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Is my car's PCM/ECM going crazy and i'm just chasing ghosts here?

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    Is my car's PCM/ECM going crazy and i'm just chasing ghosts here?

    Hi everyone!
    I've been experiencing something really weird with my 1995 Protege 1.5L MT(5-speed) lately. If anyone has any ideas or suggestions, i'd like to hear them.

    I guess i'll start from the beginning:

    About three weeks ago a CEL on my Protege came on with absolutely no symptoms. The car ran just fine. Went to Autozone to have the codes pulled. Came up with code P0335 Crankshaft Position Sensor ”A” Circuit Malfunction.
    Before rushing to buy a new crank sensor, i referred to my repair manual to see if there was any way to test the old part somehow. And indeed there was......you test the A and B connectors with Ohmmeter, and anything between 500-600 Ohms is normal. My old crank sensor tested just fine. I also adjusted the air gap, but the CEL still came on with the car running just fine.

    Just kept on driving the car when one day the CEL started blinking with the car running just fine. Had the codes pulled again. In addition to P0335, it also came up with P0300 Single/or random misfire. Erased the codes and to this day haven't seen a blinking CEL again.

    I then bought a new Crank sensor, just in case. But the CEL came back soon after with the car running just fine again. Went back to Autozone to have the codes pulled. And again it gave me that P0335.
    I was really puzzled at that point, and while passing O'reillys one day, i decided to check the CEL there. And the funny thing was that their OBD-II reader gave me a new code - P2422 Evaporative Emission (EVAP) System Vent Shut Valve Closed. The crank sensor code wasn't showing up with that scan, just that one P2422.

    On my way home from O'reillys, i decided to go by Advance Auto Parts, and see what their code reader says. Their's gave me that old P0335 again, but no P2422.

    At that point i believed that it must have been that Purge Valve and not the crank sensor. I thought that maybe O'reillys code reader was more compatible with my car, or something.
    Being pretty sure that i had finally found what was wrong, i decided to buy a new purge valve. I paid good money for it cause it's a Mazda Dealer part only.

    A week later the part arrived, i installed it, erased the codes and started the car. About 10 seconds later the CEL was on again with the car running just fine. Boy, was i stunned at that point.....LOL.

    Anyway, i just kept on driving until while passing O'reillys again, i decided to borrow their code reader again. And this time it came up with three new codes with the car STILL running just FINE:

    P0730 - INCORRECT GEAR RATIO
    P0715 - INPUT/TURBINE SPEED SENSOR
    P0722 - OUTPUT SPEED SENSOR CIRCUIT NO SIGNAL

    Now i'm really puzzled. Mine has a manual transmission, can these codes really be relevant to me? All these three codes seem to indicate one problem - a faulty Vehicle Speed Sensor, you know, the one that connects to a transmission. Does anyone know where that speed sensor is on a manual transmission, cause i looked and couldn't see anything like that connected to my gearbox? There's just one thing that connects to the gearbox, and that's a backing up light sensor/switch. I even went to O'reillys, Autozone, and AAP, and no one had that part for my car. It wasn't even showing up on their computers. All that makes me think that my gearbox doesn't even have that Input/Output Speed Sensor thingy. Am i wrong?
    Anyone have any ideas as to what's going on? Could it just be a faulty PCM?

    #2
    uh

    Comment


      #3
      I have had much trouble with my CEL. It was on for a while then would cut out for a while. Then it would come on, then cut off. Just two days ago it started blinking so I plan on going AutoZone and get them to run a code reader to see what is happening

      Comment


        #4
        The speed sensor is on the top of the transmission towards the backside.
        1997 Protegé ES: The Power of BP

        Broke Status FTW!

        Comment


          #5
          Originally posted by Henchman View Post
          The speed sensor is on the top of the transmission towards the backside.

          Thanks! Let it also be said that i have been to several places several times to have the codes checked, and everywhere i go, i get the P0335 (Crank pos. sensor) code, except one place - O'reillys. There's more than one O'reillys store in my town though. The two O'reillys stores i've been to, the code reader in one of them is the one giving me a different code every time.

          Since i had already bought two new Crank pos. sensors, i became pretty sure that it could not have been that part that was faulty, and started looking more into the other codes that that one reader was coming up with.
          But now i am convinced again that it IS the crank pos. sensor that has something wrong with it. Well, maybe not the part itself, but something related to that. The Car drives fine, just the CEL that comes on, then goes off for a few drive cycles, then comes back on again.

          Comment


            #6
            The CEL for the crank sensor is probably since the spacing between the sensor and crank is too much.
            1997 Protegé ES: The Power of BP

            Broke Status FTW!

            Comment


              #7
              Originally posted by Henchman View Post
              The CEL for the crank sensor is probably since the spacing between the sensor and crank is too much.
              That's what i thought too, but after many adjustments CEL is still on. I even adjusted it so close once, where it actually almost touched the notch on the pulley.

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