Drive Clean Test and Repair Centre

Drive Clean Modernization

Drive Clean plays an important role in safeguarding Ontarios air quality by identifying excessively polluting cars and trucks with emissions problems and requiring them to be repaired. While todays vehicles are cleaner through advances in emissions technology, all vehicles require regular maintenance to keep them operating properly.

Over the past decade, Drive Clean has tightened emissions standards and focused the program on the vehicles that are most likely to pollute. On January 1, 2013, Ontario introduced changes to the emissions test to make the Drive Clean program even better. The new test takes advantage of the computerized monitoring equipment in todays technologically advanced vehicles.

The modernized Drive Clean program will provide significant benefits by:

  • Providing a faster, more accurate emissions test;
  • Identifying vehicles with emissions systems failures before they become gross polluters
  • Identifying emissions systems problems for more effective repairs;
  • Reducing more smog-causing pollutants from vehicle emissions; and
  • Minimizing fraud.

Computerized Emissions Testing Equipment

On-board diagnostic (OBD) testing is a computer-based emissions test that interacts with the manufacturer-installed computer that continuously monitors a vehicles emission components. When a vehicles OBD system detects an emissions related malfunction, a Diagnostic Trouble Code (DTC) is stored in the on-board computer. The presence of a DTC indicates there is something wrong with the vehicles emissions control system and it needs to be repaired. The Drive Clean test equipment connects to the OBD computer and retrieves diagnostic information as part of the vehicle emissions inspection.

On-board diagnostic computers became standard in Canadian light-duty vehicles in 1998. Drive Clean will continue to use a tailpipe test for light-duty vehicles from 1988 to 1997 model years to ensure that grossly polluting older vehicles are identified and repaired. Heavier light-duty SUVs or pickup trucks (3,856 4,500 kg) of model years 1988 to 2006 will also receive a tailpipe test as they are not equipped with OBD technology.

The test for heavy-duty vehicles has not changed, but an advisory OBD test has been introduced for newer vehicles built with this technology. This will provide owners with helpful information about the health of their vehicle.

Understanding Readiness

The OBD system has monitors that check the performance of various emissions-related components and systems while you drive. Some of the monitors will only check components or the system at the point when certain driving conditions are met. Usually, a combination of local and highway driving will turn on all monitors.

A monitor is considered Ready when it successfully completes a check. If a monitor has not or cannot complete its check it will report Not Ready. Monitors that have completed their checks typically stay Ready and do not become Not Ready on their own.

The new OBD test for Drive Clean will allow two monitors to be Not Ready if the vehicle model year is 1998 to 2000; and one monitor to be Not Ready if the vehicle model year is 2001 or newer. If more than the allowed monitors are Not Ready, the vehicle will not pass the OBD emissions test.

Reason for being Not Ready

A monitor being Not Ready does not necessarily mean that there is a problem with the vehicles emissions system. A monitor may not be Ready in the following situations:

  • If a vehicle has recently been serviced where the battery was required to be disconnected.
  • If a vehicle's battery has recently been replaced.
  • If the battery has been drained i.e., leaving the headlights on.
  • If, after repairs, the vehicle has not been driven under the conditions to run all monitors.

Addressing Readiness

If a vehicle cannot pass the test because it is Not Ready, it will need to be driven under various conditions (drive cycles), to allow the OBD computer to fully check the emissions systems. A few days of combined city and highway driving will normally allow the OBD monitors to run and become Ready.

Most vehicles with no emissions control system problems can become Ready within minutes of normal driving. Vehicles with emissions control system issues will take longer to become Ready. Talk to your Drive Clean facility staff about the best way to get your vehicle Ready.

Once Ready, there may be an emissions problem that will cause the vehicle to fail the Drive Clean emissions test. A vehicle with an emissions control system problem may be difficult or impossible to get Ready and could require repairs to get Ready.

Malfunction Indicator Light (MIL)

When an emissions problem is detected on an OBD equipped vehicle, an instrument panel warning light called a Malfunction Indicator Light (MIL) turns on to alert the driver. The purpose of the MIL is to warn the driver of an emissions related problem that needs to be repaired. A vehicle with a MIL on has an emissions control system problem and will need to be repaired before it can successfully pass a Drive Clean retest.

On some vehicles, the MIL will appear as a yellow engine symbol, CHECK ENGINE or SERVICE ENGINE SOON alert. Most vehicles use the following symbols:

During normal operation, the MIL will turn on for a few seconds when the engine is first started and turn off when the engine is running. If the MIL remains on, the OBD system has detected an emissions control system problem. The OBD system will automatically turn off the MIL if it no longer detects a problem.

For more information about the Drive Clean emission test please visit or call 1-800-758-2999.