New transmission, now getting P1870

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xjsc16x

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02 Tahoe LT with 209k miles. Transmission let go earlier this year, was off the road for a while and put a new one in that was rebuilt with some upgraded parts by a guy off Craigslist. For $500 I figured it was worth the shot.

Transmission is in, started driving it last week drives and shifts great only problem is every once in a while the 1-2 shift is really hard. I have not tried adjusting anything only been driving it since Monday and now I pulled a P1870 code this morning.

Does this sound like the typical loose TCC apply? Is there anything else I could look for?

And what does everyone recommend to fix it if that is the problem? Would a transgo shift kit address this? I could consider getting it installed if it would. I'd rather not mess with valve bodies myself.

Thanks,
Justin
 

Mechanic421

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02 Tahoe LT with 209k miles. Transmission let go earlier this year, was off the road for a while and put a new one in that was rebuilt with some upgraded parts by a guy off Craigslist. For $500 I figured it was worth the shot.

Transmission is in, started driving it last week drives and shifts great only problem is every once in a while the 1-2 shift is really hard. I have not tried adjusting anything only been driving it since Monday and now I pulled a P1870 code this morning.

Does this sound like the typical loose TCC apply? Is there anything else I could look for?

And what does everyone recommend to fix it if that is the problem? Would a transgo shift kit address this? I could consider getting it installed if it would. I'd rather not mess with valve bodies myself.

Thanks,
Justin
Take it to a professional for diagnostics and then go from there. Could be a number issues line pressure, tcc solenoid , tcc valve or maybe pressure control solenoid.
 
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Rocket Man

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That's an awesome video. I love it when they're detailed like that. Unfortunately like @Mechanic421 said it could be any number of components. All the code tells you is the input and output speeds are far enough off to set a code. Something is slipping.
 
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xjsc16x

xjsc16x

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Take it to a professional for diagnostics and then go from there. Could be a number issues line pressure, tcc solenoid , tcc valve or maybe pressure control solenoid.

Definitely going to have to. One thing I know better than go messing around in is a valve body. I hope it's something as simple as a solenoid because my wallet's not exactly feeling very heavy lol.

-Justin
 

Mechanic421

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Definitely going to have to. One thing I know better than go messing around in is a valve body. I hope it's something as simple as a solenoid because my wallet's not exactly feeling very heavy lol.

-Justin
If you google 4l60e harsh 1-2 shift and code p1870 there are some websites with some good information.
 
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xjsc16x

xjsc16x

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If you google 4l60e harsh 1-2 shift and code p1870 there are some websites with some good information.

I've done some, seems that the TCC apply being loose is a fairly common cause which is why I asked about that. Guess the only way to find out is when the tranny guy tells me
 

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