Drivetrain - Need Trans Help!!! | Ford Escort Owners Association (FEOA)
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Drivetrain Need Trans Help!!!

Discussion in 'Drivetrains' started by 93 green wagon, Sep 16, 2015.

  1. 93 green wagon

    93 green wagon FEOA Member

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    Anybody tell me how to test the speed sensor on on 93 tracer auto trans. speedo works fine. need to check if it is sending signal to pcm. Will it check if ohm meter says no resistance? Have a shift problem where it won't come out of first gear. No power to 1-2 Solinoid from pcm. replaced pcm same problem. Speed sensor must not be sending signal to pcm? can I check with ohm meter?
  2. denisond3

    denisond3 Moderator Staff Member

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    Sort of:
    Assuming you can get the VSS out of the car, you can put a voltmeter across the two pins inside the connector on the VSS, and twirl the plastic gear. Using an analog meter, you should see the needle move a little upscale if the meter is set for Alternating Current, and if measuring on the Direct Current scale the needle should wobble a little bit around the zero. The problem is that I dont know what decent voltage responses would be. I have a spare that I use for comparison. If a VSS gives similar readings to my spare I figure its good. One of them I tested showed much less movement of the meter needles when I spun the gear with my fingers; but that VSS had come from a 5-speed, where it doesnt affect shifting. I never measured the resistance of the VSS. If its problem was a loose or tracked permanent magnet, the restistance reading wouldnt show that.
    On the 2nd gen Escorts, the speedo is mechanically driven via the cable. Therefore the electrical part could be bad (or the connector to the wiring harness or the pair of wires could be bad), and the speedo would still work okay.

    Years ago a couple of forum members had the following 'failure to upshift'.... The trans would stay in first gear too long, even at high engine speed - and then finally agree to shift normally. This meant they had to run around for a couple of miles and several minutes with the engine screaming, until the trans chose to upshift from first. For the rest of the day or at least the rest of the time the engine was running the trans would be okay. The next morning, or the next time the car sat - it would again fail to upshift from first, until it had had another session of misbehvaior.
    I dont recall that those members ever solved their problem - or I missed the update posting if they did.

    It could have been a faulty VSS of course. But with any 2nd gen. Escort being 18+ years old, the VSS may be stuck in the transaxle housing from corrosion. Its plastic upper part can break apart before pulling the aluminum lower part out of the hole where it fits into the back of the transaxle. Getting a stuck VSS out can be hard work. I have worked on 8 Escorts transmissions - and 7 of them had VSS that were stuck. I was able to extract one of them with the transmissions still in the car - but the engine was out, so I was able to stand in the engine bay to do the fight. With the other 6, I had the transmission out of the car and on my workbench; where it was still a tedious task to get the VSS out and the corrosion filed away.
    Six of these were automatic transmissions. Two were 5-speed trans, where removal of the VSS is how you check that the transmission still has fluid in it. I do this check once a year.
    With the 94LX I am working on now, its transmission had no more than 1/4 pint of trans fluid in it, but at least it wasnt rusty inside. The prior owner sold the car to me because (among other problems) her mechanic said the transmission had to come out of the car in order to get the VSS 'fixed'.

    I replaced the connector to the VSS on one Escort. It had not failed yet, but the ears that hold the connector onto the VSS were both broken off.
  3. zzyzzx

    zzyzzx FEOA Member

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    If you have cruise control, and it works, the VSS is good. The cruise control uses the VSS signal as an input.
    bent_rod and denisond3 like this.
  4. 93 green wagon

    93 green wagon FEOA Member

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  5. 93 green wagon

    93 green wagon FEOA Member

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    Thanks for all the info! I have no problem removing VSS. Have tried three units from different trans I have. Have found same reading on ohm meter on all to be same. reading is .200 on all when on bench. All feel smooth and tight.My issue is PCM is not powering Green/black wire out to 1/2 soloniod to make it shift to 2nd. Can take 12 volt wire and power green wire and it will shift!! Have changed PCM and still same!! missing something? Anyone can help I'm buying the beer!! Thanks Guys!!!
  6. 93 green wagon

    93 green wagon FEOA Member

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    Have found a good wire diagram of PCM and now will check if VSS is getting proper voltage and ground out of PCM. All idea's will be helpful! Thanks again!!!
  7. bent_rod

    bent_rod FEOA Donator

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    Bad grounds on Escorts are a big problem. Be 100% sure of clean and solid ground connections at the connection point of several small ground wires at the battery ground lug. One of the small ground wires in that group goes directly to the PCM and others supply grounds for engine control systems.
    I would be looking for a solid ground circuit to the VSS connector plug.
    Next check the signal wire from the VSS to the PCM plug.
    After that check the wire from the 1-2 solenoid back to the PCM plug.
    All the above circuits should have good low resistance connections.
  8. 93 green wagon

    93 green wagon FEOA Member

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    Thanks pal! have ckecked all grounds and added ground wire to bellhousing. Have to check VSS wire and plug. This thing is beating my ass! Tomorrow is another Day!
  9. zzyzzx

    zzyzzx FEOA Member

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    Bad piece of wire? Bad connection at PCM?
    Exactly where did you apply the power? At the PCM end or at the transmission housing end?

    Obligatory:
    [​IMG]

    Ripped off from this thread:
    https://www.feoa.net/threads/how-to-replace-1-2-shift-solenoid-on-atx-1991.82837/
  10. 93 green wagon

    93 green wagon FEOA Member

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    Thanks for all the help guys! Finallly found issue. The plug to VSS two wire with factory tape wrapped all the way to top of plug so you can't see where they go into plug.Found white/black wire.POS wire from PCM. Was broke right on top plug where not visual.My Trans guy. Factory Ford guy brought OBD-1 scanner and read real time while test driving. found no input from VSS. Checked plug that I have looked at 25 times and wire was broke right at plug. Tape on two wire harness was so tight that can't even see wire going into plug!! Stripped tape off, cut both wires. found new round conn. and replaced in old plug. Shifts like a dream!! Amazing that one little wire that you really can't see can make you want to give up!!Thanks again guys! I've learned alot about electrical wiring and PCM ops.
    zzyzzx likes this.
  11. denisond3

    denisond3 Moderator Staff Member

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    Glad to hear your found what the cause was, and fixed it. As our Escorts age, I expect that bad wires in the harness will continue to happen more.
  12. Maxwelhse

    Maxwelhse FEOA Member

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    FWIW, you may want to go over your repair with a generous helping of liquid electrical tape. It will create a strain relief on the connector and help prevent the problem from ever happening again.
    bent_rod likes this.

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