Several days ago,one of my old customers drove his Chevrolet Cruze to my garage and ask to solve the trouble of engine cooling fan running all time.It took technicians to fix the problem,and I will share the progress here.Hope it will be a useful info!
With 37,000 miles
The engine cooling fan running all time,but the temperature of the engine and water tank was not up to the limitation yet.
1. Inspect the wire harness of cooling liquid temperature sensor and cooling fan fuse,both of them were fine.
2. Read out the trouble code by GDS,P0113:Intake Air Temperature Circuit High Input.
3. And read out the stream data,it showed the temperature was -40℃ which was inconsistent with actual temperature around.
4. Detected the intake signal voltage of air flow meter,it displayed 5V(2V is normal).
So technician determined the intake temperature sensor was damaged.After replacing a new air flow meter and clearing the trouble code,tested the car and found the cooling fan worked correctly.
By referring to the GM Cruze maintenance manual,technicians known the sensor resistance trouble of intake temperature or engine cooling liquid temperature may cause undeserved activation of cooling fan.If the ECU active the cooling fan with any require condition and do not set any component or system trouble code,the intake temperature sensor or engine cooling liquid sensor may fail.In this real repair case,technicians did not find the engine cooling liquid sensor trobule,so it most likely intake temperature sensor trouble result in cooling fan worked incorrectly.