Air conditioning works in one zone

[Hendlerj]

Two of my 200s have been with me since birth. I have never had a single issue in either of them (before I built one and created some complications by messing with the perfection of Toyota engineering.)

I recently bought a third one with 113k miles on it for the nanny to shuttle the kids around town. The air conditioning blows cold for the driver but not cold for the other three zones.

Any ideas?

 

[bloc]

Check the recirc door to see if it’s operating with the fresh air/recirc button. Don’t try to move it by hand!

If that’s good, you can try an AC servo reset, but you’ll need techstream for that procedure.

 

[Sandroad]

What year? There is a TSB for HVAC servo problems.

https://static.nhtsa.gov/odi/tsbs/2021/MC-10187278-9999.pdf

Also, after you check the cabin filter control as suggested by @bloc (if it’s broken that can cause issues), some members on here have had things reset by disconnecting the battery for a few minutes.

 

[Hendlerj]

What year? There is a TSB for HVAC servo problems.

https://static.nhtsa.gov/odi/tsbs/2021/MC-10187278-9999.pdf

Also, after you check the cabin filter control as suggested by @bloc (if it’s broken that can cause issues), some members on here have had things reset by disconnecting the battery for a few minutes.

2013

 

[Hendlerj]

I took it to the dealership. I told them about the TSB so helpfully provided here. They decided there was a coolant leak in the back. They fixed the leak today. Of course, it did not solve the problem. They now want to replace another piece (pictured here) but this is very expensive supposedly because of where it is located. They are quoting 7 hours of labor (almost $2k with parts). I think it still won't fix it. Is this group convinced that the fix is in the TSB if the air was cold for the driver and warm for the front passenger and rear?

 

[Hendlerj]

They are claiming freon leaks, but I don't understand how that would be the culprit. Is there a separate freon reservoir for the driver than for the rest of the car?

 

[bloc]

They are claiming freon leaks, but I don't understand how that would be the culprit. Is there a separate freon reservoir for the driver than for the rest of the car?

No, but these computer-controlled climate systems can do really weird things when they don't get the response they expect to a given input. You aren't the first to report low refrigerant leading to weird dash vent selection.

The TSB is only for years 16-17, for the record. Your 2013 has a different wiring harness and big chunks of the electronics were updated as well.

A leak in that spot is actually pretty common on vehicles with significant corrosion. Your location shows as Vermont, so I'm assuming you do have corrosion. Usually it's the lower, easier to access part, but not always.

 

[Hendlerj]

No, but these computer-controlled climate systems can do really weird things when they don't get the response they expect to a given input. You aren't the first to report low refrigerant leading to weird dash vent selection.

The TSB is only for years 16-17, for the record. Your 2013 has a different wiring harness and big chunks of the electronics were updated as well.

A leak in that spot is actually pretty common on vehicles with significant corrosion. Your location shows as Vermont, so I'm assuming you do have corrosion. Usually it's the lower, easier to access part, but not always.

So, in your opinion, it is possible that the culprit is a leak in the second part? Is it reasonable that it would be seven hours to fix that leak? The one they did today was quoted at $300 which was far easier to swallow than $2k. Yes, the car has northeast corrosion.

 

[bloc]

So, in your opinion, it is possible that the culprit is a leak in the second part? Is it reasonable that it would be seven hours to fix that leak? The one they did today was quoted at $300 which was far easier to swallow than $2k. Yes, the car has northeast corrosion.

Yeah it is possible. The one they already changed is accessible from the bottom of the vehicle, so not much disassembly required. It joins with the part they now say they need to change, and there is an o-ring at that joint. Both parts are aluminum. If the corrosion attacked where the o-ring lives in that joint the upper part can be bad too. That one actually goes through the floor of the vehicle and connects the under-body pipe to the HVAC unit itself inside.

Getting that one out involves removing the large interior trim panel on the driver's side of the third row, that rear seat if it's in place, and the whole rear HVAC unit nestled in behind that panel. All to get a little 4-6" long aluminum pressure pipe out, but unfortunately that part is the other half of the joint that is corroded.

I'd have them evaluate the condition of the coolant lines that run the rear heat too. Could be a nice little "while you're in there" job that shouldn't add much cost, as they'll have to loosen those coolant lines anyway to remove the rear HVAC unit.

 

[vipergrhd]

Two of my 200s have been with me since birth. I have never had a single issue in either of them (before I built one and created some complications by messing with the perfection of Toyota engineering.)

I recently bought a third one with 113k miles on it for the nanny to shuttle the kids around town. The air conditioning blows cold for the driver but not cold for the other three zones.

Any ideas?

You didn't mention how old are the vehicles, yes the system is not leak proof. Coolant leak will not affect your a/c output the problem is totally non related regardless of what BS they tell you. Simple way of checking your HVAC doors if they are closing/adjusting as they should is get a thermometer if you could put it in full heat for both pass. and driver side and check the temp. difference if you get the same output then the doors are good. Most dual temp. system is just controlled by the actuators which is connected to doors inside your HVAC housing, you have a single evaporator and heater core (I hope) the rear unit do have a seperate unit (Evap & heater core) I would have the system check for low refrigerant and maybe add dye if they recharge the system the correct amount does make a difference so avoid the add a can of freon if possible if the system is full and gauge readings are good then you could have a clogged evaporator.