E-Check and Failed E-Check Diagnostics
In January 1996, the State of Ohio began a new vehicle emissions testing program, E-Check, designed to identify motor vehicles that emit excessive levels of pollutants into the air. Among the other emissions control options considered by the legislature, E-Check was the most cost-efficient measure to reduce the volatile organic compounds (VOCs) that form ground-level ozone, or smog. The program currently tests cars in seven Ohio counties.
At the time it was implemented, E-Check used the I/M 240 test, a 240-second transient test during which a vehicle is driven on a dyne (treadmill) and its tailpipe emissions are measured. In 2000, the I/M 240 test was replaced with Acceleration Simulation Mode (ASM) 2525. ASM 2525 is similar to I/M 240 but is perceived to be less stressful on the vehicle. Testing programs, like E-Check, that employ one or more of these tests are referred to by U.S. EPA as "enhanced" programs.
In January 2004, a new, federally mandated test known as On-Board Diagnostics (OBD II) was implemented. OBD II is required for newer vehicles, while ASM 2525 is still used for older vehicles. For more information on OBD II click here.