After replacing the transmission fluid and filter, the transmission truck will not shift out of park?

2000 CHEVROLET TAHOE
200,000 MILES • 5.3L • 4WD • AUTOMATIC
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MOSSMAN_62
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  • 3 POSTS
After changing transmission fluid and filter truck won't come out of park.
Apr 27, 2023 at 10:38 AM
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JACOBANDNICKOLAS
  • CAR REPAIR CONTRIBUTOR
  • 110,190 POSTS
Hi,

The idea that you simply changed the fluid wouldn't have caused it. Something has either come disconnected or caused a fuse to fail.

If you look at pic 1 below, I attached the wiring schematic for the shift interlock circuit. I need you to first confirm that the brake lights are working. The shift lock actuator is powered through the brake light switch.

If they aren't working, check the fuse I highlighted in the picture. In addition to checking the fuse, confirm there is power to and from it.

Here is a link you may find helpful:

https://www.2carpros.com/articles/how-to-check-a-car-fuse

If you look at pic 2, it shows the location of the park/neutral switch. Check to make sure nothing has come disconnected or was damaged.

Let me know what you find.,

Joe

See pics below.
Apr 27, 2023 at 7:15 PM
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MOSSMAN_62
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Thank you for your help. We did get it to come out of park. But we are also having problems with the battery. It continued to need to be charged when we were working on it. Once charged we are having a couple of other issues. When trying to start it. It does nothing. It will do that a couple times then it will start. Also, can you tell me if the Dextron 6 was the correct fluid for my truck? That' is what the parts store said was recommended. Thank You Any help is appreciated.
Apr 28, 2023 at 4:55 PM
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JACOBANDNICKOLAS
  • CAR REPAIR CONTRIBUTOR
  • 110,190 POSTS
Hi,

The vehicle originally had Dextron III, but the Dextron 6 covers it. No problem with that. (See pic below)

If the battery needs to be charged, something has a draw on it. Take a look at this link. It explains how to test for a draw. Check around the transmission to make sure by accident a wire wasn't pinched.

https://www.2carpros.com/articles/car-battery-dead-overnight

Let me know what you find.

Joe

See pic below.
Apr 28, 2023 at 10:52 PM