My car needs a smog check, but the speedometer/odometer isn't working?

there are a few reasons why the speedometer would stop working. One of them would cause your car to fail emissions inspections. Here are a couple things to check to get your speedometer working again:

1) plug in a code reader into the OBD2 port. This is not to get any codes necessarily, instead it is to determine if power is available to that port. The OBD2 port and the speedometer share the power wire from the fuse box under the hood. Plugging in a code reader will easily determine that this wire is supplying power to both items.

2) the vehicle speed sensor (VSS), or its circuit, has failed. The VSS is on the top of the transmission just above the axles. It is sometimes difficult to remove due to corrosion so soak the retaining bolt with pb blaster or wd-40 before trying to remove. The VSS is different for automatic and 5-speed transmissions so be sure you replace it with the correct one if replacement is necessary.

3) the fuse on the interior fuse box labeled "meter" needs replacement. This may be it, but a bad fuse would cause the car not to charge properly and you would have noticed the problem when the car lost its charge.

4) if car is equipped with cruise control-- does the cruise still work? If so, then review the first option. Cruise control will still work when the power wire mentioned in #1 is not providing power.

5) the speedometer just stopped working. This is not likely the cause. I have seen many ZX2s go beyond 400,000 miles and still have a working speedometer.

These are the main reasons why the speedometer would stop working. The odometer is part of the speedometer assembly. Both these things work together and is the reason why both do not work at the same time.

As far as passing emissions testing, of all the things mentioned only #1 would cause the car not to pass. The reason it wont pass is not because of being able to gauge speed, instead it will be due to no power at the OBD2 connection. Without this connection the scanner the inspectors use will not be able to determine whether or not everything is functioning as intended for purpose of emissions testing.

If you live in a state which has vehicle inspections which include emission testing, then a non-functioning speedometer would be cause for not passing. Whether or not it passes due to this will be solely up to the inspector.

I hope this helps, I had the same problem with my 99 and #1 was the reason

well the good news for you is they go by rpm so get down there and get through smog. Fake it until you make it keep your outh shut and unless it comes up and tell them it just happened a few days before and its going in the sho next week. What else can you say? it is not your fault your mechanic is busy.good luck dont make a hapit of lying but get the job done would ya?

The tester doesn't USE your speedo, he looks at the monitor on his machine, so don't sweat it.

It MAY need to at least display a number on the odometer, as I think they record the displayed mileage.

take to station that just does tail pipe .or just fix speedo