Chevrolet Sonic no start issue suspected to be ECM failure after battery replacement on Chevrolet Sonic

Some Chevrolet Sonic owners report experiencing no-start issues after replacing the battery, raising concerns about potential ECM failure. These owners note that a faulty ECM can lead to various battery problems, such as draining the battery and causing electrical malfunctions. Additionally, the presence of the U0100 diagnostic trouble code may indicate a loss of communication between the ECM/PCM and other control modules, suggesting ECM-related issues. Since the ECM is crucial for managing essential vehicle functions, a loss of battery power can adversely affect it, potentially resulting in stalling conditions or emission monitor resets. Owners are advised to check the ECM's wiring for damage or loose connections, as these can mimic ECM failure. Corroded wires in the wiring harness are a common cause of ECM issues, which can often be resolved by replacing the affected wires. Symptoms like no power when the key is inserted may indicate problems with the ECM-power relay. Furthermore, it is important for owners to consider reprogramming or resetting the vehicle's computers, including the ECM, after a battery replacement to ensure everything functions correctly.