What are the symptoms of Slow loss of refrigerant or A/C system leakage in Volkswagen ID.4?

Problem visible at standstill or in traffic. Frost or ice on pipes under the hood

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Slow loss of refrigerant or A/C system leakage

Q: How to fix Slow loss of refrigerant or A/C system leakage in Volkswagen ID.4?

Replacement of the G395 sensor (modernized) and, in Audi, verification and repair of the LIN cable insulation. The sensor has a Schrader valve - it can be unscrewed without removing gas from the system. Note: In electric models, ID is a very massive fault that turns off the AC with service action 87i1.

in Volkswagen ID.4 (2008-2024)

Symptoms

Problem visible at standstill or in traffic
Frost or ice on pipes under the hood

DTC error codes

00819

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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

E21 (Wersja standardowa R1234yf)

Refrigerant: R1234yf Amount (g): 460g Oil: POE (nieprzewodzący) Oil (ml): 120ml

E21 (Opcja pompa ciepła R744)

Refrigerant: R744 Amount (g): 420g Oil: PAG (specjalny do CO2) Oil (ml): 200ml

Bez Pompy Ciepła (Standard)

Refrigerant: R1234yf Amount (g): 460g Oil: PAO 68 AA1 Oil (ml): 120ml

See full specification

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Slow loss of refrigerant or A/C system leakage

Symptoms

DTC error codes

A/C Technical Specifications

Other problems in ID.4

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