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Transmission or sensor problem?

This is in regard to a 2000 Chevrolet Silverado 1500 with the 4.8L engine and automatic transmission. It currently has 210,163 miles on it.

Today, I drove my truck to Costco to buy groceries, and when I got there, I pulled into a parking space, moved the transmission shifter until the “P” was highlighted, and turned the engine off. When I took my foot off the brake, the truck started to roll backward. I thought this was strange, because the park interlock has always worked for me. Anyways, I restarted the engine, moved the shifter to “D”, pulled forward, back into “P”, and this time it locked properly.

After Costco, I stopped at a gas station for fuel, and then when I attempted to start the engine again, nothing happened–no noise or anything, and the battery gauge showed about 12-13 volts, which is normal, and the headlights are still normal brightness.

I assumed the battery had gone bad, so I had my wife come in her car with the jumper cables and attempted to jump start it, and the same thing happened. So I had a tow truck come, the tow truck driver attempted to jump start it with a jump starting pack. Same result, though the battery gauge showed about 14 volts this time, so I had it towed home.

Once at home, I started playing around with it, and eventually discovered that while the shifter should be in “P”, none of the gear selections are highlighted on the display. I can cycle through all of the gears: “R”, “N”, “D”, “3”, “2”, “1” can be selected, but not “P”. When I shifted into “N”, the engine was able to start.

So the problem is that when I move the shifter from “R” to “P”, it feels different, like something is not engaging properly. It could be my imagination, though. I have no idea if the gear selector position is sensed at the steering column or inside the transmission on this model. Any ideas would be appreciated.

I am thinking a broken parking pawl in the transmission. Fixing it will require the transmission to come out and overhauled from what I know/think.

Since you probably have to push the brake pedal to get the trans into gear, you might have a problem that’s related to whatever makes that work.

Here is what the display looks like, when it should be in “P”.

It starts in neutral and it feels funny shifting from reverse to park.

This tells me the transmission is not being shifted all the way into park. You have probably have linkage or cable problems. Or the shift mechenism on the transmission is restricted. Your parking pawl is fine.

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Check if the shift lever at the park/neutral safety switch on the transmission has come loose.

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Tester

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I didn’t see anything loose or damaged. I think there might be something wrong with the steering column or perhaps the shift cable assembly. I took my truck to the transmission repair shop today. I will update once it is fixed.

Going to agree with tcmichnorth. It sounds like the linkage needs to be adjusted.

and if it does, I might suspect a bad cable. some of the newer Chevy’s have a 2 piece cable for ease of replacement (not sure about yours.)

I had this happen on a 2010, and the plastic bushing that holds the cable end onto the shift selector on the transmission dried out and broke. was able to find a bushing online and replace just it.

It ended up being the transmission shifter cable. The transmission shop was able to obtain the part from a local Chevrolet dealer who had it in stock. It was not an expensive repair.

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That is a good way to start 2021 with good news and an inexpensive repair.

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Glad to hear it. Happy motoring.