RENR5042-02 107 Troubleshooting Section When the sensor is immersed in coolant, an internal switch is closed. When the internal switch closes, the signal for the engine coolant level is grounded through the sensor return. The Electronic Control Module (ECM) detects the ground on the input for the engine coolant level. If the signal is not present, an event code is generated. Verify that the coolant level has been programmed to “Enabled” on the configuration screen on the Caterpillar Electronic Technician (ET). If the coolant level is not programmed, Cat ET will display “Unavailable” for the parameter. g01119821 Illustration 32 Schematic of the engine coolant level sensor Test Step 1.
Check the Coolant Level Not OK The coolant is at the proper level. Proceed to Test Step 2. Test Step 2. Inspect the Electrical Connectors and the Wiring Pressurized System: Hot coolant can cause seri- ous burns. To open the cooling system filler cap, stop the engine and wait until the cooling system components are cool. Loosen the cooling system pressure cap slowly in order to relieve the pres- sure. A. Turn the keyswitch to the OFF position. A. Stop the engine. Allow the engine to cool. B. Check the coolant level. Refer to the engine’s Operation and Maintenance Manual for the proper procedure. Expected Result: The coolant level is low. Results: OK – The coolant level is low. Repair:
Add coolant according to the procedure in the Operation and Maintenance Manual. Identify the source of the coolant leak and fix the problem. Verify that the original problem is resolved. STOP.