'13 RT front HVAC only lost Temp. control

[5rebel9]

Well, with the 5 DJ's I've had this is a new problem to encounter. Car has ATC but when TEMP is set to full high, I get full heat out any set position. When I lower the TEMP even one degree on the infotainment screen the temp goes to full cold even though the display shows desired TEMP setting.

 I suspect the HVAC module in the center stack behind the infotainment screen and when the sun comes up will hook up my alphaobd program and see if I can find the problem using that. 

In the meantime if anyone has suggestions, I'm open to read/try them. 

[John/Horace]

Yeah scanning for codes is the best start. My wild guess would be cabin air temp sensor( 55111178AD) or heater core temp (long wire style probe harness) sensor, neither are super pricy, although access might be crappy. You have parts car you can pull from still, so if ATC that would help. 

 

Did this journey have the heater core swapped out ? If so probe could have been disturbed.

 

 

[5rebel9]

Code B11ca comes up as only fault. 

Took out glove box and watched movement of the pass. actuator. It moves freely, but in large movements with steady hold on control buttons hot or cold(not smooth and steady). NO clicking or sticking.@John/Horace this has the original heater core and NO under dash work has been done on it. MY understanding of the earlier models with ATC that only fan speed was affected by ATC, as desired temp is set by the operator (could I be wrong?).

[5rebel9]

Well it is an actuator for the pass. side heat control, still functional but slow in matching output when in sync. mode.

 I went to my friend yesterday to pull one and he said he needed 3 also, if I would pull them I could have the fourth. Same actuators in the vans, and he has more of them and easier to access the actuators. I pulled 3 and was getting sore, so left the fourth (mine) for another day. Since I know what is going on now and is now my main ride since the wife took over the '17. my mind is more at ease about the situation. I'll rest up a bit and then pull the final one and change out the actuator on another day.

[2late4u]

LOL... getting to them is like being a  acrobat ,,,, video would be fun to watch

[5rebel9]

2 hours ago, 2late4u said:

LOL... getting to them is like being a  acrobat ,,,, video would be fun to watch

I agree with you   

BUT I am NO VIDEOGRAPHER to take and post things.....LOL    

[John/Horace]

If you are not using a scanning tool for sensor change, need to access the power fuse in kick panel for the actuator. As you know the cabin venting timer leaves the blender open for a few about 2 mins after shutdown. Prevents mold smell, most newer cars do this.

 

If you have glove box down and you look at sensor, you can see the timer in operation. I have switched to 1/4" square head screws on these sensors. Philps shorty toohard to work with.

[5rebel9]

12 hours ago, John/Horace said:

If you are not using a scanning tool for sensor change, need to access the power fuse in kick panel for the actuator. As you know the cabin venting timer leaves the blender open for a few about 2 mins after shutdown. Prevents mold smell, most newer cars do this.

 

If you have glove box down and you look at sensor, you can see the timer in operation. I have switched to 1/4" square head screws on these sensors. Philps shorty toohard to work with.

Here is the latest.....

The alphaOBD has an all actuators test and this is where I picked up the B11ca code for pass. side temp actuator. BUT it said also that the problem was intermittent. Another related control problem I found was that the A/C button on the main control panel was not working unless recirc. was also pressed, and once on would not shut off unless done on the 8.4" screen or vehicle turned off(on restart A/C was on). Yesterday I got a control panel from my friend and all seems to be working correctly now, but I have not yet driven the car to check for good temp. adjust action. I'm doing that test drive this morning.

    On a side note.... it was NOT the cabin air temp sensor in the lower dash panel. I tried that and found the used one I got was bad and it set a code for that on my alphaOBD program, so the original cabin temp sensor was put back in.

 

 and yes the phillips screws are a pain to work with, the vans use torx screws and are quite a bit easier to work with. I had to replace the recirc door actuator on my former '14 and used the torx screws when I replaced it

[5rebel9]

On 10/14/2026 at 7:22 AM, 5rebel9 said:

Here is the latest.....

The alphaOBD has an all actuators test and this is where I picked up the B11ca code for pass. side temp actuator. BUT it said also that the problem was intermittent. Another related control problem I found was that the A/C button on the main control panel was not working unless recirc. was also pressed, and once on would not shut off unless done on the 8.4" screen or vehicle turned off(on restart A/C was on). Yesterday I got a control panel from my friend and all seems to be working correctly now, but I have not yet driven the car to check for good temp. adjust action. I'm doing that test drive this morning.

    On a side note.... it was NOT the cabin air temp sensor in the lower dash panel. I tried that and found the used one I got was bad and it set a code for that on my alphaOBD program, so the original cabin temp sensor was put back in.

 

 and yes the phillips screws are a pain to work with, the vans use torx screws and are quite a bit easier to work with. I had to replace the recirc door actuator on my former '14 and used the torx screws when I replaced it

After a COLD outside temp test drive

  All HVAC functions are working properly with the replacement panel and knowing that the pass. side heat actuator is going bad, there is just a 6* temp difference according to screen temp to hand feel of actual temp. full high and full low are FINE.

After handling 16 face chord of firewood(and 4 more to come) this last week, I'm too sore to try and replace the actuator any time this next week! IF decent weather prevails into early Nov. I MAY "tackle" the chore!

[Robert Miller]

Good to hear the replacement panel cleared the A/C button and startup behavior. The 6* spread between screen temp and hand feel makes sense if the passenger actuator is only partially sweeping, since the extremes still hit but the mid-range blends drift. Intermittent B11CA fits a failing actuator rather than the cabin sensor. Rest up before tackling that job; those Philips screws are worth swapping for something easier while you're in there. Let us know if the temp split widens once you get the actuator replaced.

[5rebel9]

14 hours ago, Robert Miller said:

Good to hear the replacement panel cleared the A/C button and startup behavior. The 6* spread between screen temp and hand feel makes sense if the passenger actuator is only partially sweeping, since the extremes still hit but the mid-range blends drift. Intermittent B11CA fits a failing actuator rather than the cabin sensor. Rest up before tackling that job; those Philips screws are worth swapping for something easier while you're in there. Let us know if the temp split widens once you get the actuator replaced.

Learn Physics

 

Having 3 on the road right now and having sold off 2 others, I've only had ONE to have an actuator go bad until now. And that one was for the easier to access recirculation door actuator.

You're correct that I need to rest up very well for the pass. side actuator....problem is that life's chores never seem to slow down to allow "resting up"!