Exact procedure for locking VCM/TCM for GM Gen III & IV V8 powertrains?

[turboLS2]

Do I always have to write entire or can I write cal only then tunerlock afterwards? What is the difference between the PCM's as far as procedure? I have the latest beta version already. Please be specific

[Bill@HPTuners]

As explained in our help file

Lock/Unlock your tune
This feature allows the VCM to be "locked" such that others may not access the VCM's contents. Once locked, the VCM will only be able to be unlocked by the VCM Suite software that locked the VCM.

NOTE: HPTuners is not responsible for the use of this feature by tuners. Tuners should advise customers that their VCM will be locked if this is the tuners business policy. Tuners should have an unlocking policy and advise customers the conditions on which their VCM will be unlocked if the circumstance arises.

TunerLock locking procedure:

1. Open the file you want to TunerLock in VCM Editor
2. Open up the Calibration Details window.
3. Press "TunerLock VCM" icon, the status will reflect the new TunerLock status.
4. Select "Flash->Write Entire VCM" or "Flash->Rewrite VIN/Tunerlock/VATS" (note this is not a risk free operation, frying the VCM is possible on PCM's when using this feature). See note below for E38 ECM's.
5. VCM will be reflashed...
6. Wait 15 secs for VCM to reset
7. Switch ignition OFF for 20 secs to allow VCM to save the changes
8. Switch ignition ON for 20 secs to verify
9. Switch ignition OFF for 20 secs
10. Engine should start and run normally

Once the VCM is locked, the VCM Editor program will require two attempts to unlock the VCM (it defaults to try the standard procedure first).

Once the VCM is TunerLocked, if additional tuning is required, the normal (and safe) "Write Calibration Only" function should be used.

To unlock the VCM, use the above procedure but press the "Unlock VCM" button instead.

E38 ECM's: You MUST use the "Rewrite VIN/Tunerlock/VATS" option at Step 4. for the TunerLock feature to be successfully programmed. Write Entire will not set the TunerLock.

NOTE: You MUST use the "Rewrite Entire VCM" or "Rewrite VIN/Tunerlock/VATS" option within the Flash Menu for the TunerLock feature to be successfully programmed. It is recommended that you only use the "Rewrite Entire VCM" or "Rewrite VIN/Tunerlock/VATS" option when performing these functions (they only need to be done once). After the VCM has been TunerLocked, if additional writing is required, the normal (and safe) "Write Calibration Only" function should be used.

[turboLS2]

What is the statistical probability that the PCM will get fried if there is a good uninterrupted connection and sufficient power during the entire write?

[Bill@HPTuners]

0-<1%

[turboLS2]

So when you are locking a C6 VCM - when it says to cycle the ignition off, then on, and then off one more time - are you only turning on "accessory mode" where the yellow light is on. Then turning off again where the red light shows a second time?

Do any of the C6's have E38 ECM's?

[turboLS2]

Hello?

[Bill@HPTuners]

Not sure how corvettes work(I've never tuned one), maybe someone else with more experience can suggest how their key position works.

[ScarabEpic22]

Id suggest going to ON/RUN, so everything powers up. On some vehicles ACC mode will not power the ECM/TCM so you cant communicate with it.