P2185 indicates the powertrain control module detects a voltage signal from the second engine coolant temperature sensor that is higher than the normal operating range. This usually suggests an electrical open circuit or a sensor reading implausibly cold temperatures compared to other inputs. It affects cooling fan operation and transmission shifting rather than primary fuel mixture.
The internal resistance of the sensor has become too high or open, sending a maximum voltage signal to the computer.
An open circuit or break in the wire leading to the sensor prevents proper signal transmission.
If the coolant level drops below the sensor, it measures air temperature instead of liquid temperature.
Oxidation or debris at the sensor plug increases resistance in the signal circuit.
A thermostat stuck open may cause coolant temperatures to remain lower than expected operating ranges.
A malfunction within the control module itself is possible but statistically very rare compared to sensor issues.
The definition is universal; the diagnostics are engine-specific. Open your vehicle for the codes documented for it:
Not always; Sensor 2 often manages cooling fans or transmission temps, while Sensor 1 typically handles fuel mixture and gauge data.
Short trips are usually safe, but prolonged driving risks overheating or transmission damage due to incorrect fan operation.
No, PCM failure is extremely rare for this code; replace the sensor and check wiring first.
Yes, if the coolant level drops below the sensor, it may read air temperature instead of liquid temperature.