I purchased a used ECM for my 13' Grand Sport 6-speed. It's out of a 2010 Silverado. The ECM is an E38 and part # 12633238. I called to verify the part number from my dealer with my vin and that was the part # they gave me. I went through my service manager to have it flashed and his tech said they got the ECM flashed with the files for my vin to run the car, but when the Tech II tool went to finish up and program the security it hangs and said something like "trying to connect to the server". They tried last week and again today, thinking maybe last week the GM server was having issues however it didn't work today either. The guy in the parts department now claims I can only use an ECM out of a corvette. Any idea why that would be? Is there some special security module that only allows Corvette ECM's to work in Corvettes. Am I wrong in thinking that since it's an E38 ECM with the same part number as mine that it should work? Any ideas on how the dealer can get this to take the security calibration or another way to use it? My service manager here is cool with mods, but I'm moving to FL next year so who knows how the service manager would be down there if I have an issue over the next three years for my warranty. I want to keep my stock ECM stock, and use this spare ECM to tune. This way I can just plug my stock ECM back in if I have an issue when I move. The reading I did previously said this should be possible, but it's just not working. They are not getting any error codes when trying to do this with the Tech II tool, it just hangs at the last step. Any help is greatly appreciated.

 

The ECM #12633238 is used on the 2013 Corvette. Were they flashing the ECM out of the car? If so The ECM would then need to be installed back in the car to have the next step performed. The security relearn requires that the ecm, bcm and rcdlr be together.

The parts guy is incorrect telling you it must be originally out of a Corvette.

 

The dealer had the ECM in the car. They said they were able to flash it with my vin to get the info it needs for my car, however when the system gets to the next step for the security part it just hangs on them. While they have been trying this, the ECM is in the car, the car is on ACC power with a battery tender, the Tech II tool is plugged into their computer and my OBDII port, and the keys are in the car. The windows, radio, trunk, lock and unlock all function but the the car will not start. They can't figure out why it keeps hanging on the last step for the security. Their computer goes to load it and then the window just says something to the effect of "trying to connect to the server" and never moves forward. The service manager said if someone knows what to do from there with the Tech II tool he's more than willing to do it. Any ideas?

The only other option he said he could think of was to have a performance shop that deals with them program it so the security is removed so I can easily swap ECM's when needed. That way the factory ECM wouldn't lose it's security with my car. Does anyone know of someone that could do that? That way I can tune it when I decide who/how I want to tune it but retain my factory ECM for easy swap ability. It's too bad GM doesn't have more service managers out there like him that have a passion for cars. If they did, this would be a non-issue.

 

If you program the security out of it I'm sure the push button start will no longer function.

The dealership was attempting to do the 10 minute security relearn. A tech 2 and terminal access was required. You can also try the 30 minute security relearn. This can be done yourself without a tech 2.

1-Press and hold the off/start button for approximately 4 seconds to turn the ignition on (with engine off)

2-observe the security indicator. After approximately 10 minutes the indicator will turn off.

3-Turn off the ignition and wait 5 seconds

4-repeat steps 1-3 two more times for a total of 3 cycles or 30 minutes.

5-start the vehicle ( note- you must turn the ignition off after the third cycle) The vehicle now learns the password on the transition from off to crank.

6- clear any applicable DTC codes with a scan tool.

 

Thank you so much for the info. Any idea why the dealer would have been running into server issue like that for the tech 2? I'll swap out the ecm and give that 30 minute way a try. Will I just have to redo that when I put the factory ecm back for any warranty issues when I move? I really want to retain push start.

 

You should be able to do the same 30 minute relearn when you swap back to the factory installed ECM. This relearn isn't required if the ECM was brand new and hasn't been in any previous vehicle.

No idea why they didn't do the 30 minute relearn back at the dealership. I have no idea why the 10 minute relearn didn't work. Hopefully it's not an issue with the used ECM you bought.

Just a heads up for you. If for example you had a engine failure and then swapped back to the original ECM. The dealership maybe requested by GM to look for a certain type of flag in the ecm. This can tell them if it's been changed recently. I can't confirm this but I've read about it in the past. I'll see if I can find a link for you.

 

Thank you so much. If the weather is nice tomorrow I'll swap the ecm's and give that a shot. If it doesn't work I'll contact the people I bought the ECM about a return since they guarantee their ecm's.

 

Read this before you proceed. You might change your mind......

https://www.corvetteforum.com/forums...-question.html

The dealer might not be able to tell but when the ecm goes back to GM as part of the warranty claim they will have a forensic look at it. Certain "check digits" will be different.

 

Well that sucks. Thanks for the info. Looks like I'll just have to tune the stock one and hope to find a service manager down there that has a passion for cars and won't try to deny warrantee work for unrelated things.

 

Reading through the sandyblogs.com article's I wonder if the C6 is subject to that. The Camaros have a global platform, while I don't think the C6 had it. Definitely worth some more reading.