Diagnostic Aids

WARNING: This page is about a different car, the 2017 Cadillac ATS. However, it is still accessible from the selected car via links, so may be relevant.

A low engine coolant level could cause the thermostat heater to overheat and set a DTC.
The thermostat has a mechanical fail-safe in case of an electrical condition with the thermostat heater. The mechanical thermostat will open at approximately 97°C (207°F).