Engine light on, scan code said thermostat

Did you burp the air out of the cooling system?

TEMPERATURE GAUGE IS MORE LIKELY BROKEN.

It is possible that your thermostat is stuck open. Normally, the thermostat remains closed when starting cold, confining coolant to the engine block and cylinder head until it heats up. Once the coolant in the block is warm (usually within 10 minutes), the thermostat begins to open and let coolant flow into the radiator to cool it down some. A properly operating thermostat will continue to cycle until the coolant reaches the operating temperature of the thermostat--usually around 180 deg F. Then the thermostat will continue to adjust its opening to maintain that temp.

Thermostats can get stuck in both closed and open positions. When stuck closed, the engine will quickly overheat. When stuck open, the engine will take forever to warm up--especially in cold weather because the coolant is continually pushed into the radiator and cooled off before it ever has a chance to get warm. Changing the inexpensive thermostat may help correct your condition.

Yes that is what the code means. GM usually uses two, one that makes the gauge work and one that tells the ECM what the engine temp. is. You need the one for the computer.

Yes, change out the thermostat. It's probably stuck all the way open because in Arizona it rarely gets cold enough for it to need to close down allowing the engine to warm up. It's easy to do. Try this link for instructions.

If the thermostat is stuck open, the engine temperature will drop and set a fault code indicating that the engine is not reaching operating temperature. This will cause your check engine light to come on. Have someone scan your engine computer. Most large parts chains will scan for codes at no cost to you. If there is a "Thermostat" or "Engine temp low in closed loop" or a similar code indicating low engine temperature, replace the thermostat.

I had the same problem with my car. I cleaned the throttle body and when i installed everything back, the car would throw 2 OBD codes: P0120 at start up and P0507 when it stalled at a red light. Took it to the dealership and they had to install a new throttle body because the throttle position sensor is internal. Cost = $718.00 out the door. Part is about $480 and labor is 1.8 hours at $99.00/hr (bunch of ****). There is only a 12 month/12,000 mile warranty for work from the dealer so I would recommend doing the work yourself if possible. There is only 2 bolts on top, 2 nuts on bottom, 1 electrical connection, and 1 hose clamp.

if you live near an AUTOZONE parts store or PEP BOYS they will scan for free

Did u have engine codes scanned? If not, have it done, as it may indicate the problem. Let me know. (most parts stores will scan for codes free) .

check evap vent solenoid alot stick on these cars.