Immo - Continental GM 76.1

ljscodex said:

Hi folks.

I need to make immo off on this flash. Can anybody support me?

Manual transmission with ...

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If the original ECU is totally dead due to water damage and you cannot read it (even via JTAG/BDM), then Immo Off on the donor is the way to go.

Please upload the Flash dump from the donor ECU.
Note: Checksum correction will be required after modification.

Thanks for your fast response, flash is already attached on the first post.

ljscodex said:

Thanks for your fast response, flash is already attached on the first post.

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My apologies, I missed the attachment in the first post.

For the Continental 76.1, please ensure that your programmer corrects the checksums when writing the modified file. If the checksum is invalid, the ECU will not communicate.

If you are using KTAG, verify that the plugin supports checksum correction for this specific hardware ID.

You can't remove the immo in a manual gearbox, you have to add it, all the solutions that work are for the automatic gearbox, I know the subject very well

i was able to get original dumps and i wrote it into the donor ecu, but car doest start.

Original:

ECU: 5WY1J19BHW: 10123904AASW: CAO95G40.DATSW Version: J4EG40M1.DR

Donor:
ECU: 5WY1J27AHW: 10123904AASW: CAO95H30.DATSW Version: 48HH30M1.DR

ljscodex said:

i was able to get original dumps and i wrote it into the donor ecu, but car doest start.

Original:...

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If you wrote the full dump (Full Flash + EEPROM area) from the original to the donor and it still doesn't start, it is highly likely that your original read is corrupted (due to the water damage you mentioned) or the checksums were not calculated correctly during the write.

For the Manual transmission with Start Button (PEPS system), "Immo Off" is indeed very difficult or impossible via simple flash modification without causing other issues.

Since cloning failed, your best solution is to adapt the donor using OEM tools:

• Restore the Donor ECU to its original state (or leave it if you can't).
• Use GM SPS (Service Programming System) via Tech2Win, GDS2, or Techline Connect with a J2534/MDI interface.
• Select "Replace Engine Control Module".
• Follow the procedure to program the VIN and software.
• Perform the Immobilizer Learn procedure.

You will need the Security Code (PIN) from the vehicle (BCM) to complete the immobilizer matching. If you don't have the PIN, you can usually read it from the BCM or the Instrument Cluster eeprom.

ljscodex said:

Solved partially. thanks

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Glad to hear you made some progress.

Could you share details on how you managed to get it partially working? Also, what issues remain (DTCs, safe mode, etc.)?

Sharing the solution would be very helpful for others dealing with this specific Continental 76.1 configuration (Manual + Start Button), as it is known to be tricky.