2008 Chevy Impala P0116 Fault: Engine Hot / AC Off After Starter Replacement
Hi, I'm hoping for some help with my 2008 Chevrolet Impala. After a recent starter installation, I started seeing the 'Engine Hot' and 'AC OFF' warning messages on the dashboard. When I scanned the vehicle, the diagnostic code P0116 appeared. I've already replaced the thermostat, coolant temperature sensor (ECT), and their connectors, but the issue persists. The engine still shows high temperatures and AC is not functioning properly. Could this be related to a faulty sensor reading or an electrical connection issue? I'm looking for guidance on how to diagnose further — especially regarding the ECT sensor voltage and potential underlying causes like intake air temperature (IAT) or block heater usage.
Remote starters can sometimes cause issues. You've already replaced the ECT sensor and connector — next step is to use an OBD2 scanner to monitor live sensor data, including intake air temperature (IAT). Please check the voltage at the ECT sensor's yellow wire (typically 5V reference or signal). While unlikely, ensure you're not operating without a block heater, especially in cold weather conditions, as this could affect engine temperature readings.