Replacement ECM for Cruze Sonic Trax  I will need a picture of the back of your ECM and your V.I.N. from your car. You keep your old ECM no core charge required.  You ask why did I add replacement ECMs to the website? Well this was a simple decision to make. I diagnose so many cars I have seen a few to many cars after months of diagnosing end up having a bad ECM. Then after realizing the ECM is a culprit my customer has no way of getting the ECM fixed where they live or it is super expensive so I decided to help out even more and give the option to have an ECM literally delivered to your door. These will come programed to your car ready to install. BUT keep in mind your car comes from the factory with anti theft. In certain situations you may get an engine code or a car that will not start because of anti theft becoming active. This is due to the fact that modern cars try to prevent theft. This is what it was designed for. If that happens I listed the symptoms below and you can perform an anti theft relearn Match your ECM/PCM service number before purchasing. If you have an issue with anti theft here are some of the symptoms. The ECM may need a security key relearn, and may need crankshaft variation relearn (code P0315). You will need a scan tool capable of doing this relearn. The vehicle may or may not start once the computer is installed.  If the vehicle does not start an anti theft password relearn procedure will have to be done.  Also, the vehicle may run for a period of time (weeks or months) and then will not start and may set a code P0633.  If this occurs the following procedure will have to be done so that the security password will be learned by the replacement ECM.  To avoid any inconvenience it is best to do this procedure at the time that you install the replacement ECM.  This requires a programming tool (J2534 interface tool or equivalent) and a subscription to acdelcotds.com  (cost to program one vehicle is $40.00)  A properly equipped auto repair shop, dealer or locksmith can do this procedure. Common ECM part numbers are: GM 12656958, GM 12668866, GM 12616532, GM 12642927, GM 12643636, GM 12677677, GM 12692865, GM 12642100, GM 12672502, GM 12669749, MT12647241, GM 12669908, GM 12668885, GM 12696201, GM 12669329, GM 12692200, GM 12662593, GM 12655499, GM 12692812, GM 12644081, GM 12692812, GM 12676591, GM 12678971, GM 12680325, GM 12680325, GM 12669325, GM 12642927, GM 12655586, GM 12640852