GROUP

NUMBER

HYBRID CONTROL
DATE

Technical Service Bulletin

23-HC-001H-1
MODEL(S)

AUGUST 2023

SONATA HYBRID
(YF HEV)

DTC P1B25, P1B76, P1B77, P0A0D

SUBJECT:

This TSB supersedes TSB# 23-HC-001H to simplify the subject header, better define
inspection path in DTC List and add clarification in Step 6 for identifying non-genuine fuses.

 IMPORTANT
If the affected part is beyond factory warranty, submit a Prior Approval request for goodwill
consideration prior to performing the work.
Description: On certain Sonata hybrid (YF HEV) vehicles, the HEV safety plug or power relay assembly
(PRA) may cause the following symptoms and one or more current related DTCs. Follow the Service
Procedure before diagnosing the hybrid battery. Please review the following instructions carefully to
determine applicability depending on the model year of your vehicle.
Warning light:
• No “EV Ready” mode, or “Ready” light blinks on and off
• “Check Engine” warning light on
• Charging system warning light on
• “Wrench” symbol (service indicator) blinks on and off
Drivability symptoms:
• Vehicle will not move from a stop or gasoline engine will not turn on.
• Warning in the instrument cluster display: “Hybrid System Warning! Safely stop and Do Not
Drive” and/or alarm sound.
DTC List:
DTC

Description

Inspect

P0A0D

High Voltage System Interlock Circuit High

HEV safety plug

P1B25

High Voltage Path Fault

HEV safety plug → PRA

P1B76

High Voltage Relay Fault

HEV safety plug → PRA

P1B77

High Voltage Precharging Fault

HEV safety plug → PRA

For 2013-2015MY Sonata Hybrid (YF HEV): Please refer to “TSB 23-01-054H Safety Plug and Fuse
Inspection/Replacement (Service Campaign 994)” first if open on the vehicle before troubleshooting
Power Relay Assembly (PRA). If no open campaigns are found, proceed with this TSB.

Applicable Vehicles: 2011-15MY Sonata Hybrid (YF HEV)

Circulate To: General Manager, Service Manager, Parts Manager, Warranty Manager, Service
Advisors, Technicians, Body Shop Manager, Fleet Repair

DTC P1B25, P1B76, P1B77, P0A0D

SUBJECT:

Parts Information:
Model

Part Name

Section

2011-15MY
Sonata Hybrid
(YF HEV)

Power Relay Assembly
(PRA)

PNC

Part Number

37514

37514-4R000

37586

37586-4R000AS
37586-4R002
*Refer to parts
catalog for the
applicable safety
plug P/N

37-371
2011-15MY
Sonata Hybrid
(YF HEV)

SST Information:
Tool Name

EV Safety Plug

Figure

Electrical Insulating
Safety Glove/Protector
Set*

Tool #

Remarks

J-48755-10H (small)
J-48755-11H (medium)
J-48755-12H (large)

Order from
Hyundai.servicesolutions.com,
“EV Tools”

*Use only rubber insulating gloves that meet or exceed ASTM D120 standards (1000 volts AC/1500
volts DC).
Warranty Information:
Model

Op. Code

Operation

Op.
Time

Causal Part

All Sonata
Hybrid
(YF HEV)

37514R1H

Power Relay Assembly
Replacement

1.0
M/H

37514-4R000

37586R1H

Safety Plug Inspection &
Replacement

0.2
M/H

37586-4R001

37514RQ0

GDS operation

0.3
M/H

N/A

2011-2012
Sonata
Hybrid
(YF HEV)

Nature
Code

Cause
Code

E23

ZZ6

NOTE 1: Normal warranty applies.
NOTE 2: Submit claim on Claim Entry Screen as “Warranty” type.
NOTE 3: Refer to the latest Digital Documentation Policy for repair validation requirements.
NOTE 4: The incident parts are subject to callback through the normal Warranty Technical Center
(WTC) parts return process. Claim is subject to debit if the part is not returned.
NOTE 5: If a part is found in need of replacement while performing this TSB and the affected part is
still under warranty, submit a separate claim using the same repair order. If the affected part is out of
warranty, submit a Prior Approval request for goodwill consideration prior to performing the work.

TSB #: 23-HC-001H-1

Page 2 of 8
SUBJECT:

DTC P1B25, P1B76, P1B77, P0A0D

SUBJECT:

Service Procedure:

STUI
Refer to the latest Digital Documentation Policy for requirements.
1.

If vehicle is 13-15MY, go directly to step 7 for Power Relay Assembly Replacement.

2.

Depress the brake pedal and press the Start/Stop button once to activate “EV Ready” mode.
Attach a GDS, and select VIN, BMS menu and DTC. Check for DTC in the BMS menu. Record
the DTC and description. Delete the DTC.
Select Current Data and the following parameters. If the results are not as shown, the power
relay assembly (PRA) may not be functioning correctly. Go to step 3.

3.

Parameter
BMS Main Relay ON Status

Result
YES

Inverter Capacitor Voltage

200v~310v

Turn off the ignition, open the rear trunk and
open the cover to the safety plug.
!

WARNING

Failure to wear protective gear and perform
this procedure may result in accidental
injury or death.
Follow all safety precautions in the shop
manual:
• Hybrid Motor System > General Safety
Information and Caution
Put on insulating gloves and pull up on the
black tab and pull out the safety plug.
4.

Without depressing the brake pedal, push the Engine Start-Stop button 2 times to power the
cluster.
Attach a GDS and select BMS menu, Current Data and Inverter Capacitor Voltage.
Confirm the Inverter Capacitor Voltage is less than 30V.
• If less than 30V, the system voltage is safe for the technician. Turn OFF the ignition and
disconnect the 12V negative (–) battery cable. Go to step 5.
• If more than 30V, wait until the voltage is less than 30V before performing any repairs.
Turn OFF the ignition and disconnect the 12V negative (–) battery cable. Go to step 5.

TSB #: 23-HC-001H-1

Page 3 of 8
SUBJECT:

DTC P1B25, P1B76, P1B77, P0A0D

SUBJECT:

5.

Use a DVOM to measure the resistance of the
BUS fuse inside the safety switch.
Measure the resistance between the BMS
pins.
Specification: 1Ω or less
BUS
Fuse

If the resistance is:
•
•

Not within specification: Replace the
safety plug and proceed to step 7.

BMS
Pins

Within specification: Go to step 6.

TSB #: 23-HC-001H-1

Page 4 of 8
SUBJECT:

DTC P1B25, P1B76, P1B77, P0A0D

SUBJECT:

6.

Visually inspect the lower part (A) of the safety
plug to see if the fuse is genuine or nongenuine as shown at right.
•

Genuine part (“PEC” Branded): No need
to replace. Reinstall all parts in reverse
order of removal and proceed to step 7.

•

Non-genuine part: Replace the safety
plug, reinstall all parts in reverse order
of removal.

Genuine part

A

Example of a Non-genuine part

A

7.

i

Information

B

The following steps (7 – 13) only apply
for PRA-related DTCs P1B76/P1B77.

B
B

Remove the rear seat.
Refer to the shop manual:
• Body (Interior and Exterior) > Seat &
Power Seat > Rear Seat > Repair
procedures
Remove the 7 screws (B) securing the rear
seat access cover.

B

B

B
B

TSB #: 23-HC-001H-1

Page 5 of 8
SUBJECT:

SUBJECT:

8.

DTC P1B25, P1B76, P1B77, P0A0D

Remove the 5 fasteners (C) and remove the
carpet trim.

D

Refer to the shop manual:
• Body (Interior and Exterior) > Interior >
Trunk Trim > Repair procedures

D

C

C
D

Remove the 4 nuts (D) securing the air duct
and remove the air duct.

C

D

C

C

9.

Remove the nuts and bolts (E) securing the
steel cover and remove the cover for the
power relay assembly (PRA).
E

E

E

TSB #: 23-HC-001H-1

Page 6 of 8
SUBJECT:

DTC P1B25, P1B76, P1B77, P0A0D

SUBJECT:

10.

!

WARNING

The HEV battery may have a charge of
120~150v. Failure to wear insulating gloves
may result in accidental injury or death.

H

Put on leather gloves on top of the insulating
gloves. Wear safety glasses.

G

Remove the negative (–) cable (F) first and
wrap the cable end with insulating tape.
F

Next remove the positive (+) cable (G) and
wrap the end with insulating tape (H).
Tightening Torque:

11.

lb-ft

7.3

lb-in

87

N.m

9.4

i

Information

With the high voltage cables insulated,
you may perform the steps below without
PPE.
Remove the 10mm nut securing the inverter
cables to the power relay assembly (PRA) (I).
Remove the negative (–) inverter cable (J) first,
then the positive (+) cable (K).

K

J

Tightening Torque:
lb-ft

7.3

lb-in

87

N.m

9.4

I

TSB #: 23-HC-001H-1

Page 7 of 8
SUBJECT:

DTC P1B25, P1B76, P1B77, P0A0D

SUBJECT:

12.

Remove the black connector here as well as
the mating connector anchored to the steel tab
to gain access to the nut securing the BMS
ECU.

13.

Loosen the four nuts (L) and tilt the BMS ECU
to the left to provide clearance between it and
the power relay assembly (PRA).

BMS
ECU

L
M

Remove the three mounting nuts (M) and
remove the power relay assembly (PRA).
Install a new PRA following the reverse order
of removal.
Tightening Torque:
lb-ft

7.3

lb-in

87

N.m

9.4

L

14.

Reassemble all parts in the reverse order of disassembly.

15.

Attach a GDS and delete any DTC.

16.

Clear the DTC in the BlueLink system according to instructions in TSB 19-BE-010 (or latest
version).

17.

Drive the vehicle for two key-on/key-off drive cycles.

18.

End of service procedure.

TSB #: 23-HC-001H-1

Page 8 of 8
SUBJECT: