2733

Common Causes

• Coolant tank level low or pickup strainer and pipe clogged so the pump delivers nothing
• Coolant flow sensor stuck, fouled with chips or failed so it never reports real flow
• Coolant supply sensor switch set to the wrong position
• Flow present with output off (codes 5-7) pointing to a stuck valve or miswired sensor

Troubleshooting Steps

1. 1Read the code number shown with the alarm: code None = Coolant flow sensor did not turn on within the flow monitor time (supply sensor types); code 1 = Coolant 1 commanded but 1st/2nd coolant 1 flow never arrived within the set watch time; code 2 = Coolant 2 commanded but 1st/2nd coolant 2 flow never arrived within the set watch time; code 3 = Coolant 3 commanded but 1st/2nd coolant 3 flow never arrived within the set watch time; code 4 = Coolant 4 flow absent beyond the coolant 4 flow alarm monitor time; code 5 = Coolant 1 flow switch stayed on longer than allowed while coolant 1 outputs were off; code 6 = Coolant 2 flow switch stayed on longer than allowed while coolant 2 outputs were off; code 7 = Coolant 3 flow switch stayed on longer than allowed while coolant 3 outputs were off
2. 2Read the code to identify which coolant circuit failed (1-4, 13-18, 22-24 no-flow on demand; 5-7 flow when off; 8-12, 19-21 turret oil mist, turret, high-pressure or chip coolant sensors).
3. 3Check the coolant tank level and fill it, then remove and clean the pump suction strainer and the delivery pipe for the reported circuit.
4. 4Run the coolant output in manual and watch the actual flow at the nozzle while watching the flow sensor input on the I/O screen to see if the sensor tracks real flow.
5. 5If flow is present but the sensor never turns on, clean or replace the flow sensor and confirm the supply sensor switch is set to the correct position.
6. 6For codes 5-7 (flow detected with output off), check for a stuck open coolant valve or a sensor wired to the wrong input before replacing the sensor.