HVAC Fault

[Westyfield2]

Hi,

I have this fault. I clear it but then a week later it returns.

                Address 28: HVAC, Rear       Labels: 4G0-919-158.clb
Control Module Part Number: 4G0 919 158 C    HW: 4G0 919 158 C
  Component and/or Version: KLIMA FOND    H07 0062
           Software Coding: 02
            Work Shop Code: WSC 02391 785 00200
              ASAM Dataset: EV_ClimaContrUnitRearUDS 002015 (AU57)
                       ROD: EV_ClimaContrUnitRearUDS.rod
                      VCID: 2F6DEEC976E81846D7-807A
1 Fault Found:

0034 - Motor for Rear Right Upper Body Vent 
          B10D4 21 [008] - Signal Amplitude Too Low
          Intermittent - Confirmed - Tested Since Memory Clear

Any ideas on how to investigate? I guess it could either be wiring or the motor.

The car is an A6 C7, with the optional extra of quad climate.

9AQ
Deluxe 4-zone automatic air conditioning, includes front control panel with digital display, separate temperature control for the driver and front passenger sides. There are additional controls with digital display in the rear with separately adjustable temperature and blower settings for right and left side (rear functions can also be set from the front controls.) There are additional air vents in the B-pillars and automatic recirculation by means of air quality sensor, use of residual heat, separate regulation of footwell temperature and ventilated glove compartment with a choice of 3 climates: gentle, medium and intensive

[spife]

Any update on this issue? I am getting this too but there is air coming out from the vent. Maybe it's just a wiring issue?

[Pharm07]

Bumping this Thread as I have this same fault and no air coming out of the rear right vent. Any help would be appreciated.

[Alister]

Perform a 'basic settings' adaptation of the rear vents using either VCDS or ODIS.

[Pharm07]

Thanks Alister for the reply. I just recently got my vagcom so still getting used to it. What will the adaptation do once ran? What I am looking for?

[s4nicetry]

Bumping this Thread as I have this same fault and no air coming out of the rear right vent. Any help would be appreciated.

Interesting I have the same fault, same vent. Haven't really looked into it yet though.

[Alister]

It'll check/test the operation of the flaps to open/close the vent off.

Should result in the fault code clearing and not coming back (unless there is a permanent issue with the flap or potentiometer).

[Pharm07]

Good to know...I'll give it a shot tomorrow and see what happens

[Pharm07]

well ran the program and it came back with the same fault code. I am guessing that means there is a component that is faulty?

[Alister]

Sounds like it, yes.

Out of interest, have you removed the rear vents at any stage?

[Pharm07]

I've had the car a little over a year now and I've never messed with them not sure if in the past they ever were.

[Pharm07]

To add to this. I did pop out the center console vent assembly and unplug the unit. I turned on the AC and tried different settings to try and get airflow out of that right duct and nothing. Tried finding a diagram of how this system is laid out but can't come across a detailed spec. Appears that main trunk carries airflow from the front on the car to the back and splits off to the B-pillar vent and the center console vent? I am assuming there is flap at that junction controlled by a motor and most likely my problem? Does the whole console have to be removed..if so how? Appreciate any help.

[lauretiu]

To add to this. I did pop out the center console vent assembly and unplug the unit. I turned on the AC and tried different settings to try and get airflow out of that right duct and nothing. Tried finding a diagram of how this system is laid out but can't come across a detailed spec. Appears that main trunk carries airflow from the front on the car to the back and splits off to the B-pillar vent and the center console vent? I am assuming there is flap at that junction controlled by a motor and most likely my problem? Does the whole console have to be removed..if so how? Appreciate any help.

I would definitely be very happy to know how to do that. I have the same issue. With mine I know the flap is broken. But i don't know how yo take everything apart. I did it to a certain level and that's it I'm stuck now how to take the rest out. Any help someone with a little more experience?

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[lauretiu]

Long story short I replaced that vent that was in the central console under the arm rest did the adaptions with obd11 and still having troubles. I can't figure this thing out for the life of me Screenshot_20190617-194434_OBDeleven.jpegScreenshot_20190617-194437_OBDeleven.jpeg20190611_123636.jpeg

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[infinitereality]

I'm curious as well, noticed when I scanned my car last night I have the same code

[36dbldz]

Me too

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[gk1]

Assuming VCDS text is correct.
"Motor for Rear Right Upper Body Vent"

Right Rear Upper Body Vent Motor V316
It looks like p/n 4G0857042D with both motors as lauretiu is holding above.
Replacing that may work for OP's fault.

lauretiu's fault is shown as a short circuit somewhere, but the text state "position sensor in left rear upper body..." which could be referring to the two motors in the front of the car for the left rear or any wiring...it is hard to tell.
Left Rear Air Door Motor V239
Left Rear Temperature Door Motor V313
Sadly a pro diag might be necessary as it looks like VCDS and OBDEleven are not detailed enough to pinpoint the issue. It might be worth the diag time at the dealer for them to pinpoint the issue and then just pay the diag fee and replace it yourself.