Hello to all!
I recently bought a 2003 Toyota Camry 4cyl with automatic transmission. A few days ago the check engine light came on, so I decided to use the scanner tool, the error code is P0125. I read is related to the ECT Sensor. I replaced the sensor and cleaned the connector, I made a reset to get rid of the check engine light, however it came back after driving it for a couple of miles. The water temperature looks normal to me measuring half of the gauge. Something I noticed is the fan starts working but only blows air for no more that 15-20 seconds and then stops. I really don't think it's overheating, but I'm not sure what to do next. Any help will greatly appreciated.

 

The ETC sensor measures coolant temperature and then outputs a signal based on the temp. The P0125 code sets if the sensor does not output a specified signal after a specified period of time.

The issue could be the sensor or the coolant temp. In this case of the coolant temp the thermostat or a problem with the coolant system causing the coolant to not be at the proper temperature at the specified time. The computer does not know if the issue is the coolant temp or ETC sensor.

Check coolant system and thermostat for proper operation.

The radiator fans turns on and off? Another coolant temp sensor on/off switch operates the fans. The ETC just sends a signal to the cars computer as to what the coolant temp is.

 

Thanks for replying,

The radiator fans turn on and off for a short period of time with no A/C. With A/C they stay on as long the A/C is working. I have found no evidence of coolant leaks so far, so I'm now guessing it could be the thermostat. Is it true the O2 sensor could cause this issue?

Thanks again.

 

Stated that late model 90's Camry could have issues with O2 sensor heater circuit causing this. The 2003 is a later generation of Camry.

 

Oh Ok, and what about AF sensor? Could that cause this error code or not? Gas mileage has been terrible since the issue started.

 

MPG could have dropped because the coolant temp is not being adjusted correctly.

If the computer does not get out of what is called open loop operation, the MPG will drop. The computer changes to closed loop when the coolant temp reaches a set point.

A bad A/F sensor can cause poor MPG. The sensor has its own trouble codes. A bad sensor can also cause the computer not to get out of open loop operation.

Check voltage between the gray/yellow and brown wire of sensor with sensor plugged in, engine at idle with coolant warmed up. Voltage should be 0.2 - 1.0v.