Emission test saidOBD not ready on my 1997 Chevy Astro and I need to do a drive cycle. What are the parameters for a 'drive cycle'?

Answer 1

Motor's OBD II Drive Cycle Guide (the MIL must be off):

Step 1: Connect a scan tool and check monitor status and precondition.

Step 2: Start the engine and let it idle for at least 2 minutes.

Step 3: Drive at 25 mph or more for at least 50 seconds; be sure engine speed remains above 900 rpm.

Step 4: Stop the vehicle and allow the engine to idle for at least 40 seconds.

Step 5: Repeat Steps 2 to 4 ten times.

Step 6: Check the monitor status; it should switch to Complete. If it doesn't, be sure all enabling criteria are met.

Step 7: If the monitor has not switched to Complete, turn the ignition off and repeat Steps 2 through 5.

Step 8: The readiness status may not switch to Complete if a pending DTC is detected. Perform a second drive cycle to confirm the DTC. Once a second drive cycle is completed, a current DTC will be stored.

For information on other drive cycles of other Vehicles visit http://sinautoscan.com/forum/index.php?topic=6.0