What are the symptoms of No cooling (total) and loss of coolant in the HV tank in SEAT Leon MK4 (PHEV)?

No cold air from vents. Warning light on dashboard

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No cooling (total) and loss of coolant in the HV tank

Q: How to fix No cooling (total) and loss of coolant in the HV tank in SEAT Leon MK4 (PHEV)?

Locate and repair leaks in the high voltage battery cooling system, replace the auxiliary coolant pump, and fill and bleed the system using a scan tool.

in SEAT Leon MK4 (PHEV) (2020-2026)

Symptoms

No cold air from vents
Warning light on dashboard

DTC error codes

B10ABF0, P0C4A00, P16C600

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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

IV - (KL)

Refrigerant: R1234yf Amount (g): 430-480g Oil: PAG YF ISO 46 Oil (ml): 120 - 140ml

III - (5F)

Refrigerant: R134a Amount (g): 450-500g Oil: PAG 46 Oil (ml): 120 - 140ml

II kompresor Denso 7SEU17C

Refrigerant: R134a Amount (g): 500 – 550g Oil: PAG PAO 68 lub PAG ISO 46 Oil (ml): 130 – 150ml

See full specification

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