GROUP

MODEL

ELE

2021-2022MY
Sorento HEV, PHEV
(MQ4 P/HEV)

NUMBER

DATE

271 (Rev 3, 07/16/2025)

July 2023

TECHNICAL SERVICE BULLETIN
SERVICE ACTION: INVERTER COOLANT/DEBRIS
SUBJECT:

FLUSHING/REPLACEMENT FOR CLUSTER MESSAGE
“REFILL INVERTER COOLANT” (SA515)

 NOTICE
This bulletin has been revised to include additional information. New/revised sections of this
bulletin are indicated by a black bar in the margin area.
This bulletin provides information to flush out the inverter low-conductivity coolant (BSC-1) on certain 20212022MY Sorento HEV (MQ4 HEV) vehicles produced from September 2, 2020 through September 29, 2021
and Sorento PHEV (MQ4 PHEV) vehicles produced from June 29, 2021 through October 1, 2021, which may
exhibit a “Refill inverter coolant” message displayed on the instrument cluster due to poor flow of
coolant/antifreeze inside the low-conductivity coolant pipe. In most cases, the inverter reservoir tank coolant
may be filled to normal level and no diagnostic trouble codes (DTC)s are stored due to an increase operation
of the electric water pump (EWP) that is 2,800 RPMs or more when checked. Follow the procedure outlined
in this publication to flush out the low-conductivity coolant/debris inside the coolant pipe and replace the
inverter coolant with the new improved formula, the reservoir tank cap label and to distribute the leaflet.
Before conducting the procedure, verify that the vehicle is included in the list of affected VINs.

 NOTICE
A Service Action is a repair program without customer notification that is performed during the
warranty period. Any dealer requesting to perform this repair outside the warranty period will
require DPSM approval.
Repair status for a VIN is provided on KDealer+ (Service → Warranty Coverage → Warranty
Coverage Inquiry → Campaign Information). Not completed Recall / Service Action reports are
available on KDealer+ (Consumer Affairs → Not Completed Recall → Recall VIN → Select Report),
which includes a list of affected vehicles.
This issue number is SA515.

A printed copy is for reference only; publication information can be updated at any time.
Always refer to KGIS for the latest information. After logging in kdealer.com, the newest technical
publications are listed in ‘Service Releases’ and has the latest service information that has been released.

Page 2 of 8

INVERTER COOLANT/DEBRIS FLUSHING/REPLACEMENT FOR

SUBJECT:

CLUSTER MESSAGE “REFILL INVERTER COOLANT” (SA515)

Repair Procedure: (HEV & PHEV)
1a.

Refer

to

Machine

TSB

SST080

Guide’

for

maintenance/cleaning

‘Coolant
initial

Flushing

setup

instructions

and
before

beginning work.
Note: The filter must be cleaned after every use.
1b.

Fill the SST reservoir tank with water (1/2 full).
Note: ’New’ coolant should never be added into
the SST reservoir tank.

2.

Open the hood and remove the service
interlock connector (A).

•

•

HEV

A

HEV

A

PHEV

PHEV
3.

Remove the coolant reservoir cap (B).

B

Note: Disregard pink color coolant in the
images shown (for reference use only).

(HEV model shown above for reference purpose only)
Printed TSB copy is for reference only; information may be updated at any time. Always refer to KGIS for the latest information.

TSB: SA515 (Rev 3) Sorento HEV, PHEV (MQ4 P/HEV) July 2025

Page 3 of 8
SUBJECT:

4.

INVERTER COOLANT/DEBRIS FLUSHING/REPLACEMENT FOR
CLUSTER MESSAGE “REFILL INVERTER COOLANT” (SA515)

Drain the coolant from the reservoir (C) into an
empty container using the SST kit ‘syphon

D

pump’ (D).

C
(HEV model shown above for reference purpose only)

5.

HEV: Remove both the inlet (E) and outlet (F)
circulation hoses (HEV model shown) from the
coolant reservoir (C).

C

E

F

HEV

Connect the Inlet (E) and Outlet (F) hoses from
the

flushing

machine

to

the

detached

circulation hoses (E and F) as shown.
Remove the coolant reservoir (C).

(HEV model shown above for reference purpose only)

PHEV: Remove both the inlet (E) & outlet (F)
circulation hoses (HEV model shown) from the
coolant reservoir (C).

C

Connect the Inlet (E) and Outlet (F) hoses from
the

flushing

machine

to

the

E

detached

circulation hoses (E and F) as shown.

F

Remove the coolant reservoir (C).

6.

PHEV

Turn the ‘Air’ and ‘Pump’ toggle switches of the
flushing machine to the ‘ON’ position to begin

ON

the 1st flush of the coolant path. Follow the
outlined instructions to complete three (3)
coolant flushes for both HEV & PHEV.

ON

NOTE: An additional separate flush of the air
separator is required for PHEV ONLY.

Printed TSB copy is for reference only; information may be updated at any time. Always refer to KGIS for the latest information.

TSB: SA515 (Rev 3) Sorento HEV, PHEV (MQ4 P/HEV) July 2025

Page 4 of 8

INVERTER COOLANT/DEBRIS FLUSHING/REPLACEMENT FOR

SUBJECT:

7.

CLUSTER MESSAGE “REFILL INVERTER COOLANT” (SA515)

Allow machine to run for three (3) minutes.
(HEV and PHEV)
While machine is running:
•

Separately, clean/flush any remaining
coolant/debris

from

the

removed

coolant resorvoir (C) using clean water.
Dry the reservoir (C) using an air gun.

8.

After the three (3) minutes have passed, turn
the flushing machine ‘Pump’ toggle switch to

OFF

the ‘OFF’ position.
ON

Note: Keep the ‘Air’ toggle switch in the ‘ON’
position to drain excess coolant remaining in
line for at least thirty (30) seconds.

9.

Detach the Inlet/Outlet hoses from the vehicle
and then reverse (switch) the flushing machine
Inlet/Outlet hoses to the vehicle as shown.

C

Note: Outlet to Inlet and Inlet to Outlet
10.

Reinstall the coolant reservoir (C) in the reverse
order of removal.

11a.

Turn the ‘Air’ and ‘Pump’ toggle switches of the
flushing machine to the ‘ON’ position and allow

ON

the flushing machine to run for three (3)

ON

minutes.

11b.

After the three (3) minutes have passed, turn
the flushing machine ‘Pump’ toggle switch to
the ‘OFF’ position.
Note: Keep the ‘Air’ toggle switch in the ‘ON’
position to drain excess coolant remaining in
line for at least thirty (30) seconds.

Printed TSB copy is for reference only; information may be updated at any time. Always refer to KGIS for the latest information.

TSB: SA515 (Rev 3) Sorento HEV, PHEV (MQ4 P/HEV) July 2025

OFF
ON

Page 5 of 8

INVERTER COOLANT/DEBRIS FLUSHING/REPLACEMENT FOR

SUBJECT:

12.

CLUSTER MESSAGE “REFILL INVERTER COOLANT” (SA515)

For the third flush, reverse the flushing
machine’s inlet and outlet hoses at the vehicle
as described in Step 5 (without removing the
coolant reservoir) and repeat the flushing
process outlined in Steps 11a and 11b.
HEV ONLY - Skip to step 18.

13.

PHEV ONLY: Locate the two (2) inlet (E) & outlet
(F) circulation ‘quick-connect’ hoses (PHEV
ONLY)

from

the

air

separator

(H)

and

disconnect them from the air separator.

TECH TIP

H

PHEV ONLY: The air separator (H)
may be removed for more access.

14.

Connect the Inlet and Outlet hoses from the
flushing machine to the detached circulation

F