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Vehicle emission testing

Which vehicles require an inspection | When inspections are required | Inspection stations | Procedure | About the Wisconsin Vehicle Inspection Program | Recent renewal notice changes

Which vehicles require an inspection

Wisconsin requires emissions inspections for cars and trucks that:

• are powered by gasoline or alternative fuels (but not diesel fuel); and
• are model year 1996 or newer; and
• have a manufacturer's gross vehicle weight rating (GVWR) under 8,501 pounds; and
• are customarily kept in one of the following seven southeastern Wisconsin counties:
  • Kenosha
  • Milwaukee
  • Ozaukee
  • Racine
  • Sheboygan
  • Washington
  • Waukesha

Effective January 1, 2010, the inspection requirements are expanding to include model year 2007 and newer vehicles that:

• are powered by diesel fuel; and/or
• have a GVWR between 8,501 pounds and 14,000 pounds

Motorcycles and dedicated farm vehicles are exempt from inspection, and will remain so after January 1.

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When inspections are required

Vehicles require inspection every other year at the time of license plate renewal, beginning in the third year following the vehicle's model year. (For instance, model year 2007 vehicles first require an inspection in 2010.) Renewal notices indicate if an inspection is required.

In addition, vehicles more than five model years old require inspection within 45 days following registration by a new owner. The Wisconsin Department of Transportation (WisDOT) mails a letter to the new owner outlining the inspection requirements.

Vehicles subject to emissions inspection may fulfill the inspection requirement up to 180 days prior to their license plate renewal date. You can determine whether your vehicle is due for inspection within the next 180 days by entering your license plate on WisDOT's plate inquiry page. If the inquiry result page includes the statement "IM test is needed," your vehicle's plate renewal date falls within the next 180 days. You do not need a renewal statement in order to receive your inspection; simply visit the station registration desk before entering an inspection lane.

When a vehicle does not pass an inspection by the license plate renewal date, its registration is suspended. In such cases, the owner must satisfy emissions inspection requirements to legally operate their vehicle.

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Inspection stations

Vehicles can be inspected at any of the nine vehicle inspection facilities located in Sheboygan and throughout southeastern Wisconsin. The Burlington, Cedarburg, and south Waukesha inspection facilities all have closed permanently effective October 1, 2009. 

Station hours are as follows:

• Monday: 8:30 a.m. - 5:30 p.m.
• Tuesday: 8:30 a.m. - 5:30 p.m.
• Wednesday: Closed.
• Thursday: 8:30 a.m. - 5:30 p.m.
• Friday: 8:30 a.m. - 5:30 p.m.
• Saturday: 8:00 a.m. - 1:00 p.m.
• Sunday: Closed.

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Procedure 

All vehicles subject to inspection are equipped with second-generation On Board Diagnostic (OBDII) computer systems, and are inspected by means of a computer system "health-check". This check consists of plugging a scan tool into the vehicle's computer and downloading emission control systems information. As of July 1, 2008, the program no longer conducts tailpipe testing or gas cap testing. 

With slight variations depending upon the circumstances, the inspection procedure is as follows: 

1. The motorist drives the vehicle into the inspection facility.
2. The motorist hands the inspector the license plate renewal notice (for renewal-based inspections) or a past vehicle inspection report (for re-inspections).
3. The inspector verifies the vehicle's identity and then enters data into a computer to record the vehicle's weight, model year, and mileage.
4. The motorist shuts off the engine and exits the vehicle.
5. The inspector enters the vehicle, and checks both the dashboard malfunction indicator lamp (MIL) and data link connector (DLC) located on the dashboard.
6. The inspector restarts the engine and connects an OBD scan tool to the data link connector, initiating a data download from the vehicle's OBDII system.
7. The inspector exits the vehicle, and enters MIL and DLC information into a computer.
8. Once the OBDII system data download is complete, the inspector removes the scan tool from the DLC.
9. The inspector retrieves the vehicle inspection report from a nearby printer and issues it to the motorist; Depending on the inspection outcome, the inspector may provide the motorist with additional materials and/or instruction. 

Once a vehicle passes its inspection, the motorist may renew the vehicle's registration at the inspection facility, by mail, the Internet, or in person at any of the WisDOT DMV service centers offering vehicle registration service. All inspection facilities have the ability to process renewals. The computer matches records from the inspection stations with WisDOT's registration records to verify that the inspection has taken place. 

If a vehicle fails its inspection, the owner must pursue appropriate repair(s) prior to submitting the vehicle for re-inspection. Satisfactory completion of the inspection requirement is necessary before the owner may receive a license plate registration renewal. The inspector gives all motorists an informational brochure at the time of the initial inspection to explain the repair and retest process. 

Call (414) 266-1080 or (800) 242-7510 for more information.

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About the Wisconsin Vehicle Inspection Program

Why vehicles are tested

The federal Clean Air Act mandates the operation of vehicle emission inspection and maintenance programs in areas throughout the nation with significant air quality issues, including Southeastern Wisconsin. In addition to identifying vehicles violating state emission standards, the Wisconsin Vehicle Inspection Program (WVIP) also identifies vehicles with tampered emission control equipment. The owners of these vehicles are required to have tampered items repaired, replaced, or otherwise returned to proper working order.

Motor vehicles are a major source of air pollutants in metropolitan areas. Vehicle exhaust contains carbon monoxide and other pollutants - volatile organic compounds and nitrogen oxides - that react to form ground level ozone. Motor vehicles emit about one-third of Southeastern Wisconsin's volatile organic compounds (mostly hydrocarbons) and about 60% of its carbon monoxide. 

Program information

The Department of Natural Resources (DNR) sets vehicle emissions standards for the WVIP, and WisDOT administers the program. Currently, WisDOT contracts with Envirotest Wisconsin, Inc. to conduct vehicle emission inspections. WisDOT audits inspection equipment and procedures at each vehicle emission test station weekly to assure accurate results. 

Required inspections are free to the motorist, as are the first two re-inspections (if needed). Subsequent inspections, as well as voluntary inspections, cost $15 each.

The WVIP conducts approximately 650,000 inspections each year. Additional program statistics are available via the latest annual report posted on the program website.

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Recent change to the license plate renewal notices in counties requiring an emission test

Did you notice something different recently? Some registration renewal notices mailed for the October and November 2009 expiration periods changed formats. Emission test requirements were printed directly on the renewal notice instead of the full sheet statement. 

If you have mailed in your renewal notice along with your fee, you may still take the emission test now if you missed it. Simply take your certificate of registration from last year into any emission test site and take the test. If you no longer have your old registration card you may take any document that has the vehicle identification number printed on it. It is as easy as that!

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All external hyperlinks are provided for your information and for the benefit of the general public. The Wisconsin Department of Transportation does not testify to, sponsor or endorse the accuracy of the information provided on externally linked pages.

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Questions about the content of this page:
Bureau of Vehicle Services, bur-veh-services.dmv@dot.state.wi.us
Last modified: October 16, 2009