GROUP

MODEL

ELE

2019-2022MY
Niro EV (DE EV)

NUMBER

DATE

270 (Rev 3, 03/03/2025)

April 2023

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

FLUSHING/REPLACEMENT FOR CLUSTER MESSAGE
“REFILL INVERTER COOLANT” (SA512)

 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 20192022MY Niro EV (DE EV) vehicles produced from May 10, 2019 through October 4, 2021, which may exhibit a
“Refill inverter coolant” message displayed on the instrument cluster due to poor flow of coolant/antifreeze
inside the coolant pipes. In most cases, the inverter reservoir tank coolant may be filled to normal level and
no DTC’s are stored due to an increase operation of the electric water pump (EWP) that is 2,450 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 new formula (BSC-2). 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 SA512.
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 9
SUBJECT:

INVERTER COOLANT/DEBRIS FLUSHING/REPLACEMENT FOR
CLUSTER MESSAGE “REFILL INVERTER COOLANT” (SA512)

Repair Procedure:
1.

If the vehicle has General Type Coolant
(green), this service action does not apply.
Submit a KVID photo of the green coolant filled
reservoir and use Op Code 230020R2.
If the vehicle has Low-Conductivity Coolant
(BSC-1) (blue), continue to step 2 to replace it
with (BSC-2) to complete this service action.

2.

Select ‘Data Analysis’ icon.

3.

Select ‘BMS’ icon.

4.

Ensure the ‘Battery BTMS Valve Control
Mode’ is in ‘Combined Mode’.

 NOTICE
If ‘Battery BTMS Valve Control Mode’
is in ‘Separated Mode’, turn the
ignition ‘ON’ and ‘OFF’ to change to
‘Combined Mode’.

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

TSB: SA512 (Rev 3) Niro EV (DE EV) April 2023

Page 3 of 9

INVERTER COOLANT/DEBRIS FLUSHING/REPLACEMENT FOR

SUBJECT:

5a.

CLUSTER MESSAGE “REFILL INVERTER COOLANT” (SA512)
Refer to TSB SST080 ‘Coolant Flushing
Machine

Guide’

for

maintenance/cleaning

initial

setup

instructions

and
before

beginning work.
Note: The filter must be cleaned after every
use.
5b.

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

6.

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

A
7.

Remove the coolant reservoir (C) cap (B).

B

 NOTICE
Coolant reservoir cap has reverse
threads.

C

8.

Drain the coolant from the reservoir (C) into an

D

empty container using the SST kit ‘syphon
pump’ (D).

C

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

TSB: SA512 (Rev3) Niro EV (DE EV) April 2023

Page 4 of 9

INVERTER COOLANT/DEBRIS FLUSHING/REPLACEMENT FOR

SUBJECT:

9.

CLUSTER MESSAGE “REFILL INVERTER COOLANT” (SA512)

Remove the two (2) inlet (E) and outlet (F)
circulation hoses from the coolant reservoir (C).

10.

C
F

Connect the Inlet/Outlet hoses from the
flushing machine to the detached circulation
hoses (E and F) as shown.

E
11.

Close the reservoir degassing valve (G).

 NOTICE
G

If the reservoir tank degassing hose
does not have a valve, cut off the flow
using a hose pinch-off plier.

12.

Turn the ‘Air’ toggle switch on the flushing
machine to the ‘ON’ position (Pump switch
‘OFF’) and ‘Close’ the valve to begin the air
drain of the coolant pipe.
Note: Allow the machine to run for al least
two (2) minutes.

13.

Run the air for two (2) minutes and then turn
‘OFF’.

14.

Reconnect the two (2) inlet (E) bottom, and
outlet (F) upper circulation hoses to the

C

reservoir (C).

F

E

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

TSB: SA512 (Rev 3) Niro EV (DE EV) April 2023

Page 5 of 9

INVERTER COOLANT/DEBRIS FLUSHING/REPLACEMENT FOR

SUBJECT:

15.

CLUSTER MESSAGE “REFILL INVERTER COOLANT” (SA512)
Remove the Motor & Reduction Gear under
cover (H).

Tightening torque for bolts:
2.9 – 4.3 lb.ft (3.9 – 5.9 N.m)

H
16.

Remove the HV Battery lower cover (I).
Tightening torque for bolts:
2.9 – 4.3 lb.ft (3.9 – 5.9 N.m)

I
17.

Disconnect the lower radiator hose (J).

 NOTICE
Capture the drained coolant into the
drain pan.

J

18.

Remove the adapter from the flushing machine
‘outlet’ hose (K).

19.

Connect the ‘outlet’ hose from the flushing
machine to the radiator connection (K) to the
radiator as shown.

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

TSB: SA512 (Rev3) Niro EV (DE EV) April 2023

Page 6 of 9
SUBJECT:

20.

INVERTER COOLANT/DEBRIS FLUSHING/REPLACEMENT FOR
CLUSTER MESSAGE “REFILL INVERTER COOLANT” (SA512)

Disconnect the electric water pump (EWP) inlet
hose (L).

21.

L

Connect the ‘inlet’ hose from the flushing
machine to the EWP inlet hose (L) as shown.

22a

Turn the flushing machine ‘Air & Pump’ toggle
switches to the ‘ON’ position and ‘Open’ the
valve.
Note: Allow the machine to run for al least
five (5) minutes.

22b

After the five (5) minutes have passed, ‘Close’
the valve and turn the pump ‘OFF’. Run the air
for two (2) minutes and then turn ‘OFF’.

23.

Detach both of the ‘Inlet/Outlet’ hoses from the
vehicle and then reverse (switch) the flushing
machine ‘Inlet/Outlet’ hoses to the vehicle ‘Inlet’
hose to radiator and ‘Outlet’ hose to EWP.