Hello everyone. I was hoping that someone here could help me with a problem that I can't seem to fix.
I've got a 1999 non-supercharged Millenia. The speedometer read-out started to get a little jerky and then stopped moving at speeds under about 65mph. Above this, it will start to move but it still isn't reading what it is supposed to.
In addition, the mileage reading is also acting the same way: not moving at slower speeds.
I have replaced the "speedometer" sensor that mounts on the wheel, where the little teeth are located that it senses going around. This was not a new sensor, but off a junkyard car.
I have also replaced another "speedometer" sensor that is mounted on the transmission, right underneath the top transmission mount (which had to be removed to get to it). This was new.
I have ALSO replaced the instrument cluster. NONE of this has fixed it!
Is there another sensor that I am not aware of? I've found something on the internet; another sensor that has a red worm-gear at one end, but I haven't been able to find it on my car.
If anyone is familiar with this problem, PLEASE help! Thank you!

 

Firewall side on the transmission near where the passenger side axle goes into the transmission. One 10mm bolt holds it in. The sensor you replaced was a turbine sensor that monitors drum speed.

 

Thank you Hixx! I was under the car yesterday looking in that area, but wasn't able to find anything. Now that I know that there IS something there, I'll give it a closer look.

 

Actually if you remove the intake/aircleaner boot you can get to it from the top. Check the wires going into the connector closely. I have seen them come apart there.

 

Okay. I'll do that. Thanks again.

 

I worked on my car today and found that guy! It's not hard to find once you know where it is. Hixx is right; it's very close to where the passenger driveshaft goes into the transmission. I found that by removing the battery tray and taking the wires off the starter(?) made it easier to get to. It's a little under the intake manifold as well; sort of in a nitch. Unfortunately, cleaning the part and connections didn't fix it. The wiring was also good. I can't afford the $150 price tag for a new sensor, so I'll be checking out the junk yards around town to see if I can find a used one.

 

Thank God you bought the expensive extended Mazda warrantee! This repair is covered and will not cost you a dime!

 

I just wanted everyone to know that i found another speedometer sensor at a salvage "pull a part" lot. The cashier had a rather puzzled and bored look on her face as I showed the part to her and asked me what it was. I told her a sensor on a Mazda Milliena. She generously let me have it for free.
Anyway, I put it on today and I now have a working speedometer once more! hurray!
thanks again Hixx for your help!