C1781: Engine Coolant Temperature Signal Missing/Fault
MediumChassisChassis Electronics
What does C1781 mean?
C1781 is a diagnostic trouble code indicating "Engine Coolant Temperature Signal Missing/Fault". This code relates to your vehicle's chassis electronics and should be diagnosed to determine the root cause. The severity level helps indicate how urgently this should be addressed.
Common causes
- Stuck thermostat (open or closed)
- Low coolant level or coolant leak
- Failed coolant temperature sensor
- Faulty water pump
- Blocked radiator
What should you do?
Schedule a diagnostic appointment at your earliest convenience. The vehicle is generally safe to drive short distances, but the underlying issue should be addressed to prevent it from worsening.
Get a diagnosis for YOUR car
Code C1781 can mean different things depending on your vehicle. TorqueBot gives you a diagnosis specific to your make, model, and year.