No heat!!! Using Vag and measuring block, Audi tech help appreciated again!
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No heat!!! Using Vag and measuring block, Audi tech help appreciated again!
Ok I ve had no heat now for a long time, I checked the lines going to the heater core, they both seem hot. That lead me to believe I had a flap motor problem. I usually post under Audi0s, so this one may seem repetitive. I looked around online and found that using measuring block4, basic settings, you can run an actuation test of the flap positioning motors. In channels 00, 01, 02 I get error:unknown message type 0x49. Since there s not really any communication, I was thiking it may be a climate control module. Any Audi tech help would be appreciated. Thanks in advance.
Also, when running faults, there are no faults found.
Also, when running faults, there are no faults found.
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Does this model still use the Bosch servos with position potentiometers?
I have a '96 A4. Had a weird issue which seemed to come down to the position-marking potentiometer on the servo getting warn in one place. This potentiometer is built into the servo, and is a horseshoe-shaped piece of conductor with a wiper which moves along it connected to the servo arm. Because the head keeps the temp flap in basically the same place, eventually, the wiper appears to have worn away the conductor in one little place. When the head moved the servo to that one spot, it suddenly got confused and stopped. It would set a trouble code, but the problem was intermittant. I replaced the servo, and it went away.
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From: North Jersey
Not sure about the potentiometers, but its not throwing any codes, either in vag or the climate
I did lower the glove box and watch the flap in front of the blower move, are any of the flaps that control temperature back there as well?
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location of heater blend-flap (natural) servo
The servo for the temp flap is on the bottom of the box. Centered over the central tunnel, at about the midline of the car, screwed into the bottom of the climate-control box, are two electrically-controlled servos. The servo closest to the firewall, with a natural-colored arm, controls the amount of air shunted through the heater core, then blended back into the main air stream. When the arm has moved to the passenger's side, it is full cool. When it moves to the driver's side, it is full hot. The other servo, with a blue control arm, controls the proportion of airflow between the central vents, and the footwell/windshield defrost flap.
If you're not flowing heat, and not setting codes, the most-probable theory is the core needs a backflow. You say the hoses going in and out of the core feel similarly hot. When the system is up to temp, they should feel about the same as the hose running into the radiator - approximately more than a human hand can handle.
The backflow and burping fix is long - I'll try to find some time to post it to the FAQ.
If you're not flowing heat, and not setting codes, the most-probable theory is the core needs a backflow. You say the hoses going in and out of the core feel similarly hot. When the system is up to temp, they should feel about the same as the hose running into the radiator - approximately more than a human hand can handle.
The backflow and burping fix is long - I'll try to find some time to post it to the FAQ.
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Re: location of heater blend-flap (natural) servo
This sounds like my buddy Sweet Bob's car. 2001 A4 with no heat. The heater core has been flushed on a couple different occasions to no avail. The inlet and outlet hoses are basically the same temperature. We ran the VAG-COM, and while there were plenty of codes there was nothing relating to heat. One thing I noticed was that I couldn't run the output tests offered in that climate control menu of VAG-COM.
-Jimal
-Jimal
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