What are the symptoms of Hissing from vents and slow loss of refrigerant in Hyundai Grandeur?

No cold air from vents. Different temperature on both sides of the cabin. Weak or no heating in winter. No blowing from vents

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Hissing from vents and slow loss of refrigerant

Q: How to fix Hissing from vents and slow loss of refrigerant in Hyundai Grandeur?

A gigantic repair action (leaked into post-warranty cases in Korean/US courts). Dismantling the interior and inserting a clean, technologically undamaged evaporator core. EBA-GARU! If your friend asks you why he has white snow in the front on black windshield wipers when the air conditioning is on... Open the trunk, take a Hazmat suit, because he's breathing in the toxic flaky HVAC evaporator body.

in Hyundai Grandeur (2015-2019)

Symptoms

No cold air from vents
Different temperature on both sides of the cabin
Weak or no heating in winter
No blowing from vents

DTC error codes

Brak

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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

3,3 i/3,8 i/2,2 D CRDi

Refrigerant: R134a Amount (g): 480 – 520g Oil: PAG PAO 68 Oil (ml): 140 – 160ml

See full specification

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