How to replace a engine module

This would vary by year and model. The best thing to do if you suspect you have an ECM failure on your hands is take it in and get it diagnosed. Under the estimator link posted here, you can select for diagnosis of your check engine lights and get a decent idea of what you would be in for. The shops listed on the second link are trusted facilities that have customer best interests in mind. https://repairpal.com/estimator/chevrolet/malibu https://repairpal.com/chevrolet-within-10-miles-of-whitehouse-texas-75791