Auto climate control not as effective in the cold

se7en

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Thanks for the update. :(





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digitalbliss

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So just an update because somebody asked...

I tested mine again this morning after the software flash. Same problem as before. Ambient temp = 28 degrees, auto climate control set to 72 degrees, actual temperature in the Jeep 59 degrees.

That's a 13 degree spread between what it's set to and what it actually was in the vehicle. I saw this before the software flash also...sometimes it would be as much as a 16 degree spread.

Sigh...

It didn't cost me anything so it was worth a shot.
I have mine scheduled to go in Friday. This doesn't give me much hope though. I have a theory that the sensors are poorly placed to a good heat balance. I wondering doing the same test, but placing your indoor thermometer by the foot well/knee area, would yield a different result.
 

Rhinebeck01

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So just an update because somebody asked...

I tested mine again this morning after the software flash. Same problem as before. Ambient temp = 28 degrees, auto climate control set to 72 degrees, actual temperature in the Jeep 59 degrees.

That's a 13 degree spread between what it's set to and what it actually was in the vehicle. I saw this before the software flash also...sometimes it would be as much as a 16 degree spread.

Sigh...

It didn't cost me anything so it was worth a shot.
Thanks for posting the update. Spoke with dealer the other day, when you first posted / posted the 08-042-18 number.

The Tech there told me it applied to JL's just prior to my build date but he would still do the flash for me. I was to go in tomorrow at 2pm.

After you posted your update today, I called the Tech and told him false alarm, and to cancel the appt. 8-)

Anyway, thanks much @WXman for following through with the update you promised.

I might add that the Tech at the dealership looks forward to the info I bring to him from the forum.

Last tidbit, I brought him .... the TSB18-041-18 Rev. B (Fix Hi-Rev) that stopped the JL from roaring when the AC was on Max, on hot days, made him a believer in the notion that often guys/gals that visit the forum(s) can bring them tidbits that help them do their job/help make their patrons happy. They had lots of complaints about the roaring, this Summer.

Anyway, with open arms lets say, they gladly try fixes and such I ask them to try.
.

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Ntegtmeyer

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Thanks for posting the update. Spoke with dealer the other day, when you first posted / posted the 08-042-18 number.

The Tech there told me it applied to JL's just prior to my build date but he would still do the flash for me. I was to go in tomorrow at 2pm.

After you posted your update today, I called the Tech and told him false alarm, and to cancel the appt. 8-)

Anyway, thanks much @WXman for following through with the update you promised.

I might add that the Tech at the dealership looks forward to the info I bring to him from the forum.

Last tidbit, I brought him .... the TSB18-041-18 Rev. B (Fix Hi-Rev) that stopped the JL from roaring when the AC was on Max, on hot days, made him a believer in the notion that often guys/gals that visit the forum(s) can bring them tidbits that help them do their job/help make their patrons happy. They had lots of complaints about the roaring, this Summer.

Anyway, with open arms lets say, they gladly try fixes and such I ask them to try.
.

.
THIS!!!! As a service advisor at a Jeep dealer, I can 100% agree. I have customers sometimes that come in with various small complaints. Most of the time we can’t replicate it at the dealer, so automatically they assume we’re lying or being lazy, when really we just have no idea where to start. So I often say take videos or pictures of what’s happening so we can try to pin point where to diagnose. Being active on the forums and everything else, I’m fairly up to date with stuff when it comes to the JL and WK2s which is very beneficial to me so I can help my customer better.
 

nerubi

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No Bill, what I want, is the upper half of the cab to be close to the temp I have set it to. Unfortunately, it seems that when set to heat, it only blows to the foot well, warming the lower half of the vehicle and then shuts off significantly while the upper half is still 15 degrees (or more) colder than the temp setting.

The sensors must be located near the lower section of the vehicle instead of near chest high. So even though your feet are comfortable, your torso, arms, hands, face, head, etc... Are still quite cold. And since auto never seems to kick warm air through the vents (only cool air) the rear vents and passengers never get warm air to the back.

The programming really needs to blend vent and foot vents for heat. With a drafty, poorly insulated top, the Jeep seems to get cold drafts in the upper section, usually flowing from the rear. Heat from the foot Wells do almost nothing combat this and with the sensors being so low, they don't sense the colder air anyway and therefore keep the heat and fan speed set too low.
I haven't looked for the temperature sensor on the JL yet but if I remember right it is low on the dash on the JK. Looking at the manual it would appear in auto heat mode it only does floor or floor and defrost. It is hard for the auto function to handle upper temperature versus floor when the sun can be making your upper body hot while your feet are cold. Or back seat the same as the front with only one thermostat. I just checked mine - in auto when calling for heat the floor vents only had air, nothing in back. When in manual floor only selected nothing from back vents (engineers must have determined the floor vents in front will push air under seats to back). In panel or bi-panel mode warm air in front and back. A more detailed explanation of the climate control system in the manual would be helpful.
 
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digitalbliss

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I haven't looked for the temperature sensor on the JL yet but if I remember right it is low on the dash on the JK. Looking at the manual it would appear in auto heat mode it only does floor or floor and defrost. It is hard for the auto function to handle upper temperature versus floor when the sun can be making your upper body hot while your feet are cold. Or back seat the same as the front with only one thermostat. I just checked mine - in auto when calling for heat the floor vents only had air, nothing in back. When in manual floor only selected nothing from back vents (engineers must have determined the floor vents in front will push air under seats to back). In panel or bi-panel mode warm air in front and back. A more detailed explanation of the climate control system in the manual would be helpful.
I'm going to guess that pretty much everything you wrote here is correct. Although the decision to make the auto (in heat mode) only function to the floor or defrost seems wonky to me. Pretty much everyother vehicle (that I can remember) that I have operated with an auto HVAC system, will blow warm air though the vents as well.

As a side note, I have found my best method of operation for comfort in cold weather. When leaving in the morning I just leave it on auto, parking in my garage keeps it warm enough that auto does fine and sometimes warms it more than I would like (ironic huh?). But coming home, when the Jeep has been left out in the cold all day, it's another story. Selecting auto will warm the foot well area sufficiently but not the other 80% of the Jeep. If I manually select the bidirectional foot/vent and set the temp and fan speed, it does much better until the foot well area snses the tems and then reduces the temperature of the air flowing through the vents and allowing anaimbalance of cold air unless I start cranking the temp up to 78-80 degrees.

However! If I START with the dash vents only, and set the temp and fan speed, it will quickly begin to warm the cab and the rear. Unlike the bidirectional setting, it will keep hot air blowing because (I think) the warm temps are not making it to the low positioned sensors. Once the upper section is nice and comfy, I set it back to auto,which then blows at my feet, bring the temps there up, hitting the sensor, and backing down the temp and fan speed. From there it seems to do well. LOL
 

nerubi

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I'm going to guess that pretty much everything you wrote here is correct. Although the decision to make the auto (in heat mode) only function to the floor or defrost seems wonky to me. Pretty much everyother vehicle (that I can remember) that I have operated with an auto HVAC system, will blow warm air though the vents as well.

As a side note, I have found my best method of operation for comfort in cold weather. When leaving in the morning I just leave it on auto, parking in my garage keeps it warm enough that auto does fine and sometimes warms it more than I would like (ironic huh?). But coming home, when the Jeep has been left out in the cold all day, it's another story. Selecting auto will warm the foot well area sufficiently but not the other 80% of the Jeep. If I manually select the bidirectional foot/vent and set the temp and fan speed, it does much better until the foot well area snses the tems and then reduces the temperature of the air flowing through the vents and allowing anaimbalance of cold air unless I start cranking the temp up to 78-80 degrees.

However! If I START with the dash vents only, and set the temp and fan speed, it will quickly begin to warm the cab and the rear. Unlike the bidirectional setting, it will keep hot air blowing because (I think) the warm temps are not making it to the low positioned sensors. Once the upper section is nice and comfy, I set it back to auto,which then blows at my feet, bring the temps there up, hitting the sensor, and backing down the temp and fan speed. From there it seems to do well. LOL
Exactly what I had to do on my Yugo with auto climate option. :)
 
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digitalbliss

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I had the TSB mentioned above applied today, we will see how it does. I'll give an update after a few days with my thoughts.
20190125_140344.jpg
 

HoosierJL

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Jus a note that the cabin temperature sensor is on the panel below the steering wheel, just like in the JK. On my JK, I had to put insulation around the back side of that panel around the sensor because the plastic panel was warm from the heat blowing on it and that heat reached the sensor even though the sensor is pulling in air from waist high that was cooler. the insulation fix in my JK did a world of good and made the auto climate control work well in all seasons.

Just today I insulated the sensor in my JL, so I don't know if it will improve heating performance yet. I picked up a 3/4" pipe insulating elbow from Lowe's for $3 and cut it to fit, about 1" long tapered to 2" long. Pull the bottom of the panel below the steering wheel straight toward the rear of the Jeep to remove it. There are 6 metal clips in there holding it. You can put the pipe insulation around the sensor and push the panel back on.

I did a quick job on the JL but I can see the insulation is there when looking through the little vent in the panel so I hope it will work.
 

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@HoosierJL

Having the Tazer JL means I have that plastic below the steering column off often.

I'm not familiar with the sensor you speak of.

Next time you have the panel off, could you take a pic of the sensor and your mod and post it here. Thanks!

Trivia: That particular JL panel, under the steering column, costs $25 and is a Lower Cover - Mopar (6AA94TX7AA)
lll.JPG
 
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digitalbliss

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My first impressions of the TSB is that it has helped quite a bit. This coming week is going to be about as cold as we've had this year, so it'll be a good chance to test it out.

It seems that after the TSB, the fan speed stays at a higher speed, longer and the temperature of the air from the vents is higher. It also seems that maybe the foot well/defrost split is more evenly split, giving more warm air to the cab via the defrost.
 

nerubi

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My first impressions of the TSB is that it has helped quite a bit. This coming week is going to be about as cold as we've had this year, so it'll be a good chance to test it out.

It seems that after the TSB, the fan speed stays at a higher speed, longer and the temperature of the air from the vents is higher. It also seems that maybe the foot well/defrost split is more evenly split, giving more warm air to the cab via the defrost.
North Alabama gets cold? We are going to have -40° wind chill and highs some days around 10° this next week. When I worked in KC we had staff from Dallas move there but many moved back after a year because they couldn't stand what they said was Alaska weather.
In the 50s and 60s weren't heaters optional in cars sent to southern states?
 
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digitalbliss

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North Alabama gets cold? We are going to have -40° wind chill and highs some days around 10° this next week. When I worked in KC we had staff from Dallas move there but many moved back after a year because they couldn't stand what they said was Alaska weather.
In the 50s and 60s weren't heaters optional in cars sent to southern states?
Lol, cold is relative. But Tuesdays low is 12, so yeah... That's pretty cold for around here.
 

HoosierJL

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I'm not familiar with the sensor you speak of.

Next time you have the panel off, could you take a pic of the sensor and your mod and post it here. Thanks!

Trivia: That particular JL panel, under the steering column, costs $25 and is a Lower Cover - Mopar (6AA94TX7AA)
lll.JPG
I'll grab a photo the next time I have it off. In the photo you included though, see the roundish looking vent hole near the top right? That is where the air is drawn in to the sensor. The sensor is directly behind that hole.
 

Rhinebeck01

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I'll grab a photo the next time I have it off. In the photo you included though, see the roundish looking vent hole near the top right? That is where the air is drawn in to the sensor. The sensor is directly behind that hole.
@HoosierJL

I figure I'll have no trouble finding the sensor behind that hole.. I did want to see your insulation job as you said your way of insulating it, netted you an improvement.
 

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