The windows ,locks etc... are controlled by an electronic control module ,BCM - body control module . Doubt shifting into reverse or the water did anything . Shifting into reverse could have damaged the internal parts of the transmission only . Did water get inside the driver door ? Taking the vehicle to a qualified repair shop that has a professional scan tool to have a full vehicle scan done ,is what you should do . Not a part store , their code reader can not read BCM or driver door module codes .
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As Jeff points out the wires as shorting and it is a known issue due to the cable routing. I just watched the video and it is a very easy fix to put it right.
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Resetting the airbag light on your Chevy Silverado should be easy to do. Follow this video to watch it being done in a Chevy Silverado. To start with, you will:
Put the key into the ignition
Turn the key to the "on" position
Wait for the airbag light to turn on
Wait to continue until the airbag light turns off (around seven seconds)
Repeat the same steps twice more
Turn on your engine
After you take these steps, your airbag light should turn off. If it doesn't do so, then you should consider taking your vehicle in for diagnostic testing.
If the airbag light remains on, it could mean that something in the system is faulty. That could mean the airbag, the computer wiring, or another issue. Oftentimes, when the airbag light comes on unexpectedly, it is because of interference with the switch.
Feb 12, 2021
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Sounds like you have an Amazon Lemon, made in China. Find a local auto locksmith. They have a pro grade scan tool computer to check the vehicle systems and also a gadget they can test the transmitter in the fob for its functions.
https://www.google.com/search?q=local+auto+locksmith
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Yes, aftermarket alarms can cause problems like that, and remote starters are even worse. Better to stick with what the factory designed and put in.
The check engine light has a code and that will tell you what the issue is. You need someone with a scan tool.