P0118 Engine Coolant Temperature Circuit High Input

My 1998 WS is acting up again. My check engine light is on and I'm getting this trouble code when having it checked. Can someone give an idea on how to fix this? I'm not getting any heat out of any of the vents as well. It's been very cold outside.
THanks

Hi
I trust you are keeping a close eye on coolant level? Typically no heat equals no/low coolant level. If your coolant level is normal I would guess you had a blockage between the water pump and the heater core, or in the heater core itself. Do you have rear air/heat? If so, you should have a separate heater core in the back. If both are "cold" I have concerns of very low coolant. Continuing on that line of thinking, could your sensor have been damaged due to high temps and no coolant flow?

I would check very carefully. And don't just look at the coolant recovery tank. Pull open the radiator cap as well (cool engine of course) and make sure there really is coolant there.

Have not had to replace one on a Windstar yet. But when you get the High circuit imput. It means sometime the connection needs cleaning or the ECT needs replaced. I have done both on other cars. I first take electrical cleaner and pull the connector be carefull not to break it the heat from the motor can make it brittle over time. They do sale replcacements connectors by the way.. And clean the connector contacts. If that does not work remove the ECT and replace ..you can use teflon tape on the treads so that it wont leak..As for the no heat you may need to flush out the cooling system. I seen that alot on here..

You have 2 temperature sensors......right next to each other....right above the thermostat.....which is where the upper radiator hose goes into the engine.

The sensor that is more toward the front of the vehicle, right over the thermostat, is for the temperature gauge in the instrument cluster......it does nothing else.

The sensor that is more toward the passenger compartment, more over the heater hose outlet, is for the PCM (computer). This is what would trigger the code.

What kind of reading are you getting from the temperature gauge?.....if it is normal, then the problem could be along the lines of the temperature sensor for the PCM or....more likely, the electrical connections between the sensor to the PCM....

If the temperature gauge is reading low.....it is possible that the thermostat is stuck open......or as mentioned, low coolant level.
If the coolant level is low.....you MUST find out where the coolant is going.....
You can take a oil sample and send it in to www.blackstone-labs.com for testing.....and you will find out in several days if the coolant is getting into the oil.
Visit their website for a free sample kit and instructions.

When I replaced the lower intake manifold gaskets.....I found that the "bypass tube" that goes through the lower intake manifold was partially blocked.....in my case, I did not notice anything wrong with the heat......
The bypass tube goes from the output from the water pump, through the lower intake manifold.....and to the spot that the heater "in" hose connects to.
So.....1 thing you could check is carefully grasp the heater hose that comes out of the engine, on the passenger side.....next to the thermostat.....and see if it feels HOT after running the vehicle........HOT would indicate coolant flow.

Also, feel the upper radiator hose to see if it feels hot.....and firm.....Firmness indicating that the cooling system is holding pressure....
Radiator cap would be suspect if the system is not holding pressure.

I have a picture that shows the 2 temperature sensor in my pictures that the link in my signature takes you to......in case this link does not work.
The picture is titled " Coolant Temp. Sensors View With Throttle Body Removed"
http://rides.webshots.com/photo/1350061116011220610mdFuiN

Thanks for all the help, you all. I do know that I drove it to work the other day after I had to put some coolant in the resovoir to the left side of the engine, and it seems the temperature gauge did not move for the longest time. I'd driven it for almost 30 or so miles and it was still down on the cold reading. My rear ac unit has not worked for a long time as well as the front vents have not worked right either. The way the heat was coming into the van before all of this started was through the vents that come up on the dashboard and face the windshield. I recently had replaced the sensor which goes down into the manifold alongside the intake where the top radiator hose connects to.

It sound like you have more than one problem.
If all the air is going to the windshield, then the vaccum controlled selector is not working, the default position for this, if vaccum is lost, is defrost (windshield).
I do not have a rear unit...but I seem to remember reading about some vaccum control for that as well.

The temperature control for the air (up front) is electrical, with a electrical motor that moves the " blend door ".
The blend door control (often the gears between the motor shaft and the blend door) has many posts in this forum, indicating that it is a common fail item as well.

If there is air in the engine cooling system, it will cause all sorts of strange problems.
If the coolant is leaking such that it is getting into the engine oil, it will lead to engine failure due to the bearings not being lubricated......expensive repair to say the least.

I would get it in to a competent shop for a cooling system service.

Wiswind

Thanks for the notice on Blackstone labs. I just bought a 2000 windstar and will be send ing a sample to the lab to see it's condition since I'm ripe for an oil change right now. Have you used them before?

I may have to have the oil checked to see if there is any coolant in it. Can you look at the oil and tell if this is actually happening? I put coolant in the resorvoir on the left side of the engine ( The one with the small water hose going into the top of the radiator) I checked it yesterday and it was empty and the radiator was low as I could not see any water or antifreeze in the radiator. I don't see any leaks around the engine either.
Thanks

Yes, I have used Blackstone Labs, and they have been very good....and very prompt.

The head gaskets are not a high failure item on the post '95 windstar.
However, lower intake manifold gaskets and the front cover gaskets (aka timing cover) are known causes for coolant leakage into the engine oil.
The lower intake manifold gaskets also are known cause for coolant leakage into the cylinders.....it leaks into the air intake, and is drawn into the cylinders.

The coolant will be doing MAJOR damage at levels in the oil far below what you will be able to see by looking at the oil......which is why a testing of the oil is needed.

If you end up doing / having done the repairs for the lower intake manifold gaskets, get the replacements from FORD so that you get the latest improvements.

I just took half of the upper part of the engine apart it seems, I just removed everything to get to the red temperature sensor above the water intake and noticed it only has 1 wire. I also checked the gray sensor which I replaced about 2-3 months ago. At that time I'd also replaced the thermostat. I went ahead and checed the wiring(what a job to just get to the wiring) and there was nothing lose. I put everything back together. I started up the WS and turned the heat on. It only came out of the defrost vents in the upper part of the dasboard. it seems to be blowing hot air and also was coming out pretty strong. Now I've got to figure out how to fix the vents so the air will come out through there as it should. Does anyone know if the radiator cap can cause the heat to not work correctly? Just a question.
Thanks

Radiator cap will not cause the heat to only go to the windshield.
I would look on the passenger side for a small box mounted on the wheel well......with a vaccum line going to it......this is the vaccum resevoir for the air location controls......as set by the knob on the dash that you select Defrost, Heat, Vent, etc.
Start at that box.....and follow the line to the back side of the upper intake manifold.....and make certain that it is connected, and not broken, etc.
Then, follow the vaccum line from the box to the firewall.....making sure that it is intact.
If everything checks out (with the engine off.....when you remove the firewall line from the box.....you should hear a hiss of the reserve vaccum being let go.....).
Then, with the engine running, listen carefully up under the dash for a hissing sound that would indicate a leak.....from a disconnected vaccum line, or damaged vaccum motor, switch, etc.

In other words......you seem to have plenty of heat......so that is working.
Where the air goes....is a separate function...that is controlled / driven by a vaccum line from the engine.
The vaccum comes from the back, passenger side of the upper intake manifold.
It goes to the resevoir box that holds a reserve vaccum to hold the controls in place when the engine is turned off.
From the reserve box, it goes into the passenger compartment to the controls for where the air is to go.

Wiswind,
I want to thank you for all your help. I finally got to the meat of the problem with my WS. As for the CEL going off and coming back on, I finally decided to check my thermostat. I couldn't believe that it could cause my van to not blow any hot air through the vents and my CEL going off one day and three days later coming back on. I pulled the thermostat out and checked in some hot boiling water and it opened up. So I started to put it back in my van. I checked to make sure it was seated right and that I put in the right direction. The light has not come on since. I believe that's fixed. As for the hot/cold air not coming out of the front vents or the lower vents. I checked the vacuum lines coming from the resorvoir you'd mentioned for me to start from. I checked my vacuum lines which are very difficult to get to and followed the vacuum trail into the WS and under the dash and onto the switches that control the AC/Heat. I folowed the black vacuum line and I came to the conclusion that there simply wasn't enough vacuum to activate the actuators under the dash, which allows the flow of air to come either from the winshield vents,front vents or the lower vents. This line had very little vacuum and I thought I heard a small leak. Well that was not it.I noticed that this tube(black line) is t-ed off into another swithch which allows you control the rear unit from the front switch panel. I decided to plug off the in line going to that switch and lo and behold the front unit is working as it should. It's been a long time since it worked as it should and I also traveled to work on many cold days without heat. My rear unit is blowing out hot air, but no cold air. That's my next project with my WS. My wife almost convinced me to sell it, but thanks to folks like yourself whom are willing to give a hand with some great advice have saved me some money. Once again, Thanks.