HARNESS AS 3W1570 - Caterpillar

The connection of any electrical equipment and the disconnection of any electrical equipment may cause an explosion hazard which may result in injury or death. Do not connect any electrical equipment or disconnect any electrical equipment in an explosive atmosphere.
Test Step 1. Perform a Check of the Fuel Heater and Related Equipment
If the engine is equipped with a fuel heater, perform a check of the fuel heater and thermostat.Expected Result:There are no problems with the fuel heater or the thermostat.Results:
OK - The fuel heater and the thermostat are OK. Proceed to Test Step 2.
Not OK - A problem was found with the fuel heater or the thermostat.Repair: Repair the problem. Ensure that the repair eliminates the problem.STOPTest Step 2. Inspect the Fuel Return Line for Restrictions
Inspect the fuel return line for restrictions. Check for collapsed fuel lines.Note: A restriction in the return fuel line will decrease fuel flow from the fuel manifold. The decrease in fuel flow will cause the fuel in the fuel manifold to increase in temperature.Expected Result:There are no problems with the fuel return lines.Results:
OK - The fuel return lines are OK. Proceed to Test Step 3.
Not OK - A problem was found with the fuel return lines.Repair: Repair the problem. Ensure that the repair eliminates the problem.STOPTest Step 3. Check the Level of Fuel in the Fuel Tank
Fuel is continuously cycled from the fuel tank through the fuel system back to the fuel tank. The quantity of fuel in the fuel tank may affect fuel temperature. If the quantity of fuel in the fuel tank becomes low, there may be insufficient volume to aid in the dissipation of heat. As a result, the fuel temperature will rise.Expected Result:The fuel level in the fuel tank is OK.Results:
OK - The fuel level in the tank is OK.Repair: Verify that the Caterpillar Electronic Technician (ET) is providing the correct fuel temperature. Check the actual fuel temperature. If the two temperatures are different, check the fuel temperature sensor for proper operation. Refer to the diagnostic functional test Troubleshooting, "Engine Temperature Sensor Open or Short Circuit - Test".STOP
Not OK - The fuel level was low.Repair: Check the fuel in the fuel tank for excessive heat. If necessary, add fuel to aid in dissipating heat from the fuel system. Ensure that the repair eliminates the problem.STOP