So i got the p0128 something code and i replaced the thermostat on my 2003 g35 coupe. I drive for about 200 miles and the light comes back on. I check the code again and its the same code for the thermostat. So my only next idea is that it could be the sensors? has anyone run into this problem yet, so i don't waste money on a sensor if its an easy flush or fix? THANKS!

 

any follow up

 

Possible causes
- Leaking or stuck open thermostat
- Low engine coolant level
- Insufficient warm up time
- Faulty engine coolant temperature sensor
- Engine coolant temperature sensor harness is open or shorted
- Engine coolant temperature sensor circuit poor electrical connection



http://engine-codes.com/p0128_2003_infiniti_g35.html