HOSE-HYDRAULIC 2138708 - Caterpillar

Electronic Control Module (ECM) uses the coolant flow switch at the outlet of the jacket water pump in order to determine if there is coolant flow in the engine. If the ECM determines that no coolant flow is present, the ECM will send a warning via the data link to the monitoring panel. An event will also be logged in the ECM. The event can be viewed with the Caterpillar Electronic Technician (ET). A factory password is required to clear the event with Cat ET.The ECM may modify the operation of the engine in the event of loss of coolant flow. The coolant flow switch is a passive sensor. The switch does not have a power supply.The switch uses a paddle to control the circuit. When there is enough coolant flow to move the paddle, the circuit is closed. When the coolant flow is insufficient, the paddle opens the circuit.The ECM cannot determine if the switch or the associated components have failed. A problem is present when the ECM detects coolant flow and the engine is not running. A problem is present when there is coolant flow that is determined by other means and the ECM does not detect coolant flow.