GTS+ ECU Flash Reprogramming With Security Signature
Operation Procedure (continued)

D. Available calibration updates are indicated by a Yes in the Calibration Update column.
Click the Yes link in the calibration information section to access the appropriate Service
Bulletin on TIS.
NOTE
 Note ANY DTCs stored in systems that will be flash reprogrammed.
 Clicking the Yes link will automatically launch TIS and perform a calibration search.
Figure 7.

E. Login to TIS.
HINT
If already logged in, skip this step.

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Submitted to NHTSA on 03/07/2025

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GTS+ ECU Flash Reprogramming With Security Signature
Operation Procedure (continued)

F. To review the Service Bulletin and access the calibration file, click the Service Bulletin link
in the Document Title column of the Calibration Search Result portlet.
NOTE
ONLY Toyota certified technicians and other authorized users may access calibration files.
Figure 8.

2. Connect the DCA-8000 battery diagnostic tool.
NOTE
Refer to Vehicle Reprogramming Tips for other approved chargers, located at
TIS – Diagnostics – Reprogramming – Reference Documents.

A. Connect the DCA-8000 battery diagnostic tool to the vehicle and turn it ON.
B. Select Power Supply Mode.
NOTICE
 ECU damage may occur if the correct battery charger and mode setting are NOT used.
 The battery diagnostic tool MUST be used in Power Supply Mode to maintain battery
voltage at 13.5V while flash reprogramming the vehicle.
 For details on how to use the battery diagnostic tool, refer to the
DCA-8000 Instruction Manual located at TIS – Diagnostics – Tools & Equipment –
Battery Diagnostics.

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GTS+ ECU Flash Reprogramming With Security Signature
Operation Procedure (continued)

3. Click the appropriate calibration ID and reprogram the vehicle’s ECU with GTS+.
A. AFTER reviewing the procedures outlined in the selected Service Bulletin, click the
appropriate calibration ID link by matching the vehicle’s current calibration ID to the
Previous Calibration ID in the Calibration Identification Chart.
NOTE
 Calibration files are embedded as live links in the Service Bulletin.
 Some vehicles require special preparation. Review the selected Service Bulletin carefully.
Figure 9.

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GTS+ ECU Flash Reprogramming With Security Signature
Operation Procedure (continued)

B. Click Open to load the calibration file information. If prompted to choose GTS or GTS+,
select GTS+.
NOTE
 GTS+ downloads calibration files as needed to ensure the latest calibration file is used.
 Do NOT save calibrations locally on the hard drive or other media for future use.

Figure 10.

Figure 11.

NOTICE
Errors during the flash reprogramming process can permanently damage the vehicle
ECU. Minimize the risk by following the steps below.
 Battery voltage MUST NOT FALL BELOW 12V during reprogramming. Confirm battery
voltage is higher than 12V but be sure voltage DOES NOT RISE ABOVE 16.0V
during reprogramming.
 Turn OFF ALL vehicle accessories (audio system, A/C, interior lights, DRL, etc.).
 Do NOT add to or significantly change the vehicle’s electrical load
while reprogramming.
 Confirm the hood is open and ensure under-hood temperature does NOT exceed
158°F (70°C ).
 Confirm cable connections between the vehicle and Techstream are secure.
 Do NOT disconnect or turn off Techstream or vehicle ignition during reprogramming.
 Set the parking brake.
 Complete ALL flash calibration updates provided for each ECU.
 If the battery’s State-Of-Charge (SOC) or capacity is in question, test with SST No.
DSS-5000P T (Battery Diagnostic Tool), and follow the DSS-5000 Instruction Manual
located at TIS – Diagnostics – Tools & Equipment – Battery Diagnostics.
 The DCA-8000 battery diagnostic tool MUST be used in Power Supply Mode to
maintain battery voltage at 13.5V while flash reprogramming the vehicle.
For details on how to use the DCA-8000 battery diagnostic tool, refer to the
DCA-8000 Instruction Manual located at TIS – Diagnostics – Tools & Equipment –
Battery Diagnostics.

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Submitted to NHTSA on 03/07/2025

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February 10, 2025

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GTS+ ECU Flash Reprogramming With Security Signature
Operation Procedure (continued)

C. Click Next to start the calibration
update process.

Figure 12.

D. Confirm the following:
 The PC is connected to VIM.
 The VIM is connected to DLC3 connector.
 The Ignition is ON and the engine is OFF or READY-OFF (hybrid vehicles).
Then, click Next.
Figure 13.

1

1

Select the Correct Device Tool (“MongoosePro MFC,” “MongoosePro MFC2,” or
“Mongoose-Plus MFC3” VIM)

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GTS+ ECU Flash Reprogramming With Security Signature
Operation Procedure (continued)

E. Verify the correct current and NEW
calibration information, then click Next.

Figure 14.

NOTICE
 The total number of calibration IDs
in the calibration file corresponds to
the number of reprogrammable
processors in the ECU.
 The figure on the right shows an
example of the update procedure for
a two-processor ECU.

F. Turn the ignition OFF, click Next, and wait
at least 10 seconds before proceeding.

Figure 15.

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GTS+ ECU Flash Reprogramming With Security Signature
Operation Procedure (continued)

G. Turn the Ignition ON (IG ON Ready-OFF
for hybrid vehicles).

Figure 16.

H. Confirm the following:
 The PC is connected to VIM.
 The hood is open.
 ALL accessories are OFF.
 Battery voltage is above 12V.
NOTICE
Verify the vehicle is connected to a
battery charger before continuing. If
battery voltage falls below 12V, ECU
damage may occur.

Then, click Start.
NOTE
If the key cycle is NOT done properly, reprogramming will fail, and an error message will appear
prompting you to restart.

I.

Based on the version of GTS+ being used, please follow the appropriate steps listed below:
 GTS+ software version 2024.03 or newer, go to sub step P.
 GTS+ software version 2024.02 or older, continue to sub step J.

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GTS+ ECU Flash Reprogramming With Security Signature
Operation Procedure (continued)

J. This vehicle is equipped with additional security measures requiring a Signature from TIS.
Select Next to open TIS and retrieve the Signature.
Figure 17.

K. Input TIS login credentials and select Login.
Figure 18.

© 2025 Toyota Motor Sales, USA
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T-SB-0021-25

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GTS+ ECU Flash Reprogramming With Security Signature
Operation Procedure (continued)

L. Input TIS login credentials for secondary authentication and select Login.
Figure 19.

M. Select Send.
Figure 20.

N. Click Copy to Clipboard to copy the signature from TIS.
Figure 21.

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GTS+ ECU Flash Reprogramming With Security Signature
Operation Procedure (continued)

O. Paste the Signature into CUW+ and select Next.
Figure 22.

Figure 23.

P. Select OK to continue.
NOTE
Sub steps P and Q are ONLY required for
GTS+ software version 2024.03 and newer.

© 2025 Toyota Motor Sales, USA
Submitted to NHTSA on 03/07/2025

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GTS+ ECU Flash Reprogramming With Security Signature
Operation Procedure (continued)

Q. Enter your password and select LOG IN
to continue

Figure 24.

R. Do NOT disturb the vehicle during
flash reprogramming.

Figure 25.

NOTE
 ECU flash reprogramming may take
3 – 30 minutes per calibration file.
 Reprogramming time will vary
depending on model and ECU
communication protocol. Vehicles using
CAN communication protocol will
reprogram much faster (2 – 7 minutes).

S. Does the vehicle require only ONE calibration update?
 YES — Go to sub step T.
 NO — If the vehicle requires a SECOND calibration update, continue as follows:
 For serial communication vehicles, continue to sub step T.
 For CAN communication vehicles, go to sub step V.

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Submitted to NHTSA on 03/07/2025

T-SB-0021-25

February 10, 2025

GTS+ ECU Flash Reprogramming With Security Signature
Operation Procedure (continued)

T. When Cal 1 completes the update
process, turn the ignition OFF, click Next,
and wait a MINIMUM of 10 seconds
before proceeding.

Figure 26.

U. Turn the ignition to the ON position,
then click Start.

Figure 27.

NOTE
If the key cycle is NOT done properly,
reprogramming may fail, and an error
message will appear prompting you to
restart Cal 2.

V. Do NOT disturb the vehicle during
flash reprogramming.

Figure 28.

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GTS+ ECU Flash Reprogramming With Security Signature
Operation Procedure (continued)

W. Turn the ignition OFF, click Next, and
wait a MINIMUM of 10 seconds
before proceeding.

Figure 29.

X. Turn the ignition to the ON position, then
click Next.

Figure 30.

Y. Confirm calibrations were updated and
click Finish.

Figure 31.

NOTE
On some models, DTCs may set as a result of reprogramming. If DTCs are present, clear codes and
run the Health Check again. Troubleshoot ANY remaining current, pending, or history codes.
Permanent codes will NOT be cleared using GTS+. Permanent codes do NOT illuminate the MIL and
do NOT require troubleshooting. They will clear during normal driving once the Universal Trip Drive
Pattern is performed.

© 2025 Toyota Motor Sales, USA
Submitted to NHTSA on 03/07/2025