My thermostat housing was leaking so I replaced it. Now I'm getting the code p2f19 temp sensor signal max and the fan won't shut off. Has anyone run into this? I'm either thinking I didn't hook up something correctly or the unit is faulty. Thank you in advance.

 

There are two sensors that plug into the thermostat.. are they both connected?

 

yes both are connected. The weird thing is when I unplug the sensor that is on the intake, the one where the tube comes out of the valve cover, the code goes to a temp sensor signal min value.

I put in the old temp sensor which was working fine to see if that would change anything but the code is the same.

 

You might have busted or a broken tab on the plugs. Make sure the plug is making contact with the senor side plug. What year and model do you have ?

 

P0118 0x2F19 - Engine Coolant Temperature Circuit High.

As suggested, triple check and make sure sensors are plugged in right. You can use the images from our thermostat DIY to compare with yours to make sure they're in the correct spot. What thermostat did you use? Aftermarket or Genuine/OEM Supplier? There is some resolution in this thread HERE, but not a definitive answer. When you swapped the old sensor on did you clear the codes and then wait to see if the P code came back? Found this thread HERE where the individual had the code due to a thermostat that he just had replaced. They replaced it with a new one under warranty. This one HERE was a wire issue.

 

Part was an aftermarket one. The wires are in the correct locations. Checked multiple times. The thermostat was aftermarket. I did clear codes and it immediately comes back. Maybe the thermostat is bad?

 

2007 mcs

 

If you check over the wires, sensors, and make sure nothing else is leaking or at fault in the system it could be a faulty unit. I have seen this more than a few times, mostly with aftermarket units. However, in that one thread I linked the individual had issues a few times with his Genuine one. Another replaced the unit again and the code still appeared, so that's why you need to make sure everything else looks alright. Did the thermostat come with a warranty?

 

I am pretty sure that everything is hooked up correct. I'm tempted to put the old unit back in to see if the code goes away. That would then definitely either rule out the housing or my incompetence

 

haha you could definitely do that and see if anything changes. Report back with your findings if you do.

 

Ok, just wanted to make sure, you were not one of the years or models with the needed wire harness adapter.

I would guess either the sensor ( but it looks like you tested that ) in the aftermarket one is bad or not working , I would get a new one, sounds like a faulty unit.

 

I appreciate everyone's help. I will update the thread after I replace the unit with the old one.

 

You are welcome. Let me know if you need anything else.

 

You have the temp sensor plug and PCV heater plugs in the correct locations correct?

I have seen them mixed up before which caused issues.

The temp sensor has a green connection, the PCV heater plug is brown and they WILL plug into the wrong sockets.

 

Interesting. I will double check that real quick.

 

NKFRY THANK YOU. That was exactly the problem. Thank you also to ECS and Pelican for their input. They also mentioned the wires. The color coding was exactly what I needed. Looks like the previous owner also had that mistake. The green connector fit into the PCV Heater with no problem making me think that it was in the correct spot. I also saw "brown" and thought it went with the temp sensor since it was brown. Thanks again nkfry.

 

ah, you had them swapped.

Yea, checking the wire connection, i thought you already had them matched up correctly. I marked mine with tape when i took my thermostat housing out, since I knew the harness would be moved.

Glad it worked, good thinking nkfry .

 

Glad it was simple, I've only run into it once, but it was enough to cause a constant CEL and limp mode, the customer unfortunately had to buy another new thermostat though as the PCV heater shorted the temp sensor.