HVAC Issue

[ryanyoung0]

My 2021 Sport S has an HVAC problem where the driver side and the rear vents seem to blow the correct temperature but the passenger side blows hotter. At max AC and max heat they all blow the same temperature. In between it seems like the passenger side is 10 to 15 degrees warmer. I took it to the dealer and they did a heater core flush. This did not work and they quoted me $2800 to replace the heater core and box. To me it seems more like a blend door issue but I don't have much idea about how to prove that. If anyone has any ideas for debugging the problem myself or if I am crazy and I should just pay up please let me know!

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[Thunderspud]

I have noticed something similar now that it's starting to get into warmer weather. Possibly related.....I also sometimes hear a clicking noise behind the dash that I have yet to be able to trace. I say "possibly" because I have no proof that the two are related. The noise happens regardless of the settings the climate control is using. My Grand Cherokee will activate the A/C (with no dash light) and move the blend doors as it sees fit to defrost the windshield. I assume this truck does the same.

I had planned on trying to tear into it myself this weekend, but until the doors go back on it's more out of site/out of mind for me. I'll follow up if I find anything though. Maybe someone else has a different idea.

 

[ShadowsPapa]

The dealer is totally lost if they thought a heater core flush would resolve anything other than a plain lack of heat inside due to a plugged or restricted core - which is extremely unlikely in a vehicle only 4-5 years old!

The 2020 and 2021 have a TSB (technical service bulletin) related to similar HVAC issues.

Don't let that dealer replace a bunch of parts like that!

Have they checked for any DTCs (codes indicating a problem that won't necessarily trigger the check engine light) ?

There's a whole procedure for them to follow to check operation of these things - a multiple page process. They need to actually follow that and stop throwing things at it to see what works.

 

[ryanyoung0]

The dealer is totally lost if they thought a heater core flush would resolve anything other than a plain lack of heat inside due to a plugged or restricted core - which is extremely unlikely in a vehicle only 4-5 years old!

The 2020 and 2021 have a TSB (technical service bulletin) related to similar HVAC issues.

Don't let that dealer replace a bunch of parts like that!

Have they checked for any DTCs (codes indicating a problem that won't necessarily trigger the check engine light) ?

There's a whole procedure for them to follow to check operation of these things - a multiple page process. They need to actually follow that and stop throwing things at it to see what works.

Blend door is the problem (not the actuator) going to have to have the dealer resolve the hvac box I guess…

 

[sharpsicle]

Blend door is the problem (not the actuator) going to have to have the dealer resolve the hvac box I guess…

What led you to that conclusion? Was all the testing @ShadowsPapa mentioned performed?

 

[ryanyoung0]

Yeah I got an OBD reader with JScan recalibrated the actuator then got the report code that the passenger side blend door is stuck. Interesting after the calibration I get no heat out of the passenger side now

 

[ShadowsPapa]

Yeah I got an OBD reader with JScan recalibrated the actuator then got the report code that the passenger side blend door is stuck. Interesting after the calibration I get no heat out of the passenger side now

Stuck could mean something is in there and it simply needs to be accessed and fixed, or something is broken.
One means only labor to unit k it, the other means parts and labor.

Sounds like it actually did move....to closed.

 

[ryanyoung0]

I actually tried replacing the aviator when trying to figure out what the problem was. And during that I moved the gear with my hand. It was pretty tough to move. After moving it once or twice then it becomes easier…. I don’t know what would cause that

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