[deyobr]

I believe my ECM is bad. I've got a misfire in 4 and a fuel injector code for the same cylinder along with the open circut fuel system status. I replaced the coil and the injector in 4.

So, I bought a new ECM on ebay from a company that said they'd program it to my VIN. Got the ECM, installed it, and tried the key learn process.

I'm not able to complete the key learning process because of the following issue.

When I turn the key on and then perform the first 10min. wait cycle the security system light never goes out. I don't get the "Starting Disabled - Remove Key" error. Instead, I get the "Security System Failure" error or something like that.

On top of that, when I go to turn the key off after 10min., I can't turn it off or remove it from the ignition.

I have to hook up my old ECM just to get the key out.

Any ideas what's going on here? Is the new ECM bad? Am I doing someting wrong on initial hookup? Has anyone actually replaced the ECM effectively and been able to start the car or reprogram the ECM to the old keys?

 

[jjordan75]

I just went through the same thing. First thing you need to do is send ecm back and go straight to the dealer. Best 957$ I ever spent. Ecm has to be flashed on vehicle

 

[deyobr]

Quick update on this. I probably will do a full write up once I figure it all out.

Turns out that they key relearn wasn't working for a few reasons. I should have known something was wrong but there's very little info out there about this. Here's what I learned.

1. The dash PROBABLY needs to tell you when you attempt the relearn procedure that "Starting is disabled remove key". I think that is the computer telling you that it doesn't recognize the key. If it doesn't say that, I doubt you'll get it to work. The whole point is that they needs to be foreign to the ECM so that it can be learned. I sat for well over 10 min. waiting for the security light to go off with no luck until I figured out the below items.
2. I think you need to do it with a new key. I finally ordered a new key after the ECM supplier mentioned that my old key might be too warn to work. I don't think it was, but the moment I put the new key in, I got the warning, finalized the relearn process and she fired right up. Unfortunately, I had a misfire still. This time it was in a new cylindar. My guess is the reman ECM was bad with the same problem.
3. The ECM has to be grounded. I did so much testing and switching that I tried to shortcut the swapping and it won't work without the ground.
4. At least on my CTS, to get the relearn process to work, the key has to go to position 0 to sit for a few seconds between the 10min. "on" cycles. The reason I'm pointing this out is because my key got locked into the ignition every time I tried the process so I had to use the manual release under the steering column to get it to position 0 each time. Some have said this is due to a bad battery. I can confirm that is not the case. I had my old battery on the charger when doing the work and just replaced it with a new one today and had to do the same.
5. I think every new ECM has to have a new key associated with it. I have two dud ECMs now and I have a third I'm trying to test, but I can't get it to a state where it will learn either of my two keys. I think this might because those keys are associated with the other ECMs somewhere onboard the car. I could be entirely wrong here and the evidence is pointing to something I'm missing, but I can't get this third ECM to learn either of my existing keys and the only thing that has changed is that they are both associated with other ECMs.

So, I'm ording new keys. That is my next step. Then I'm going to call the supplier and see if I can get another new ECM. I'm 95% positive that the ECM is the issue, I just can't stand to put a new one in. I could spend a lot of time and money on new keys to get a $300 one from ebay working vs. going to the dealer.

 

[DLdiamond]

Quick update on this. I probably will do a full write up once I figure it all out.

Turns out that they key relearn wasn't working for a few reasons. I should have known something was wrong but there's very little info out there about this. Here's what I learned.

1. The dash PROBABLY needs to tell you when you attempt the relearn procedure that "Starting is disabled remove key". I think that is the computer telling you that it doesn't recognize the key. If it doesn't say that, I doubt you'll get it to work. The whole point is that they needs to be foreign to the ECM so that it can be learned. I sat for well over 10 min. waiting for the security light to go off with no luck until I figured out the below items.
2. I think you need to do it with a new key. I finally ordered a new key after the ECM supplier mentioned that my old key might be too warn to work. I don't think it was, but the moment I put the new key in, I got the warning, finalized the relearn process and she fired right up. Unfortunately, I had a misfire still. This time it was in a new cylindar. My guess is the reman ECM was bad with the same problem.
3. The ECM has to be grounded. I did so much testing and switching that I tried to shortcut the swapping and it won't work without the ground.
4. At least on my CTS, to get the relearn process to work, the key has to go to position 0 to sit for a few seconds between the 10min. "on" cycles. The reason I'm pointing this out is because my key got locked into the ignition every time I tried the process so I had to use the manual release under the steering column to get it to position 0 each time. Some have said this is due to a bad battery. I can confirm that is not the case. I had my old battery on the charger when doing the work and just replaced it with a new one today and had to do the same.
5. I think every new ECM has to have a new key associated with it. I have two dud ECMs now and I have a third I'm trying to test, but I can't get it to a state where it will learn either of my two keys. I think this might because those keys are associated with the other ECMs somewhere onboard the car. I could be entirely wrong here and the evidence is pointing to something I'm missing, but I can't get this third ECM to learn either of my existing keys and the only thing that has changed is that they are both associated with other ECMs.

So, I'm ording new keys. That is my next step. Then I'm going to call the supplier and see if I can get another new ECM. I'm 95% positive that the ECM is the issue, I just can't stand to put a new one in. I could spend a lot of time and money on new keys to get a $300 one from ebay working vs. going to the dealer.

Did you ever figure this issue out what’s it that You had to fresh cut a new key for the ECM ?