U1178 – Invalid or Missing Data For Climate Control

U1178 Possible Symptoms

Engine Light ON (or Service Engine Soon Warning Light)

U1178 Possible Causes

Faulty Heating, Ventilation, and Air-Conditioning (HVAC) Module,Heating, Ventilation, and Air-Conditioning (HVAC) Module harness is open or shorted,Heating, Ventilation, and Air-Conditioning (HVAC) Module circuit poor electrical connection

U1178 Description

The Powertrain Control Module (PCM) monitors the Heating, Ventilation, and Air-Conditioning (HVAC) Module. The PCM sets the OBDII code when the Heating, Ventilation, and Air-Conditioning (HVAC) Module is not to factory specifications.