ECU Flash Reprogramming With Security Signature
Operation Procedure (continued)

3. Click the appropriate calibration ID and reprogram the vehicle’s ECU with Techstream.
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 10.

B. Click Open to load the calibration
file information.

Figure 11.

NOTE
Techstream 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.

© 2022 Lexus, a division of Toyota Motor Sales, USA

L-SB-0036-22

August 15, 2022

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ECU Flash Reprogramming With Security Signature
Operation Procedure (continued)
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 11.8V during reprogramming. Confirm battery
voltage is higher than 11.8V 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 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.

C. Click Next to start the calibration
update process.

Figure 12.

© 2022 Lexus, a division of Toyota Motor Sales, USA

L-SB-0036-22

August 15, 2022

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ECU Flash Reprogramming With Security Signature
Operation Procedure (continued)

D. Confirm the following:
 PC is connected to VIM.
 VIM is connected to DLC3 connector.
 Ignition is ON and engine is OFF or READY OFF (hybrid vehicles).
Then, click Next.
Figure 13. Using Techstream 2.0 or Techstream Lite

1

1

Select Correct Device Tool (“Mongoose MFC,” “MongoosePro MFC,” or “MongoosePro MFC2” [Green])

© 2022 Lexus, a division of Toyota Motor Sales, USA

L-SB-0036-22

August 15, 2022

ECU Flash Reprogramming With Security Signature
Operation Procedure (continued)

E. Verify 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.
 Each calibration file may contain
up to three separate calibrations.
 Figure 15 shows an example of
the update procedure for a
two-processor ECU.

F. Turn ignition OFF, then click Next.

Figure 15.

© 2022 Lexus, a division of Toyota Motor Sales, USA

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ECU Flash Reprogramming With Security Signature
Operation Procedure (continued)

G. Confirm the following:

Figure 16.

 PC is connected to VIM.
 Ignition is ON and engine is OFF or
READY OFF (hybrid vehicles).
 Hood is open.
 ALL accessories are OFF.
 Battery voltage is above 11.8V.
NOTICE
Verify the vehicle is connected to a
battery charger before continuing.
If battery voltage falls below 11.8V,
ECU damage may occur.

Then, click Start.
NOTE
If the key cycle is NOT done properly, reprogramming will stop at 10% and Cal 1 will fail to load.

© 2022 Lexus, a division of Toyota Motor Sales, USA

L-SB-0036-22

August 15, 2022

Page 13 of 18

ECU Flash Reprogramming With Security Signature
Operation Procedure (continued)

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

I.

Input TIS login credentials and select Login.
Figure 18.

© 2022 Lexus, a division of Toyota Motor Sales, USA

L-SB-0036-22

August 15, 2022

ECU Flash Reprogramming With Security Signature
Operation Procedure (continued)

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

K. Select Send.
Figure 20.

L. Copy the Signature from TIS.
Figure 21.

© 2022 Lexus, a division of Toyota Motor Sales, USA

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ECU Flash Reprogramming With Security Signature
Operation Procedure (continued)

M. Paste the Signature into Techstream and select Next.
Figure 22.

Do NOT disturb the vehicle during
flash reprogramming.

Figure 23.

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).

Does the vehicle require ONLY ONE calibration update?


YES — Go to substep Q.



NO — If the vehicle requires a SECOND calibration update, continue as follows:
 For serial communication vehicles, continue to substep N.
 For CAN communication vehicles, go to substep P.

© 2022 Lexus, a division of Toyota Motor Sales, USA

L-SB-0036-22

August 15, 2022

ECU Flash Reprogramming With Security Signature
Operation Procedure (continued)

N. When Cal 1 completes the update
process, turn the ignition OFF for a
minimum of 10 seconds, then
click Next.

Figure 24.

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

Figure 25.

NOTE
If the key cycle is NOT done properly,
reprogramming will stop at 10% and Cal 2
will fail to load.

P. Do NOT disturb the vehicle during
flash reprogramming.

Figure 26.

© 2022 Lexus, a division of Toyota Motor Sales, USA

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ECU Flash Reprogramming With Security Signature
Operation Procedure (continued)

Q. Turn the ignition OFF for a minimum of
10 seconds, then click Next.

Figure 27.

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

Figure 28.

S. Confirm ALL calibrations were updated
as specified in this Service Bulletin,
then click Finish.

Figure 29.

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 Techstream. 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.

© 2022 Lexus, a division of Toyota Motor Sales, USA

L-SB-0036-22

August 15, 2022

Page 18 of 18

ECU Flash Reprogramming With Security Signature
Operation Procedure (continued)

4. Attach the Authorized Modifications Label.
A. Using a permanent marker or ballpoint pen, complete the Authorized Modifications Label
and attach it to the vehicle. The Authorized Modifications Label is available through the
MDC, P/N 00451-00001-LBL.
Figure 30.

1

Replacement ECU Part Number

4

Date Completed

2

Calibration ID(s)

5

Service Bulletin or Campaign Number

3

Dealer Code

B. Attach the Authorized Modifications Label under the hood in the location determined by
the specific Service Bulletin or Campaign.
NOTE
Wait 60 – 90 seconds for ink to set BEFORE handling.

© 2022 Lexus, a division of Toyota Motor Sales, USA