Air Conditioning (blowing hot) fix - or just deal with it?

[BiggerWhiskey]

I've already read through MANY posts on the forum and other online groups (Facebook, Reddit, etc).....but I seem to be getting the A/C gremlin every now and then when I start up the vehicle too quickly (where it will just blow hot air regardless of what I do). The only thing to fix it is exit the vehicle, lock it, and wait about 10-15 minutes....then it will blow ice cold like nothing ever happened.

My main question - is there an actual fix from the dealers, or is this just a software / wiring glitch that some owners have to live with? My vehicle build is 02/24....Im not sure if later 24 models have better luck with this...or its just hit and miss...

If so - its really not that big of a deal....I just want to make sure there isn't an actual fix from the dealers before I just chalk this one up to being a Grenny Gremlin for the rest of its life.

Thanks!

 

[anand]

Technically the module reset time after locking is 5min 30 seconds from what we were told by the project manager So you don't need to wait 10-15 minutes...

I've had this happen maybe a half dozen times in the past 10 months or so and am just living with it. Unless it has changed in recent months, the last time I investigated it the "fix" is to replace the HVAC box as it is sold as one part number, and hope that the new one doesn't do it. With that being said, replacement involves removing the dash, so time that with any other things you may need at the same time.

 

[BiggerWhiskey]

Technically the module reset time after locking is 5min 30 seconds from what we were told by the project manager So you don't need to wait 10-15 minutes...

I've had this happen maybe a half dozen times in the past 10 months or so and am just living with it. Unless it has changed in recent months, the last time I investigated it the "fix" is to replace the HVAC box as it is sold as one part number, and hope that the new one doesn't do it. With that being said, replacement involves removing the dash, so time that with any other things you may need at the same time.

Yeah.....its more of just an annoyance....but you just saved me some time if its only a 5.5 minute reset...hah...

I feel like having them rip out the dash and start replacing all that might lead to more problems.....I'll live with it....just have to remember to always to my "boot up sequence" like everyone else...thanks for the info!

 

[anand]

I feel like having them rip out the dash and start replacing all that might lead to more problems.....I'll live with it....just have to remember to always to my "boot up sequence" like everyone else...thanks for the info!

Ironically, I was telling my better half about the boot up sequence while we were out in Moab 2 weeks ago, and I accidentally didn't wait before starting the truck and the next key cycle it did the full heat "feature". Coincidence? I think not!

 

[Tom109]

I had my 9/23 build in for for service Jan 2025. With AC use It showed drips on the driver floor mat (LHD). Dealer had a service bulletin that pulls the whole dash out and bleeds the coolant system. I haven’t had any drips and have not had the hot/AC recurrence either.

 

[anand]

I had my 9/23 build in for for service Jan 2025. With AC use It showed drips on the driver floor mat (LHD). Dealer had a service bulletin that pulls the whole dash out and bleeds the coolant system. I haven’t had any drips and have not had the hot/AC recurrence either.

Mine drips enough in a 7-8hr drive that it'll fill nearly half of the "divots" on the OEM rubber floor mat with water... I'm saving that repair until my TTC acts up more frequently (a handful of times over the past 4-5 months it dings saying my seatbelt isn't on, but only in the TTC, the infotainment recognizes my seatbelt is on). One big dash pulling adventure only. Hopefully

 

[Skydance]

Whole dash doesn’t need to come out. Just needs purging and coolant topping up to max on both reservoirs on a cold engine. This will fix the condensation dripping. On a recent software and module update, this has fixed the behaviour of auto too. Mines a May 2023.

 

[anand]

Whole dash doesn’t need to come out. Just needs purging and coolant topping up to max on both reservoirs on a cold engine. This will fix the condensation dripping. On a recent software and module update, this has fixed the behaviour of auto too. Mines a May 2023.

The official technical service bulletin here in the US for condensation dripping in the interior is to replace the seal around the condensate drain, which requires removing the HVAC box, which requires removal of the dash

 

[Skydance]

The official technical service bulletin here in the US for condensation dripping in the interior is to replace the seal around the condensate drain, which requires removing the HVAC box, which requires removal of the dash

There are different types of leaks identified. If the leak runs droplets of water on the side of the CENTRE tunnel under the passenger glovebox (UK spec). You can see the droplet running down. This is the fix for the condensation leak. I’m not sure if we are talking about the same leak.

 

[anand]

There are different types of leaks identified. If the leak runs droplets of water on the side of the CENTRE tunnel under the passenger glovebox (UK spec). You can see the droplet running down. This is the fix for the condensation leak. I’m not sure if we are talking about the same leak.

Yes, for that leak, the US TSB states to replace the seal - https://www.theineosforum.com/resources/footwell-water-intrusion.48/

 

[Skydance]

Yes, for that leak, the US TSB states to replace the seal - https://www.theineosforum.com/resources/footwell-water-intrusion.48/

I’ve just read that TSB and it says leak down the tunnel and leaks in the footwell. Mine only leaked droplets down the centre tunnel onto the mats.

Have you had the air con on and got underneath to identify where the leaks are actually coming from. Like I said, there seems to be more than one types of leaks.

 

[anand]

I’ve just read that TSB and it says leak down the tunnel and leaks in the footwell. Mine only leaked droplets down the centre tunnel onto the mats.

Have you had the air con on and got underneath to identify where the leaks are actually coming from. Like I said, there seems to be more than one types of leaks.

Footwell is where the droplets would go if the mat is not in place (here in the US at least the mats are optional. I know when I don't have the OEM rubber mat in place it will drip down and go under the removable floor section)

Mine happens only with the aircon on and is from condensation

 

[Skydance]

Footwell is where the droplets would go if the mat is not in place (here in the US at least the mats are optional. I know when I don't have the OEM rubber mat in place it will drip down and go under the removable floor section)

Mine happens only with the aircon on and is from condensation

Ok, with process of elimination and the sake of ripping out the whole dashboard. Have you tried doing what I recommended first. I did this myself by just topping up the coolant on both reservoirs and I don’t have anymore condensation dripping even in hot weather when the air con is on.

You be surprised how much coolant it needs topping up. Lift up the bonnet into service mode and have a look. If it doesn’t work then the dealer can follow the TSB.

 

[Clark Kent]

There is a new TSB dated April 15, 2025 on the NHTSA website for water in the footwell. The latest fix is to add some lagging around a section of the HVAC cold pipe. Repair time is 0.3hrs with minimal disassembly.

Vehicle Detail Search - 2024 INEOS GRENADIER | NHTSA

www.nhtsa.gov