Originally Posted by
pizzaguy
I can't remember where I read it, but the requirements seemed more extensive than that. That is to say, I don't think 50 miles is going to do it. The idea here is that if you disconnect the battery and therefore zero the parameters, if they allowed you to try an emissions test right away, you could hide issue with the emissions system.
I simply cannot remember the requirements - but I think that miles is not the issue - it's the variety of driving and temperature cycles that does it, as the requirements to get the system to interrogate or 'use' all of the monitors go beyond simply driving the car, say, at 60mph for 50 miles or so.
I use an OBDII reader on my vehicles, they show all the parameters and give you a visual indication (RED YELLOW or GREEN led) along with the codes generated (or no codes when it is ready to be tested showing a GREEN led). You will pass IF the tech disregards a 'drive cycle' reset (they know a failed RED light condition can be reset by OBDII type devices so they make sure the drive cycle YELLOW light is/are completed). I didn't know if a battery disconnect would reset a RED fail but I believe it will trigger the self-diagnostic for all the drive-cycle parameters. This will trigger the YELLOW light on OBD testing equipment, which IS an automatic fail for state emissions site testing equipment. The specific 'drive cycle' for this car MUST be completed (with no errors/codes) before that yellow light will reset to the green (passed) indicator. Any error, RED or YELLOW (self diagnostic mode-drive cycle self-tests in
Service Manual Book 3 Group 25) will fail in the states that have emissions testing. That is what I have read, and so far all the states I know that test will fail the car
until the 'drive cycle' is/are completed and 'green'. I see the drive tests parameters for the sub test(s) given, in book 3 (rear) group 25. A lot of reading, but you can associate the test to do by what your OBDII reader is telling you (mine has flashing 'DOT's" with letters in them showing the drive cycle test not yet finished. That flashing 'DOT' (or DOT's) needs to be referenced in the group 25 tests you need to do. Following that group 25 reset, the DOT that flashes should be 'steady', meaning it ran and passed. I have run other older vehicles 'drive cycles' before, they were a whole lot simpler, and when ran they reset all those 'DOTs' over its simple set driving course. This car has QUITE a complicated setup for resetting all those sensors...