Air con faults

[Pharris_uk]

Hi,  have recently bought an 03 Cayenne turbo with many faults, currently I am trying to sort out the air con / climate control.  It does odd things, the temperature usually doesn't adjust as asked, sometime there is hot air and cold air coming from adjacent vents.  It's been tested for leaks and gas.  I have errors 1810 drive motor for temperature valve right, 2100 footwell flap and 1592 air quality sensor.  I have seen other posts that makes me think it is worth replacing the motor relating to the 1810 code, but I am not sure where it is.  Please can anyone help?

[Brett968]

It's the flap motors. There is an air distribution box under the dash in the center of the car; the valves are mounted on either side of this assembly. The valves were redesigned for MY2005+. From the research I did while dealing with this problem on my own car, I concluded that the earlier revision valves fail at an exorbitant rate while the revised valve appears to be very reliable. You could chase the individual fault codes and just replace the motors that are reporting problems. This will be a waste of time and money- you will eventually end up replacing all of the motors. It also will be expensive at ~$150 each (last time I checked).

 

Here's how you can fix the problem for a reasonable price: Purchase a used heater core assembly off ebay from a MY2005+. I got one out of a 2006 for $145 shipped to my door. There is a 2-zone and a 4-zone variant so make sure you get the right one. I stripped off all the motors and then just tossed the plastic housing bits in the trash. I had six separate error codes before the fix. The climate control system has been error code free for the past 1.5 years and I saved over $1k. Most importantly, the climate control system has worked perfectly during this time.

 

You can replace the motors yourself (I did) if you're mechanically inclined but the job is a bit tricky and will take half a day or so.

 

 

Brett

[Pharris_uk]

I am looking into this, thanks very much for your reply Brett.  

[wrinkledpants]

It's the flap motors. There is an air distribution box under the dash in the center of the car; the valves are mounted on either side of this assembly. The valves were redesigned for MY2005+. From the research I did while dealing with this problem on my own car, I concluded that the earlier revision valves fail at an exorbitant rate while the revised valve appears to be very reliable. You could chase the individual fault codes and just replace the motors that are reporting problems. This will be a waste of time and money- you will eventually end up replacing all of the motors. It also will be expensive at ~$150 each (last time I checked).

 

Here's how you can fix the problem for a reasonable price: Purchase a used heater core assembly off ebay from a MY2005+. I got one out of a 2006 for $145 shipped to my door. There is a 2-zone and a 4-zone variant so make sure you get the right one. I stripped off all the motors and then just tossed the plastic housing bits in the trash. I had six separate error codes before the fix. The climate control system has been error code free for the past 1.5 years and I saved over $1k. Most importantly, the climate control system has worked perfectly during this time.

 

You can replace the motors yourself (I did) if you're mechanically inclined but the job is a bit tricky and will take half a day or so.

 

 

Brett

 

Did you have to pull the top of the dash, or were you able to reach everything from down below?

[Brett968]

Did you have to pull the top of the dash, or were you able to reach everything from down below?

 

The entire job is done from below- no need to remove the dash panel. I would recommend acquiring the workshop manual before attempting. Another advantage of purchasing the entire heater core assembly is that you can easily see how everything goes together on the donor assembly.

[Pharris_uk]

On a right hand drive car the left hand motor control valve is very easy to get to, the right hand one is tough and involves removing the foot brake assembly. Garage charged 3 hours labour. The heater core assembly is also not easy to come by in the uk but individual motors are quite cheap, hence I only did the one motor that I needed. Temperature is now properly controlled hot and cold, but I'm about to post another question as it only blows properly cold intermittently, often is just ambient cold. Once again, thanks for the help though.

[Brett968]

On a right hand drive car the left hand motor control valve is very easy to get to, the right hand one is tough and involves removing the foot brake assembly. Garage charged 3 hours labour. The heater core assembly is also not easy to come by in the uk but individual motors are quite cheap, hence I only did the one motor that I needed. Temperature is now properly controlled hot and cold, but I'm about to post another question as it only blows properly cold intermittently, often is just ambient cold. Once again, thanks for the help though.

Your 1592 fault code suggests to me that the motor controlling the fresh air recirculation valve is also faulty. If fresh air is entering during cooling instead of recirculated air, perhaps this is why it isn't blowing as cold sometimes?

 

On left-hand drive cars this motor is mounted on the blower motor assembly and is very easy to replace (5-10 min). It is the same style motor as all the flap motors mounted on the air distribution box.