99 escort - p0125 code, engine temperature cold

Hi all,

The temperature guage on my 99 escort does not move up from Cold. In fact the guage is past the C indicator and stays there. Even when the weather is not that cold sometimes the car has trouble starting. The air conditioning tends to be not as warm as i would hope, and doesnt warm up as fast as i would expect (not sure if this is related) Lastly, only on long highway trips, we get a p0125 code warning (via service engine (http://www.fordforum.com/m_22430/mpage_1/key_/tm.htm#) soon). The definition for this code is:

"the engine (http://www.obd-codes.com/trouble_codes/generic/p0125-insufficient-coolant-temperature-for-closed-loop-fuel-control.php#) coolant (http://www.fordforum.com/m_22430/mpage_1/key_/tm.htm#) temperature (ECT) sensor indicates that the engine has not reached the required temperature level to enter closed-loop operation within a specified amount of time after starting the engine."

I have cleared this error maybe 3 or 4 times now. To me all these symptons seem related. Like i said this code only comes up when we do a drive which is 2 hours long on the highway, general in town driving (http://www.fordforum.com/m_22430/mpage_1/key_/tm.htm#) does not set this off.

Is there anything anyone can suggest here? I am not all that familar with escorts but just wondering if there were any quick fixes (and appropriate instructions) that may fix this before i send it to the professionals. I did check the coolant level the first time it happened and it seemed to be ok, i could check this again though.

Thanks for any help !

Try changing the thermostat. Sometimes they will stick open and not allow the engine to reach the required temperature. Then make sure that the coolant level is normal. I suspect this will cure the problem. If not replace the temperature sensor and see what happens.

Try changing the thermostat. Sometimes they will stick open and not allow the engine to reach the required temperature. Then make sure that the coolant level is normal. I suspect this will cure the problem. If not replace the temperature sensor and see what happens.

thanks for the prompt reply !!! The only thing im comfortable doing from the above is checking the coolant temp. When i looked at it there was 2 lines, i think one said COOL and one said HOT or similar. It was at the bottom line which i assumed it should be at when the car is just sitting there and not running. I will be checking this level again to make sure it is still ok.

As far as replacing the thermostat, is this something i can do easily myself ? If so what part do i need to purchase (how much?) does it need to be from a ford dealer ? Where and how do i replace this?

Same deal for the temperature sensor, is this expensive for me to buy, and will i be able to replace this myself?

Once again thanks for your reply, and i appreciate your continued help !

You didn't say which model you have but the process is the same. Drain the radiator and follow the top radiator hose to the engine block. Once you find the connection then the thermostat is located inside the housing where the hose connects. On the 2.0 vin P engine the coil and the bracket that holds it in place will need to be removed. After removing that remove the thermostat housing. Remove the old thermostat and install the new one. Reinstall the housing, use a new gasket and the remaining parts. Refill the radiator and start the car. Allow to warm up and refill the radiator as needed. Replace the radiator cap and you should be good to go.

The thermostat can be purchased at any autoparts store and range in price from $7 to $12 dollars. The temp sensor may be a dealer only part but I would check the autoparts store. You may want to spend a few dollars on a manual for your car as it will show you the procedure. I like Chiltons more than Haynes but either is acceptable. This is a true DIY job and should only take an hour or so to complete and it only requires simple hand tools.

Good Luck!

Save yourself some trouble and replace the sensor first. Even if the thermostat was closed the sensor would read the temp since it is inline with the heater core and not the engine.

I am not certain about the ECT location on a 99, but on my 94 it is easily reached under the intake hose and is in a hose that goes back to the firewall at the heater core. There are two sensors side by side... one is the ECT for the gauge and the other is the sensor for the computer and fan.

I suppose another possibility is that your heater core is plugged and not permitting flow through the hose leading to the sensor... in which case the sensor is probably still bad.

You mention that the heater is slow to warm, so that is certainly a possibility. If you can identify the heater hoses going into and out of the heater core at the firewall you can feel them when the engine is running to determine if water is running through them.

If you decide the heater is taking way too long and aren't making any progress with the problem, you might want to get into a shop and tell them you suspect the core is plugged up and ask them to flush the system out. This may work and may not. Heater cores can be very expensive to replace if it comes down to that.

However... if it is just a sensor after all, it is just a few dollars and takes less than 5 minutes to do.

I suspect the thermostat.