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No blowing / The blower does not work and fogging the windows from the inside

Q: What are the symptoms of No blowing / The blower does not work and fogging the windows from the inside in Audi A4 (B8/8K)?

No blowing from vents. Fogging windows. Frost or ice on pipes under the hood. Air conditioning does not turn on

Q: How to fix No blowing / The blower does not work and fogging the windows from the inside in Audi A4 (B8/8K)?

Physical unblocking of all body drainage channels in the windshield + replacement of the damaged V2 blower motor. Blower cost: PLN 300-600. Prevention: cleaning the lining every season. PREVENTION: Once a year, remove the plastic cover under the glass and pull out the leaves. This 10-minute service saves PLN 600 for the blower motor. Symptom of flooding: after rain, the blower hums or does not start.

in Audi A4 (B8/8K) (2008-2017)

Symptoms

No blowing from vents
Fogging windows
Frost or ice on pipes under the hood
Air conditioning does not turn on

DTC error codes

Blower Motor V2 - open circuit

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Technical diagnosis (Premium)

Recognized technical fault:

Auxiliary controller voltage instability detected

Technical analysis

Detailed analysis of HVAC controller operation parameters, CAN bus data readings, and diagnostic signal waveforms. Purchase PRO access or log in to read the full fault analysis.

Confirmed solution

Complete step-by-step repair procedure including module non-volatile memory reset, sensor calibration, and correct wiring routing. Unlock the full report to see the instruction.

Parts needed

Filters ferrite anti-interference / noise suppressor
Auxiliary starting battery (depending on cell status)

Workshop hacks

Important workshop tips for mechanics regarding bypasses without expensive control module replacement and manufacturer software service bulletins.

TSB / TPI service bulletins

TSB-24-HVAC-01TPI-2068943/2

A/C Technical Specifications

(B9)

Refrigerant: R1234yf Amount (g): 580g Oil: PAG ISO 46 YF Oil (ml): 110ml

(B9)

Refrigerant: R1234yf Amount (g): 480-530g Oil: PAG YF ISO 46 Oil (ml): 120 - 150ml

S4 / RS4 (B9) - Wersje z czynnikiem R134a (590g) oraz R1234yf (525g)

Refrigerant: R134a / R1234yf Amount (g): 525 / 590 ±15g Oil: ND-12 / SP-A2 / PAG46yf Oil (ml): 100 / 110ml

See full specification

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