Any of you guys know what is typically required for the OBD-II systems to be "ready" for an emissions test? Car is a '99 Subaru Impreza RS.
I know that there's usually some drive cycle conditions that need to be met, a few on/off cycles and some number of miles(?).
The reason I ask is that the vehicle speed sensor is disconnected so the ecu won't be logging miles. Is this going to keep the OBD system from being ready for an emissions test?
Its going to set a code, which will illuminate the MIL, which should disqualify it, wouldn't it?
I know some places, as long as the light isn't on, it passes. Others hook up just to see if the readiness monitors are ready, then pass/fail from that data nugget.
Yes the vss will set a code that will keep you from passing. The quickest way to set your readiness monitors is to drive for about 15 min at about 55 mph with minimal throttle angle changes. The temp needs to hit 150 or 180( I can't remember which) and you need to keep a steady speed. You could also drive with the test connectors plugged together, but I don't like that because I'm too paranoid to drive with a flashing cel. Force passing the monitors is also an option( though not legal).
Why are you trying to keep the ECU from logging miles, anyway? Regardless, yes a disconnected VSS will flunk your emissions test and it will also make the car hit fuel cut in super weird places, at least on my '98 2.2 it did.
SlickDizzy wrote: Why are you trying to keep the ECU from logging miles, anyway? Regardless, yes a disconnected VSS will flunk your emissions test and it will also make the car hit fuel cut in super weird places, at least on my '98 2.2 it did.
Because they fail pretty often and are expensive? Thats one reason i can think of.
Ok, thanks guys.
The reason I don't have one installed at the moment is because I just finished swapping in a '99 engine/harness/dash but the chassis and trans are '98, so the VSS isn't the same. I'll order the right one and get it installed this week.
Thanks again for the help.
SlickDizzy wrote: ...it will also make the car hit fuel cut in super weird places, at least on my '98 2.2 it did.
Yeah this has happened twice - hopefully it's just the VSS and not one of the other sensor.
Drive this trace http://www.dieselnet.com/standards/cycles/ftp75.php
All of the monitors are required to run in one test.
The vehicle speed sensor is used to determine if a monitor is ready to run for a few tests.
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