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    Allison 5sp: Transmission will not shift, indicator lights not working

    Took truck to mechanic. It was a loose wire in the plug that goes into nsbu switch.
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    Allison 5sp: Transmission will not shift, indicator lights not working

    Ok, would the internal loose filter make the transmission act the way it is acting?
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    Allison 5sp: Transmission will not shift, indicator lights not working

    Update- I went out and bought a code reader. Hooked it up and it gave code p0708- (transmission range sensor A Circuit High). I erased all codes to see if that would make a difference. I started truck up and without even putting truck in gear the check engine light came on. Shut truck off and...
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    Allison 5sp: Transmission will not shift, indicator lights not working

    I forgot to mention, when changing out nsbu switch, the bigger plug had a lot of what looked like transmission fluid inside plug when I pulled it out. I dried it off before installing new nsbu switch.
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    Allison 5sp: Transmission will not shift, indicator lights not working

    I was very careful to leave alignment tool in while installing, made sure nothing turned. It acts as if I never changed it out. I took it for a test, it will go to 40 mph @ 2500 rpm. I drove it about 4-5 miles and just as I was turning into drive way the indicator lights on dash came on...
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    Allison 5sp: Transmission will not shift, indicator lights not working

    Hi all- I just bought this all stock 2002 GMC Sierra 4WD Crewcab shortbed (98K) beautiful truck, like new. All was well for a couple weeks, then transmission started acting funny. It would not shift up, can only get to 40 mph @ 2500 rpms..indicator lights quit indicating gear selection. I read...