Heating and Cooling the Cabin - The HVAC System

Kia Soul EV Forum

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Well-known member
Jul 8, 2015
A thread for detailing the components and functioning of the HVAC system of the 2014-2019 Soul EV.
For the 2020 on onwards try Exclusive: details on Hyundai’s new battery thermal management design

Note : Before September 2020 there was no connection between this system and the battery fan. Any mention of Thermal Management on this page is unrelated to heating / cooling of the battery.

Image from - US Kia Promotional material filename - 'PS EV at PEVC March 2014 FINAL v2.pdf' - the link I had is now dead.

The entire climate system in the Soul EV is made by Hanon Systems- their page on the Cluster Ionizer is here - Hanon Systems : Thermal Management Solutions
(Apart from the PTC Positive Temp Coefficient Heater which is made by Daewoo, perhaps Hanon subcontracts this part.)
This company was formerly known as Halla Climate Control Corp who merged with Visteon in 2013 and both then became Hanon Systems. -- see Halla Visteon Changes Corporate Name to Hanon Systems

A June 2018 article about Hanon - 'Diversification key for Hanon Systems' success'


There is report about testing the HVAC system. - http://energy.gov/sites/prod/files/2015/07/f24/vss135_meyer_2015_o.pdf
It seems the heating/cooling system in the Soul EV was extensively tested, and we can see the results.
Winter testing Jan2014 International Falls, MN. Summer testing Jun2014 Death Valley, CA


From an earlier thread on this forum there is some data about the energy use of the heat pump in very cold weather.
see - Winter in Toronto

Also from this thread - Heat Pump vs No Heat Pump
The two versions of the MY2018 Soul EV sold In Korea are the Standard and Economy.
One of the differences is that the Economy version lacks the heat pump.
This causes a 15km reduction in range when the temperature is -7C.

A technical paper by Hanon - Range Extension Opportunities While Heating a Battery Electric Vehicle


Here's a diagram of the heat pump system. It is the compressor that pumps the refrigerant gas / liquid around the system.

From the service manual - here is the heat pump system layout.
see - Kia Soul EV (PS EV) 2015-2020 Service Manual / Heating,Ventilation, Air Conditioning / Heat Pump /


Note: In a heat pump system it is the compressor that pumps the refrigerant around the car. Sometime it is a gas and sometimes a liquid depending on temperature and pressure. The specific type is R134a (1,1,1,2-Tetrafluoroethane).
Occasionally I see references to R-1234yf (2,3,3,3-Tetrafluoropropene) but this seems to be mistaken.


Interesting. Now, my big question is if I have the cluster ionizer in my car. Do you see the "CLEAN MODE" and "ION MODE" described in the service manual in your info screen in any way, or any other way for that matter?

I tried the magic trick, holding the OFF button and pressing the "MODE" button fast several times. It actually worked, and the numbers 00 started flashing, which hopefully means it is installed.

Video ION Cluster test

I also opened the glove department, and removed the cover for the air inlet filter. But I didn't really know what to look for. Is it situated on the right- or left hand side? And is it even possible to spot without disassembling things?
I think the Cluster Ionizer is standard on all our cars. It just gets called 'Clean Air' in some places and 'Cluster Ionizer' in others.

There is a patent for this at Air purifier with cluster negative/positive ion generator


This is a Cluster Ionizer.

About the Cluster Ionizer - from page 977 of the service manual -
1. The function of cluster ionizer is cleaning air by sterilizing and dissolving of air conditioner.
2. The function of cluster ionizer is controlling mold caused by stench of air conditioner and external inflow of air.

The Cluster Ionizer makes a disinfection and decomposition of a bad smell from the air-conditioner or inflow air. And it cleans inside air of a vehicle.
When running an air-conditioner or heater, it starts with "CLEAN MODE" on it and repeats from "CLEAN MODE" to "ION MODE" and from "ION MODE" to "CLEAN MODE" every 15 minutes.
In the CLEAN MODE, the cluster ionizer generates negative ions and positive ions and makes a disinfection and decomposition of a bad smell from the air-conditioner or an inflow air. The cluster ionizer has functions as follows; a deodorization effect, a disinfection effect, and an air-cleaning effect.
It has an operation indicator lamp on the upper side of its display area and shows whether it is operaing or not.
In the ION MODE, the cluster ionizer generates negative ions and cleans inside air of a vehicle.It has an operation indicator lamp on the lower side of its display area and shows whether if is operating or not.

It seems the Cluster Ionizer is accessible from behind the glove box where you change the air con filter.
Cluster Ionizer Replacement
1. 	Disconnect the negative (-) battery terminal.
2. 	Remove the glove box housing. (Refer to Body -"Glove Box Housing")
3. 	Disconnect the cluster ionizer connector (A).
4. 	Remove the screws and then remove the cluster ionizer (B).

There's a post on the Quebec Soul EV Forum about a leaking HVAC system. This seems to be a very rare error.


For those who would be interested. I had an air conditioning problem with my soul ev 2015 (December). Apparently I'm the only one who has the problem right now. According to the dealer's diagnosis, I have leaks (see photos). They will replace the 3 way valve with the pipes... short pieces are in b / O, so it will probably take several weeks or pt months before the air conditioner is functional. They don't know what the problem is. Other kia soul ev may have the problem eventually. So I can share the adventure and some photos that show the problem identified by kia boisvert.

Another subsystem of cooling that does interconnect with the HVAC is the liquid cooling of the electrical components at the front of the car.
Again this is not related in any way to cooling of the battery, and it is not part of the heat pump. The liquid is pushed around the system by an EWP (Electric Water Pump).

Here's a schematic of where the EWP moves coolant around.

From the service manual - here is a schematic of the coolant reservoir.


Here's a picture with the OBC (On Board Charger) and the High Voltage Junction Box moved so you can see the coolant reservoir (the white plastic water tank) and water pump beneath.

The inlet for the coolant into the OBC (On Board Charger) looks like this. You can see the green liquid coming out.

This coolant is an ethylene glycol mix commonly called anti-freeze. I have the green variety in my car, but others have stated blue.


A thread that discusses the Electric Water Pump EWP is here. - Electric Water Pump


A new thread discussing problems with the heating / cooling system - Heat pump stopped working, no apparent cause


The entire HVAC system is managed by an ECU known as FATC (Full Auto Temperature Control).
It is connected on the CAN line to the rest of the car's systems.

The first update to the HVAC system firmware came in September 2020.

TECHNICAL SERVICE BULLETIN: SERVICE ACTION: BMS/FATC OPERATION LOGIC IMPROVEMENT WHILE BATTERY CHARGING (SA427) - This bulletin provides the procedure to upgrade the Battery Management System (BMS) and Full Auto Temperature Control (FATC) software on some 2016-2017MY Soul (PS EV) vehicles, produced from May 21, 2015 through August 29, 2017, in order to improve air conditioning operation while the battery is charging.