Immobilizer IV ECU Swapping

From Ross-Tech Wiki

This procedure details how to change the Engine Control Unit (ECU) on VW/Audi/Seat/Skoda vehicles with Immobilizer IV.

Determining VIN (ECU) & IMMO-ID/Challenge

[Select]
[01 - Engine]
[Meas. Blocks - 08]
Select Block 081.
[Go!]
The first 17-digit string is the VIN. The second 14-digit string in the Immo-ID (does not apply for all models).
[Done, Go Back]

On models which do not have an IMMO-ID you need to use the IMMO-Challenge instead.
[Advanced ID - 1A]
See the field IMMO-Challenge for the current value, keep in mind that the challenge changes with every ignition cycle!
[Close Controller, Go Back - 06]


Determining VIN (Instrument Cluster) & IMMO-ID/Challenge

[Select]
[25 - Immobilizer]
[Meas. Blocks - 08]
Select Block 081.
[Go!]
The first 17-digit string is the VIN. The second 14-digit string in the Immo-ID (does not apply for all models).
[Done, Go Back]

On models which do not have an IMMO-ID you need to use the IMMO-Challenge instead.
[Advanced ID - 1A]
See the field IMMO-Challenge for the current value, keep in mind that the challenge changes with every ignition cycle!
[Close Controller, Go Back - 06]


Engine Control Unit (ECU) Swapping (USED ECU)

Prerequisites:

  • The NEW (USED) ECU is already installed in the car.
  • Battery voltage at least 12.0 V.
  • All relevant coding and adaptation values have been transferred from the OLD (ORIGINAL) ECU to the NEW (USED) ECU.
  • Make sure to have BOTH PIN's, from the OLD (ORIGINAL) and the NEW (USED) ECU.


[Select]
[01 - Engine]


[Security Access - 16]
For the following procedure, use the PIN of the NEW (USED) ECU.

  • 4/5-digit PIN
    • The PIN needs to be entered as 5-digit number. For example, if your PIN is 1234, enter 01234.

[Do it!]


  • The instrument cluster now shows Immobilizer Adaptation active, wait until it changes to Immobilizer active - this may take up to 2 Minutes.


[Adaptation - 10]
Enter 050 in "Channel Number".
[Read]
For the following procedure, use the PIN of the OLD (ORIGINAL) ECU.

  • 4/5-digit PIN
    • The PIN needs to be entered as 5-digit number. For example, if your PIN is 1234, enter 01234.

[Test]
Check the 1st measuring value.
[Save]
[Done, Go Back]
[Close Controller, Go Back - 06]


  • Switch OFF the ignition and let the car sit for ~1 minute, then switch ON the ignition again.
  • Verify that the NEW (USED) ECU now shows the VIN (and if supported IMMO-ID) of the vehicle now.
  • The challenge of instrument cluster and ECU never matches, so don't bother checking them.

Engine Control Unit (ECU) Swapping (NEW ECU)

Prerequisites:

  • The NEW ECU is already installed in the car.
  • Battery voltage at least 12.0 V.
  • All relevant coding and adaptation values have been transferred from the OLD (ORIGINAL) ECU to the NEW ECU.
  • Make sure to have the PIN of the CAR.


[Select]
[01 - Engine]
[Adaptation - 10]
Enter 050 in "Channel Number".
[Read]
For the following procedure, use the PIN of the CAR.

  • 4/5-digit PIN
    • The PIN needs to be entered as 5-digit number. For example, if your PIN is 1234, enter 01234.

[Test]
Check the 1st measuring value.
[Save]
[Done, Go Back]
[Close Controller, Go Back - 06]

  • The instrument cluster may now show Immobilizer Adaptation active, wait until it changes to Immobilizer active - this may take up to 2 Minutes.


  • Switch OFF the ignition and let the car sit for ~1 minute, then switch ON the ignition again.
  • Verify that the NEW ECU now shows the VIN (and if supported IMMO-ID) of the vehicle now.
  • The challenge of instrument cluster and ECU never matches, so don't bother checking them.


Special Notes

If Adaptation Channel 050 is not saving when the PIN is confirmed to be correct make sure the WSC/Importer/Equipment numbers are NOT all zeros before clicking Save. If address 25-Immobilizer shows all zero details (Shop #: WSC 00000 000 00000) in the Auto-Scan after failed matching they can be changed on the VCDS program [Options] screen. Any value that is not all zeros or ones should work.