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I haven't done an immo relearn on my car. It's on my to-do list for the bench setup if I ever get the rest of the modules wired up.

Having trouble resting the Immo on a used pcm, and used tcm the brand new virgin e78 excepted a new Immo code after unlocking using mode 27, 67, I sent AE 7E 80 xx xx xx xx
Were x is old pin ( in this case 000000 = 30 30 30 30 in ASCII because it’s brand new)
Then wait 12 min and sent AE 7E 40 yy yy yy yy
Were y is the new pin it worked
Revived response EE 7E

But this doesn’t work on h the used bcm? Way do I need a bcm on the data bus? Do I need to reset mec ignition count to 254 first? The new e78 says mec is 253.

Tried to reset mec to find current mec
Send 1A A0
Receive 5A FA FA = 250

Send 3B A0 00 to set to zero why would we want this??

Tried to send
3B A0 FF
Get 7F 31 back no good
Unlock first with 27, 67
Send 3B A0 FF

Get 7F 31 back no good

Guess this e78 is scrap? Can’t have immmo changed?

I've never had a newer ecm accept the immo pin on the bench, only after it is connected to the vehicle. I'm guessing because the BCM is not on the network. As far as the MEC, some ecm software will never allow it to be changed after it is set to zero. I haven't dug into an e78 yet so I'm not sure on this one.

what was the response when you sent the correct IMMO pin to unlock it?

gmtech825 wrote:I've never had a newer ecm accept the immo pin on the bench, only after it is connected to the vehicle. I'm guessing because the BCM is not on the network. As far as the MEC, some ecm software will never allow it to be changed after it is set to zero. I haven't dug into an e78 yet so I'm not sure on this one.

what was the response when you sent the correct IMMO pin to unlock it?

Put bcm on bench as well and it allowed me to change it! Not sure what changing the Immo code does? Sine it still won’t start unless I Remove vats. How to learn the environment variable?

Were in the bcm eeprom is the environment variable stored? Maybe I can change my trax bcm environment variable to match the customer bcm one then learn is Immo environment in my trax?

The security PIN is only to allow you to get into a module to make further security changes. It's got nothing to do with actually starting the car. The only reason to sync it up to the car is so SPS utilities work correctly.

Immobilizer and environment ID are two separate things. Immobilizer is for ECM and BCM to agree on starting the car, and the relearn is done with the SPS type 4 app. Environment ID is a scam for GM to sell more modules. Err, I mean, prevent module theft. :p You have to have a valid immo and a certain minimum number of matching env IDs for the car to start. You should be able to do an env relearn by unlocking the module with the PIN, waiting out the security timer, and the letting it passively relearn env that's being broadcast by the BCM on the data bus. That's what worked for me when I swapped a 2019 cluster into my 2017 Corvette.

As far as I know, the ECM doesn't participate in the env scheme. Just the immo scheme. I don't believe the TCM plays with either one.

Hopefully you just need to run the immo type 4 at this point.

I can try that do you have the type 4 Immo for dps? Could you share that?

I have the 2018 Colorado bcm and pin for both pcm and bcm

This is a log if a successful type 4 IMMO pc learn in vehicle makes you wait 12 minutes then open drivers door cycle of igntion wait 30seconds, repeat, then finally programmed?

I think 1A A0 puts the module intolerant mode after timer and after entering Immo pin code. Then successful reposnse is 5A A0. ?

04colyZQ8 wrote:I think 1A A0 puts the module intolerant mode after timer and after entering Immo pin code. Then successful reposnse is 5A A0. ?

1A A0 just polls for the MEC DID value. 5A A0 is the response followed by the MEC value

Correct on that then I don’t see anything actually enabling the Immo environment variable?

Maybe key on 12 min without scan tool would also work? Although the key is sent for Immo pin and timmer count down messages sent.

Don’t think it’s easy write this one for bench learn with just pcm and bcm.

Unless one could hack the type 4 file to not look at other modules! Still won’t be able to easily simulate drivers door being opened lol