Possible Cause 1: Incorrect or reversed water valve installation.
1. If the machine is equipped with a water valve control unit, check the water valve to ensure it is installed correctly.
2. Some water valves have arrows indicating the direction of water flow on the side of the valve body. Ensure the arrow points to the line leading to the heating coil.
12.2021 Caterpillar ECM ECU Flash Files Full Set Download
3. If the machine is equipped with a cable-driven water valve, ensure the cable is not tangled around the water valve or frame.
4. If the machine is equipped with an electric water valve, ensure the actuator is securely connected to the water valve.
12.2021 Caterpillar ECM ECU Flash Files Full Set Download
Possible Cause 2: Electrical fault in the control panel.
1. Check the control panel to ensure it receives power after the machine is started.
2. Check to ensure the wiring harness is connected to the control panel.
3. Check the wiring harness for any damage or exposed wires.
4. Check the circuit breaker or fuse to ensure there are no open circuits in the system.
Possible Cause 3: Faulty water valve cable or potentiometer.
1. Determine the type of water valve control device used in the machine.
2. If the water valve is connected by a cable, proceed to step
3. If the machine has a built-in potentiometer, proceed to step 5. 3. Check that the cable is connected to the water valve handle.
4. Check the water valve to ensure it is fully open when the temperature control knob is set to the hottest position.
5. Check that the potentiometer is connected to the wiring harness in the dashboard.
6. Check the water valve to ensure it is fully open when the temperature control knob is set to the hottest position.
