Chevrolet Volt check engine light with 'engine not available' message, dealer recommends TCM/solenoid assembly replacement on Chevrolet Volt

Some Chevrolet Volt owners report experiencing significant issues when the check engine light is accompanied by the 'engine not available' message, indicating potential malfunctions in the Transmission Control Module (TCM) or solenoid assembly. This message often signals a problem with the vehicle's powertrain, particularly the engine, which may prevent the car from switching to gas mode. Drivers have noted symptoms such as reduced propulsion power, engine shutdown, and inaccurate gas gauge readings. While some users have found temporary relief by resetting the check engine light with an OBD scanner, the issue frequently reoccurs after a short distance. Additionally, there are instances where the software fails to detect adequate energy in the high-voltage battery, contributing to the 'engine not available' message. Standard troubleshooting may involve checking the starter or manually turning the engine, but if a dealer recommends replacing the TCM or solenoid assembly, it is crucial to follow their advice to resolve the underlying issues and ensure the vehicle's powertrain functions properly.