This code indicates the vehicle's computer detects a voltage signal from the second engine coolant temperature sensor that is lower than the expected minimum threshold. This condition typically points to an electrical short within the sensor circuit or a failed sensor component rather than an actual temperature measurement. Accurate coolant data is required for fuel mixture and cooling fan control.
The sensor internal circuitry may have shorted, sending a permanently low voltage signal to the computer.
Damage to the signal wire insulation can cause contact with the engine block or chassis ground.
Moisture or oxidation at the sensor plug can disrupt resistance and voltage readings.
Proximity to hot exhaust components often degrades wire insulation over time.
Old or contaminated coolant can alter the electrical properties measured by the sensor.
PCM hardware failure is extremely rare and should only be considered after all external circuits are verified.
Not necessarily, as this code usually indicates an electrical circuit fault rather than actual high coolant temperature.
No, replacing the computer is rarely the fix; the sensor or wiring is almost always the cause.
Short distances are acceptable, but prolonged driving risks engine damage due to improper fuel and fan control.
Multiple sensors allow the computer to monitor different engine zones for precise emissions and thermal management.