Transmission issue, jerks when put in reverse, will not change gears

2003 KIA OPTIMA
195,724 MILES • 0.7L • 6 CYL • 2WD • AUTOMATIC
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SANDY555
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I had code read all that's showing is a vacuum leak .
Nov 6, 2019 at 9:01 AM
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DANNY L
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Hello, I'm Danny.

Can you provide us with the code so we can properly diagnose the problem? This will help.Thanks for using 2CarPros.
Nov 6, 2019 at 6:09 PM
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SANDY555
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The shop I took it to didn't give me the code.just told me is was showing a vacuum leak.
Nov 6, 2019 at 6:47 PM
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SANDY555
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We fixed what we hoped was causing the vacuum leak. car still not shifting.
Nov 7, 2019 at 9:38 AM
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STRAILER
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We will need the code number to help you fix the problem. here is a guide to help you get the codes:

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

Please run down this guide and report back.
Nov 9, 2019 at 12:59 PM
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SANDY555
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I was finally able to get the code; it is p1602.
Nov 15, 2019 at 3:28 PM
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DANNY L
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Hello again,

It sounds like you are having a problem with the TCU (transmission control unit). I've attached a diagnostic chart below to help test.Hope this helps and thanks for again for using 2CarPros.
Nov 15, 2019 at 4:52 PM
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SANDY555
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My hot battery cable was extremely loose is there a way to reset the TCM.
Nov 16, 2019 at 6:32 AM
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STRAILER
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You can just clear the codes and it should reset. here is a video to show you how:

https://youtu.be/ahK_eucFi-k

Please run down this guide and report back.

Nov 16, 2019 at 11:00 AM
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SANDY555
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Had the code cleared.shifted good ..but when I started the car back up again had the problem again
Nov 16, 2019 at 11:15 AM
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DANNY L
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Hello again.

By just clearing the code if there is a fault the condition will keep showing up as in the case here until the repair is completed.It sounds like you are having an issue with the TCM (transmission control module) I will re-attach the diagnostic procedure again below.Hope this helps and thanks again for using 2CarPros.
Nov 17, 2019 at 4:18 AM
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SANDY555
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Okay, thanks for your help. trying to fix it myself as my husband is disabled and don't have the money to put it in the shop.
Nov 17, 2019 at 5:01 AM
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STRAILER
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Please let us know what you find. We are interested to see what it is.
Nov 17, 2019 at 10:50 AM
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SANDY555
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Okay, will sure let you know.
Nov 17, 2019 at 11:17 AM
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DANNY L
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Hello again,

Hoping it just could be a wiring issue. However, just to prepare you a new transmission control module from a Kia dealership is $940.00. Let us know what you find out.Thanks again for using 2CarPros.
Nov 17, 2019 at 3:10 PM
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SANDY555
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Thank you for all your help. It will be a while before I can afford one of those.
Nov 17, 2019 at 3:12 PM
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SANDY555
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We found the hot battery cable end was loose on the battery yesterday.
Nov 17, 2019 at 3:14 PM
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DANNY L
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Hello again,

After you tighten the cable let us know if the symptom returns.If so, please use the transmission control module diagnostic chart I've attached previously.Hope this helps and thanks again for using 2CarPros.
Nov 17, 2019 at 7:46 PM