Technical Service Bulletin

SUBJECT:

GROUP
AUTOMATIC
TRANSMISSION

NUMBER

DATE

MODEL

SEPTEMBER, 2020

20-AT-020H

SONATA (LFa)
SONATA (DN8)
SANTA FE (TMa)
PALISADE (LX2)

AUTOMATIC TRANSMISSION OIL PRESSURE DATA TRANSFER –
GDS MOBILE (8-SPEED FWD TRANSMISSION)

This TSB supersedes TSB 18-AT-015 to add additional models.
DESCRIPTION:
This bulletin provides a procedure to transfer pressure data to the TCU using GDS Mobile. This
procedure is necessary to reduce the transmission learning time and improve the shift quality.
 After replacing an automatic transmission: Input the data into the TCU using the GDS.
 After replacing a PCM (ECU/TCU): Back up the oil pressure data from the old TCU into the
GDS and then transfer the data to the new TCU.

NOTICE
Before installing the transmission, the technician should: (1) Use GDS to transfer the
pressure characteristics to the TCU or (2) Take a photo of the tag or (3) Record all digits
on the tag. The pressure characteristics tag is difficult to read after installation.
The oil pressure characteristics bar code location under the air cleaner is shown below.

Serial number

APPLICABLE VEHICLES:
2018~19
2020~
2019~
2020~

Sonata (LFa) 2.0T
Sonata (DN8) 1.6T/2.5L
Santa Fe (TMa) 2.0T/2.4L
Palisade (LX2) 3.8L

Warranty Information: Normal warranty applies.
NOTE: Labor operation for automatic transmission or PCM (ECU/TCU) replacement includes the time
for data transfer.
Circulate To: Service Manager, Warranty Manager, Service Advisors, Technicians, Fleet Repair

SUBJECT:

AUTOMATIC TRANSMISSION OIL PRESSURE DATA TRANSFER

I. DATA INPUT – AFTER REPLACING AUTOMATIC TRANSMISSION
Oil pressure data input procedure using GDS Mobile
1. From the GDS Mobile home screen, select S/W
Management, Automatic Transaxle and Oil
pressure characteristics Input (A/T
Replacement). Select OK.
Select OK and follow the prompts.

2. Select OK and use the QR Reader to read the
barcode tag on the transmission. Select OK and
follow the prompts.
The GDS will transfer the data to the TCU.
If the QR Reader did not successfully transfer the
data, select SERIAL INPUT and go to Step 3.

TSB #: 20-AT-020H

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SUBJECT:

AUTOMATIC TRANSMISSION OIL PRESSURE DATA TRANSFER

3. If the QR Reader did not successfully read the barcode, manually input the transaxle serial
number (12 digits) and select Done. If the GDS fails to input the data, manually input the
complete pressure characteristics data. Select OK.
The GDS will confirm the oil pressure characteristics were input into the TCU. Select OK.

4. Check for DTC and delete any DTC.
5. Reset the automatic transmission adaptive
values using GDS, S/W Management,
Automatic Transaxle and Resetting Auto T/A
Values. Follow the prompts on the GDS.

TSB #: 20-AT-020H

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SUBJECT:

II

AUTOMATIC TRANSMISSION OIL PRESSURE DATA TRANSFER

DATA INPUT - AFTER REPLACING OR EXCHANGING A PCM (ECU/TCU)
Oil pressure data backup and input procedure using GDS Mobile:

NOTICE
If the PCM has been replaced and the oil pressure data has not been input to the new
TCM, the shift position indicator lamps on the instrument cluster or shift lever will blink
continuously with the ignition on and the engine off.
1. From the GDS Mobile home screen, select S/W
Management, Automatic Transaxle and Oil
Pressure Characteristics BackUp & Input
(TCU Replacement).
Select OK and follow the prompts.

2. The GDS will prompt you to backup the pressure
characteristics to the GDS. Select Backup.

TSB #: 20-AT-020H

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SUBJECT:

AUTOMATIC TRANSMISSION OIL PRESSURE DATA TRANSFER

NOTICE
If the GDS cannot communicate with the old TCU, you must locate the oil pressure
characteristics tag under the air cleaner and manually input the values into the GDS.

3. The GDS will prompt you to back up to the Scan
Tool. Select OK.
The GDS will confirm the oil pressure
characteristics of the old TCU was backed up.
Select OK.
Turn the ignition off and install the new PCM
(ECU/TCU).

4. From the GDS Mobile home screen, select S/W
Management, Automatic Transaxle and Oil
Pressure Characteristics BackUp & Input
(TCU Replacement). Select OK and follow the
prompts.
Select Input.

TSB #: 20-AT-020H

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SUBJECT:

AUTOMATIC TRANSMISSION OIL PRESSURE DATA TRANSFER

5. The GDS will prompt you to input the oil pressure
characteristics to the new TCU. Select OK.
The GDS will confirm the oil pressure
characteristics were input to the new TCU. Select
OK.

6. Check for DTCs and delete any DTCs.
7. Confirm proper operation of the vehicle.

TSB #: 20-AT-020H

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