Gear range sensor selector removal?

2002 BUICK LESABRE
100,000 MILES • 3.8L • 6 CYL • 2WD • AUTOMATIC
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JNUNN
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WOW!! Never in my life have I run into such a stubborn part. First, how do you unlock the part from the casing, I found the plunger or keeper. Push in or pull out? Then, do I actually have room to fish it out of casing?
Jan 3, 2026 at 1:02 PM
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STRAILER
  • ASE Certified Mechanic
  • 54,832 POSTS
  • ASE Certified Mechanic
That is called an "internal mode switch" the valve body will need to be removed to replace it. The switch is removed from inside the transmission case, here is the location of the switch for clarity. It is not the easy way of just unbolting it from the input of the selector shaft, sorry. I can help you if you upload images a short video of the problem I will walk you through the steps one at a time. Check out the images (below). Let us know how it goes
Jan 4, 2026 at 9:15 AM
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JNUNN
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Thank you for your response I do appreciate it. Unfortunately I am committed to the repair at this point, and have come to discover this is the case. I have the side cover off of the transmission and retainer pin pulled which allowed the switch to drop. Unfortunately not to the point of removal. So, my question now is do you or anyone else have any information on the frequency or likelihood of this part failing? Car was presented with a crank but no start issue, and diagnosis was done by another party. I feel I may be on a fools errand. Thanks in advance
Jan 4, 2026 at 10:06 AM
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STRAILER
  • ASE Certified Mechanic
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  • ASE Certified Mechanic
If the engine cranks but will not run then this will not be the problem. Please reassemble the car so we can find the real problem. Please start a new thread as well.
Jan 5, 2026 at 9:32 AM
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