When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
The heater are not working.
The Control Panel fault code is 14 which is water temp input malfunction instrument cluster output.
Refer to PDU.
How is this repaired?
Is it a wire fault that is repairable? Dry connectors?
And where is it?
To troubleshoot I would like you to do a couple of things:
First manually raise the control panel temperature setting by pushing the red arrow until it goes to max heat. Now do you get heat? If so then the heater matrix is functioning.
Second press the outside temperature button and observe the outside temp reading. Is it close to accurate?
Most likely the outside temp is a lot higher than actual temperature. If it is, then the problem is the ambient air temp sensor. It is located under the bumper cover on the front passenger side and easily changed.
My heat would not engage in auto because the ambient sensor said the outside air was 132 degrees Fahrenheit.
To clarify, it is the cabin heater.
Manually raising the temp button to max does not get any heat.
Outside temp button works and is accurate.
A/C works. The Control Panel fault code 14, which is " water temp input malfunction instrument cluster output." I interpret to refer to a water temp signal needed from the instrument cluster to the heater controls to be able to work. Instrument temp gauge works and the engine temp sensor is OK and reads to an elm reader. Mark
Have you tried to reset the A/C system in case this error was a one-time occurrence? If you don't mind resetting your windows (and possibly re-entering your radio code), have you tried the "hard reset" procedure with the battery cables?
On the face of it, with this input faulty, the system might keep the water valve closed, and not let any warm water in the core. You can bypass this by unplugging the water valve because it defaults open. It is on the firewall, a bit low, and by the nest of hoses to the heater core. You have to follow the wires as there are 2 plugs (heater pump and valve). If you have tons of heat after unplugging the valve, then you can research that sensor error.
Separately, try and see if you can locate the relay for the heater pump, and short the supply pins to force it to run. With the engine off, you can then hear it much better. A mechanics stethoscope can also tell you if it is running. These pumps are known to wear out (carbon brushes), but can be fixed cheaply. Hard to reach, though. If the pump does not run, check the resistance at the same relay terminals for open circuit. I believe the pump runs constantly as long as the A/C system is turned on, there is no relationship with demand for heat. Last, these pumps have a magnetic coupling with the impeller, so having the pump run does not necessarily mean the impeller is spinning.
Once you figure out the diagram, you can also test if heat is moving around, either with your hand or a laser thermometer on the various hoses.
FWIW, I went down chasing heat issues last winter and the fix ended up being a core cleanup with fresh water and radiator cleaner (and no, nothing dramatic came out of the core). Performing this simple cheap procedure DRAMATICALLY improved the heater performance (I had some lukewarm air in maybe half a mile after this procedure, hardly any before that in 10 miles). Problem with this system is that it is not completely obvious to identify problems with either the pump or the valve, and each one is pretty expensive and hard to reach.
If engine cooling is working properly and it's only a heater issue, I'm with fmertz on heater valve or pump.
Not relevant to resolving your issue but a useful routine to follow - something I was advised to do many years ago by an experienced tech was to cycle the AC from maximum hot through maximum cold once a month. This activates all electrical and mechanical controls through their range. Leaving the AC on a fixed temperature for long periods frequently leads to sticking flaps and valves when you eventually do want to vary the cabin temperature or air distribution.
Heaters not working
