Possible Causes of Ford P1285 Code
- Engine overheating
- Insufficient coolant level
- Cylinder Head Temperature (CHT) sensor failure
- Damaged Cylinder Head Temperature sensor wiring (open or short circuit)
- Poor electrical connection in the Cylinder Head Temperature sensor circuit
How to Fix Ford P1285 Code?
- Review the possible causes listed above.
- Visually inspect the electrical wiring and related connectors.
- Check the condition of components for possible damage.
- Look for broken, bent, pushed-in, or corroded connector pins.
Technical Notes on Ford P1285 Code
This code indicates that engine overheating has been detected by the Cylinder Head Temperature sensor.
Possible Symptoms of Ford P1285 Code
- Illumination of the check engine light (or “Service Engine Soon” warning light)
Meaning of Ford P1285 Code
The Cylinder Head Temperature (CHT) sensor is a thermistor whose resistance changes with temperature. As temperature increases, resistance decreases, and vice versa. This variation affects the voltage across the sensor, allowing the Powertrain Control Module (PCM) to assess engine temperature.
Installed directly in the aluminum cylinder head, the CHT sensor measures metal temperature, thereby estimating coolant temperature. When overheating is detected, the PCM activates an emergency cooling strategy to limit the risk of damage. Loss or low level of coolant can lead to overheating, damaging critical engine components.
Using the CHT sensor and the backup cooling strategy, the PCM enables air cooling of the engine to prevent irreversible damage. This Diagnostic Trouble Code (DTC) therefore indicates an overheating problem detected by the Cylinder Head Temperature sensor.