PLATE AS 5N4478 - Caterpillar

For the most accurate specifications for the sender, see the table “Resistor, Solenoid And Sender Specification”. This table is located in the Electrical System Schematic for the machine that is being serviced.Note: The following procedure does not include the Ultrasonic Fuel Level Sensor.Test Step 1. CHECK THE SENDER
Disconnect the sender from the machine harness.
Measure the resistance between the two contacts of the sender. The following data is the correct approximate resistance: 106-3535 Level Sender Assembly and 134-3033 Fuel Level Sender Empty tank ... 240 to 260 ΩHalf tank ... 97 to 118 ΩFull tank ... 27 to 40 Ω 104-5546 Level Sender Assembly, 115-2086 Fuel Level Sender, 121-3174 Fuel Level Sender, 136-1617 Fuel Level Sender, 137-5156 Fuel Level Sender, 150-2995 Fuel Sender, and 151-1399 Sender Empty tank ... 92 to 98 ΩFull tank ... 0 to 3.5 Ω 9X-4942 Fuel Level Sender Empty tank ... 80 to 85 ΩHalf tank ... 40 to 43 ΩFull tank ... 0 to 2 Ω
Actuate the sender by hand while you are measuring the resistance.
The resistance should change as the sender is actuated through the empty range to the full range. Expected Result:The resistance that is measured is within the specifications.Results:
OK - The resistance for the fuel level sender is correct. Proceed to test step 2.
NOT OK - The resistance for the fuel level sender is NOT correct.Repair: Replace the fuel level sender.STOPTest Step 2. CHECK IF THE DIAGNOSTIC CODE REMAINS
Clean the contacts of the harness connectors.
Reconnect all harness connectors.
Observe the status of the diagnostic code.
Operate the machine.
Observe the status of the diagnostic code. Results:
YES - The diagnostic code is NO longer active. The diagnostic code does not exist at this time. The initial diagnostic code was probably caused by a poor electrical connection and/or a short at one of the harness connectors that was disconnected and then reconnected. Resume normal machine operation.STOP
NO - The diagnostic code has not been corrected. The main display module has failed.Repair: It is unlikely that the main display module has failed. Exit this diagnostic code and perform this diagnostic code again. Replace the main display module if the cause of the diagnostic code is not found. See Testing And Adjusting, "Module - Replace".STOP