Code 78 (Coolant Temperature Sensor)

ENGINE TEMPERATURE SENSOR (COOLANT)
Explanation
This trouble code is stored in the case of a short or break occurring at the temperature sensor or on its supply wires. To detect a short to positive or a break, the plausibility of the coolant and the intake air temperature is checked. When this defect is detected the system will use substitute values to continue engine operation.

Troubleshooting
- Check temperature values by means of status monitoring.
- Proceed with displayed scan tool diagnostic instructions where applicable.