Possibly low on coolant. Next most likely is a coolong fan not working. next a thermostat being stuck closed after thata water pump.
get a new temperature sensor.
220.
To install a temperature gauge on a 2003 Chevy Impala, first, locate the engine's coolant temperature sensor, typically found near the thermostat housing. Disconnect the battery, then remove the existing sensor and replace it with the new temperature gauge sensor, ensuring it's securely fitted. Connect the gauge's wiring to the sensor and route the gauge to the dashboard, securing it in place. Finally, reconnect the battery and test the gauge for proper function.
Replace your thermostat had same problem it sets a code but no check engine light
# 1 check point..Your sending unit has worn out. No big deal...Easy to replace..
my o6 chevy impala is lighting up on the dash that the engine is hot but the gauge is saying its cold what is wrong and how can i fix it?
You could have a bad thermostat....mine wasn't moving at all and the fan would come on at start up.Make sure to clear your computer after you change it.
Replace sending unit
get a circuit tester and start looking with the key on
We replaced the temperature gauge in my 1991 Chevy blazer what is the normal operating temp?
The gauges on a 2012 Chevy Impala provide vital information about the vehicle’s operation. The speedometer indicates your current speed, while the tachometer shows engine RPMs. Other gauges, such as the fuel gauge, displays the amount of fuel remaining, and the temperature gauge monitors the engine’s coolant temperature to prevent overheating. Warning lights may also appear to indicate issues such as low oil pressure or battery problems.
It means that the hydraulics which operate your fuel and temperature gauges may be leaking or damaged. One or more of the gauges is out of the normal operating range when engine is running. It could be the oil pressure gauge is reading to low, the temperature gauge is reading to high or the voltmeter is reading to low so, check the gauges.