I have a 2001 Camry LE that I just picked up, and there was a code for 'Coolant Temperature Below Thermostat Regulating Temperature' - I have since replaced the 2 sensors on the water outlet, new thermostat, and flushed + refilled the system with Asian pink coolant, but within a day the code comes back - Is there another sensor that I am missing that would cause this code? Heat works perfectly, and I can tell the water pump is working due to seeing the coolant moving through the radiator - Coolant systems are supposed to be EASY!!!

P.S. Replacement parts were all purchased from my local Toyota stealership

 

Was the code P0125? If so relates to the A/F sensor.

 

No, code is P0128 (coolant temperature is below the thermostat regulating temperature)

 

Are the coolant fans stuck on?

Do you have a scanner that can read IAT and ECT temps? Check if temps are close to same when engine is cold. Check ECT temp when engine is warm. Should be something like 177F to 205F.

 

Fans are running as they should from what I can see - The scanner I have can only read/clear codes, doesn't have any options for temps - One other thing I forgot about is when I first start the car in the morning the RPMs jump up to 2k immediately, then as the temp goes up the RPMs drop to normal, seems to be much higher revs initially than my other cars, not sure if it is related.

 

Do you have an ohm meter?

See private message.

 

No ohm meter, either - I have a buddy coming by with his scanner, which will read the coolant temp, so I should know in about an hour whether the temp is within range

 

Coolant temp averages 182F over 20 minutes, both idling, and driving

 

Read the code info sent via private message.

Computer is looking for coolant temp over 167F within a set time after engine start. Guessing this is 900 seconds more or less. One criteria for the test to start is the air intake temp must be in a set range. Check intake air temp to determine if its where it should be as in close to ambient air temp.

Perhaps the test starts too soon as when coolant is not warmed up.

The T-stat is 82C.