Only a registered DriveON technician using approved equipment at an authorized facility (including an authorized mobile facility) may perform a valid inspection. The steps below summarize what typically happens; the official procedure and any abort conditions are set by Ontario.
Before measurements begin, the yard or work area behind the vehicle is checked for clearance and the vehicle is positioned and secured. A stationary vehicle with an unobstructed exhaust path is a basic requirement of the SAE J1667 procedure. Safe access and suitable testing conditions must be available; not every parking spot or dock is appropriate.
A heavy-duty diesel emissions inspection includes a pre-test check. Examples Ontario identifies include confirming VIN, checking for visible emissions issues, exhaust leaks, fuel and DEF caps, governor malfunction or maladjustment, safety concerns, and — when OBD applies — access to the OBD connector. During the pre-test check, the technician confirms that the engine speed governor is not malfunctioning or visibly maladjusted.
The engine must be at normal operating temperature as required by the procedure. Approved opacity equipment is positioned at the exhaust outlet according to the DriveON / SAE J1667 requirements. A short idle alone does not automatically mean the engine is ready.
With the engine at normal operating temperature and idling, the throttle is opened from idle for the snap-acceleration event while the light-extinction opacity meter records the required readings. Ontario's DriveON program applies this procedure, referenced under O.Reg. 169/22, to heavy-duty diesel opacity testing.
It is a standardized snap-acceleration opacity procedure. Eligible vehicles may also receive an OBD system test or OBD data collection according to model year and GVWR — OBD does not replace opacity for qualifying heavy diesels.
The approved equipment records the required snap-acceleration readings and calculates the overall opacity result according to the DriveON procedure. It is safer not to describe the outcome as a single peak reading alone; Ontario refers to the overall opacity result compared with the applicable limit for the vehicle.
The result is submitted to the DriveON system. A fail report identifies the failed inspection component or recorded result, but further diagnosis may be required to determine the underlying cause. Problems should be evaluated and repaired before retesting.
The technician may not start or may interrupt the test when vehicle condition blocks a valid procedure, there is a health or safety risk, the test may damage equipment, property or the vehicle, or the pre-test check finds a problem that must be corrected first. Related guides: how mobile emissions testing works and how opacity and OBD testing apply. Book through Piotr Service.
