Description of On Board Diagnostic (OBD) Drive Cycle

The following procedure is designed to execute and complete the OBD monitors. To complete a specific monitor for repair verification, follow steps 1 through 4, then continue with the step described by the appropriate monitor found under the OBD Monitor Exercised column.

Federal OBD requires that all vehicles comply with 0.5 mm (0.020 inch) EVAP system requirements in addition to meeting the 1.0 mm (0.040 inch) EVAP system monitoring requirements. Some vehicles will use the engine off 0.5 mm (0.020 inch) EVAP monitor rather than the 1.0 mm (0.040 inch) EVAP monitor to set I/M Readiness.

For the EVAP system monitor to run, the ambient air temperature must be between 4.4 to 37.8°C (40 to 100°F), and the altitude below 2, 438 meters (8, 000 feet). If the OBD monitors must be completed in these conditions, the PCM must detect them once (twice on some applications) before the EVAP system monitor can be bypassed and OBD monitors readied. The EVAP Monitor Bypass procedure is described in the following drive cycle.

Use a scan tool to carry out the OBD drive cycle. Refer to the scan tool manufacturer's instruction manual for each described function.