Wher is the transmission solenoid located

The shift solenoid on a 2012 Chevrolet Impala is located inside the transmission. It is typically located near the top of the transmission, near the shift lever. In order to access the shift solenoid, you will need to lift the vehicle and remove the transmission pan. The shift solenoid is usually mounted on the side of the transmission and is connected to the transmission control module or the transmission valve body.

It is important to note that the location of the shift solenoid can vary depending on the specific model and year of your Chevrolet Impala. If you are not familiar with automotive repair and are unsure how to locate the shift solenoid, it is recommended that you seek the help of a professional mechanic.

If your talking about the shift solenoids in the transmission, they are located on the valve body and will require removal of the transmission cover. If your talking about the BTSI (brake transmission shift interlock solenoid this is located on the shifter module.

The solenoids are usually on the inside of the transaxle.
You can look up the part on one of the parts store websites and see what it looks like.

All of the transmission shift solenoids are located inside the transmission and are attached to the transmission valve body hydraulic control plate.

CODE P1775 - A / T OR AUTOMATIC TRANSMISSION SWITCH LATCHED IN TCC POSITION. CODE PO732 - A / T ADDITIONAL GEAR RATIO ERROR IN SECOND GEAR. CODE PO700 - AUTOMATIC TRANSMISSION CONTROL SYSTEM MALFUNCTION CODE PO456 - EVAP SYSTEM SMALL LEAK DETECTED.POSSIBLE CAUSE FUEL TANK CAP LOOSE OR DAMAGED , SMALL LEAK PRESENT SOMEWHERE IN EVAP SYSTEM. I DID NOT SEE CODE P1788. BUT CODES P1775, P0732 , PO700 , YOU HAVE INTERNAL TRANSMISSION PROBLEMS TRANSMISSION SHOP HAS TO HOOK DIAGNOSTIC EQUIPMENT TO CHECK TRANSMISSION PRESSURE SOLENOIDS AND SHIFT SOLENOIDS. TRANSMISSION VALVE BODY HAS MANY SOLENOIDS PRESSURE SWITCH AND SENSORS COST TOO MUCH REPLACE THEM ALL LET GARAGE SCANNED TRANSMISSION BE MUCH CHEAPER.

Actually, the Torque Converter Clutch Solenoid is located within the transmission housing that is easily accessible through the transmission oil pan. The TCC solenoid may vary in location dependent upon manufacture but generally it is located as aforementioned. It can cause your vehicle to stall if stuck open or close because it controls loads to the engine via your torque converter which is located between the vehicle's engine and transmission. Also, make certain that you attempt to change the transmission fluid and filter before changing the TCC solenoid because that may be your underlying issue. If not, simply reuse your fresh oil and change the TCC soleniod.

A transmission solenoid is an electro-hydraulic valve that controls fluid flow into and throughout an automatic transmission. Solenoids can be normally open or normally closed. They operate via a voltage or current supplied via the transmission computer or controller. Transmission solenoids are usually installed in a transmission valve body, Transmission Control Unit, or transmission control module.

P0753 means your powertrain computer detects a continuous open, short to ground or short to power in the circuit to your transmission's 1-2 shift solenoid. When the code is active, your transmission runs in a fail safe/limp home mode that only lets certain gear ratios function in the transmission.

The solenoid in your application looks like this
and it is located sometimes on the side of the transmission, but my guess is from the looks of it, it might be found inside the transmission, only accessible with the oil pan removed.
The problem might be the solenoid itself, or the wiring going to the solenoid from the computer that controls the transmission, or the computer itself.