Q7 Audi Q7 4L little problems

[Veseli1094]

Hi everyone,

i bought few month ago audi Q7 4L fully loaded with equipment.

As far everything works but i started to have some issue.

1.
My Q7 have 4 zone climate control.
First and most important is that my A/c blows cold air in front, but on the rear it blows warm air.
I can post scan but car does not have any codes regarding front or back A/C only one stupid code for air quality sensor but that souldnt be causing this problem.

i need to tell you that yes my A/C is full whit gas, i double checked all motors and actuators on rear HVAC unit, and blower is spining allso, car doesn not have any A/C leak. Also i tried and replace front and rear climatronic and removed CP and still no fix.

i urgently need soultion for this problem because i live in Europe and warm weather is coming and i am driving my wife and my baby behind.



2. second problem is that car is trowing 2 stupid codes in Address 42 (drive door) and address 52 (passenger fron door) that both my rear left and right door contorl module does not have any signal or coumincation.
I replaced both rear modules with few spare one fron parts yard, and replaced front passenger module also with few others and still same error codes.

I realy dont mind this codes on door modules because all works fine except child lock, whenever i start car and moving, child lock kicks in and as my wife is driving in rear seats with baby everytime i stop car and we go out i need to open her door, it is not problem but it is anoying. I tried screw on inner door with lock picture and i rotate it but it doesnt do anything.

thanks for your help.

 

[NHN]

Check if the rear modules are bus linked to the fronts as on some chassis & years, Audi decided to remove direct canbus feeds to rear doors & use the front canbus only & create a bus between the front & rear modules, ideally wiring diagram needed, but it maybe some anomaly linked to this, speculation ATM as I dont know your car at all, but seen similar things.

Check coding for 42 & 52 to see if it's got anything related to rears via fronts bus etc.

Assume you can access your rear door modules directly in 62 & 72?

Tbh climate issue sounds like a flap, motor issue imho, do a basic setting in HVAC to reset all motors, flaps, see if this corrects, otherwise you'd have to dig deep into the system & check if things are moving or not when told too.

 

[Veseli1094]

Check if the rear modules are bus linked to the fronts as on some chassis & years, Audi decided to remove direct canbus feeds to rear doors & use the front canbus only & create a bus between the front & rear modules, ideally wiring diagram needed, but it maybe some anomaly linked to this, speculation ATM as I dont know your car at all, but seen similar things.

Check coding for 42 & 52 to see if it's got anything related to rears via fronts bus etc.

Assume you can access your rear door modules directly in 62 & 72?

Tbh climate issue sounds like a flap, motor issue imho, do a basic setting in HVAC to reset all motors, flaps, see if this corrects, otherwise you'd have to dig deep into the system & check if things are moving or not when told too.

Hi thanks for replay,

for door modules i will try tomorow to chekc coding.

As for A/C issue i found that someone from previous owner decided to cut rear A/C lines (probably due to rear evaporator leak) and thank god i found used but good A/C lines that i am going to replace tonight and charge A/C lines with gas to see if and where is leak.

 

[NHN]

Oh dear what some people do.

Maybe they also did some trickery on doors.

 

[Veseli1094]

Oh dear what some people do.

Maybe they also did some trickery on doors.

i looked already on doors wiring etc didint find anything unusual. But that child lock safety everytime is ANOYING AS F******

As for A/C i replaced lines and now need to take out rear evaporator and try to test it for leak somehow

 

[Veseli1094]

Oh dear what some people do.

Maybe they also did some trickery on doors.

i forgot to inform you that i replaced A/C lines that was broken, tester read evaporator and charged A/C and its not leaking enywhere but still A/C lines that go to rear of car is not cold and i need to dissasamble lines all the way to where they splits to front and rear and start from there because from there rear lines are not cold.