Just had the infamous thermostat housing leak fixed and was confused about which sensor/sender to get so I called a Ford dealership and they gave me what I think are the wrong part numbers. The sender had threads so I knew it was absolutely the wrong part. The sensor however looked correct. I sent my truck to the local mechanic to get it all put together (I already did it once before 6 years ago with cheap parts and wanted it done right this time, hence the Motorcraft parts) and got it sent back with code P0117.

Before a cold start the sensor reads the coolant as 180F, takes about five seconds to turn over and drives poorly at anything below highway speeds. At full operating temp it reads 280F. This is obviously incorrect as the sender reads fine and the coolant is clearly at ambient temperature when it's been sitting. When I unplug the sensor wire it reads -40, so I don't think the PCM or the wire are shorting out.

Is this the wrong sensor or is it faulty? Confused as I used what Ford says were the correct parts.

Thank you

 

I went to Tascaparts.com and found the sensor p/n 9U2Z-12A648-A. It's ~$35.
Please list the year, trim level, engine and mileage of your vehicle in posts as not everyone will search a profile as I did.
Is the sender which "reads fine" in the second paragraph your old one?

 

Oh shoot it's been so long since I've been on the forum (apparently I'm really good at fixing things when I do it myself, I should stick to that) I forgot what I'm doing, I apologize :D 2002 XLT with 4.0L SOHC

Looks like that part for Motorcraft is DY1145. And even with the p/n there are multiple different designs to pick from. Very confusing.

The current sender is one the mechanic bought and installed, because they saw that Ford had given me the wrong part (it was threaded and clearly didn't fit). The other part Ford told me to get which was also wrong, the sensor, is currently in the vehicle and I believe that is technically supposed to be a sender, thus the bad readings.

At this point I think I've got it figured out and will probably fix it myself because Ford really screwed me over here and I feel like an idiot for not trusting my local mechanic. But hopefully this will educate people attempting this job in the future.

 

This How-To has the part numbers if you have TWO temp units: https://howtoreplacefordthermostathousing.com/

I think 2004 and up just had the one sensor, no sender as the cluster was digital so computer sent temp info to the gauge

You can get metal thermostat housings for the 4.0l SOHC now, to avoid future issues

 

My '05 has the pair (sender/sensor). Would the FX4 Off-Road package have anything to do with that?

 

It seems exact year Ford switched from 2 ECTs to 1 ECT on V6~4.0L~SOHC ThermoStat Housings
varied with body model: Explorer\LandRover\MazdaB\Mustang\Ranger\Sport\Spo rtTrac\...
Best avoid cheap\NonOEM aftermarket replacements that are known to fail often.

OEM part numbers for the 2 ECTs & the MountingClips on my 2001 V6~4.0L~SOHC; click blue links for vendors.
Sensor FordMotorCraft# 3L8z12a648ba\dy1004
* Gray2pin~PowerControlModul, @32f0c Measures ~104kOhm
Sensor FordMotorCraft# 3f1z10884aa\ts390
* Brown2pin~ClusterTempGauge, @32f0c Measures ~12kOhm
2eaSensorClip Ford# w706800s303

Also best to swap junk Plastic ThermoStat Housing for an Aluminum version; click here for more info.

 

OOPS, yes it looks like 2007 is when Ford switched Rangers over to just the 1 ECT sensor, that was also the year they changed to the 3 connector PCM(computer)
2006 cluster diagram shows temp sender being used, in 2007 its gone