Engine P0128 Code On 2004 Mustang 3.9l V6....help.

[twdsls2004]

Hi folks,
I am new to the forum here. Driving home my check engine light came on my 2004 Mustang 3.9L V6, but the car ran fine all the way home. No sputtering or hesitation at all. I went out and bought a code scanner to diagnose and the pic attached is the code that came up. I'm hoping you forum folks might be able to give me some guidance as to what needs to be repaired. I read a few websites that discuss cylinder head temp sensor and also engine coolant temp sensor replacement. Does a 2004 V6 have both these sensors, and could they be the culprit(s)? I did replace the thermostat about 2 years ago due to an overheating situation. Thanks everyone, and I look forward to hearing your input.

 

[wmburns]

Does a 2004 V6 have both these sensors, and could they be the culprit(s)?

The 2000 and older V6 Mustangs have engine coolant temperatures (ECT) sensors
The 2001+ V6 Mustangs have a cylinder head temperature (CHT) sensors.

If this were my car the first test would be the find out what the temperature of the motor really is. One of the easiest way is to measure the T-stat housing with a infrared thermometer. If the temperature is too low, then look for a T-stat issue.

If the temperature is above 180 then likely there's an issue with the CHT. Suggestion. Start with an inspection of the wires and electrical connector to the CHT.

 

[twdsls2004]

Thanks so much for the info. I was watching all the dash gauges while I drove home with the check engine light on, and the temperature gauge stayed steady at the normal operating temp. Where on the engine would the CHT be located? I did a good look around under the hood this morning and could not find it at all. I'm guessing Ford hid it nicely and in a difficult place to access/replace?

 

[wmburns]

I don't have a V6 myself. I believe it's on the right side rear under the intake manifold. Look for wires going under the intake manifold near the cylinder heads.

 

[twdsls2004]

OK thanks again. I'll take a look tonight and hopefully locate it. Sounds like it might be "fun" to access/replace if needed.

 

[wmburns]

Here's some information I found online:

http://www.fixya.com/cars/t10240708-coolant_temp

https://www.stangnet.com/mustang-forums/threads/please-help-2001-ford-mustang-v6-3-8l.794543/

http://www.justanswer.com/ford/3i2oo-engine-coolant-temp-sensor-2002-ford-f150.html