vermont.gov/ sites/dec/files/aqc/ mobile-sources/ documents/ Readiness.pdf
If your vehicle’s OBD system is not ready, the inspection of the OBD system cannot be completed. While this does not necessarily mean that your vehicle has a problem, it does indicate that your vehicle’s OBD system has not yet completed it’s tests, and problems may be present, but not yet identified. A recently disconnected or discharged (run down) battery, or recent servicing using a scan tool are the most likely reasons for a vehicle’s OBD system being “not ready.” Note that there are a few vehicles which should not be rejected as “not ready”. Ask your inspection station or the Department of Motor Vehicles for further information about these exceptions.
First, the vehicle is checked to see if the Malfunction Indicator Light (commonly called the “check engine” or “service engine soon” light) on the instrument panel illuminates when the ignition key is turned to the “on” position and then when the engine is running. Next, an electronic device known as a scan tool is connected to the vehicle, and used to communicate with the vehicle’s on board computer. The on board computer is checked to confirm that the vehicle has completed self-tests, to determine if the computer has attempted to turn on the Malfunction Indicator Light, and if applicable, to retrieve diagnostic trouble codes. The results are recorded, and the scan tool is disconnected from the vehicle. The entire OBD check typically takes less than 5 minutes.
Motor vehicles are the largest source of toxic and ozone-forming air pollutants in Vermont. While modern vehicles are getting much cleaner due to newer engine management technology and emission control components, emissions stay low only when all these systems are working properly. OBD technology helps to ensure that vehicles are operating as designed, and the OBD check ensures that the vehicle’s OBD system is doing its job.
OBD technology was developed in the 1980s by vehicle manufacturers to help technicians diagnose and service the computerized engine management systems of modern vehicles. A new generation of OBD (often referred to as OBD II) is present on 1996 and newer vehicles. OBD II monitors all components of the engine management system and can detect a malfunction or deterioration of these components usually well before the driver becomes aware of any problem. When a problem is detected, the OBD system turns on a warning light on the instrument panel to alert the driver of the need to have the vehicle checked by a service technician.
A scan tool with generic OBD II capability is necessary to perform the required check. A scan tool is a very useful device which is commonly used to assist in the diagnosis and repair of a variety of vehicle problems. Many inspection stations already own scan tools which can also be used to perform the required OBD check, but those inspection stations which do not will need to have one in order to inspect 1996 and newer vehicles. At a minimum, scan tools must be capable of :
Any scan tool which complies with Society of Automotive Engineers Recommended Practice J1978 is acceptable. Scan tools are available from a number of well known equipment manufacturers.
Please visit http://dmv.vermont.gov/AVIP for details.