ROD AS 0875640 - Caterpillar

Illustration 1 g03409622
Example of an Ultrasonic Fuel Level Sensor Schematic (D9R)
Illustration 2 g00314973
Fuel Level Sender Schematic (typically used)This diagnostic code is recorded when the main display module reads the signal voltage. The voltage from the sender is too high. The corresponding gauge (fuel level) will indicate an abnormally low fuel level. The following causes could signal this diagnostic code:
The sender has failed.
The ground circuit for the sender in the machine harness is shorted to +battery.
The signal circuit in the machine harness is shorted to +battery.
The signal circuit in the machine harness is open or the sender is disconnected.
The main display module has failed. Display module failure is uncommon.Service Notes: Ensure that the desired code (CID and FMI) is on hold. Ensure that the diagnostic code indicator shows "SERV CODE". The above schematic represents a typical installation of the component. Verify the connector contact and wire numbers by using the Electrical System Schematic for the machine that is being serviced. The below procedure is for troubleshooting the two-wire fuel level sender only.Test Step 1. CHECK THE MAIN DISPLAY MODULE AND THE HARNESS
Turn the disconnect switch and the key start switch to the ON position.
The diagnostic code indicator should show "SERV CODE" for the diagnostic code.
Disconnect the machine harness from the sender that is causing the diagnostic code.
Connect the signal wire 447-PK to the ground wire 201-BK on the machine harness connector.
Observe the diagnostic code indicator.Expected Result:The diagnostic code indicator remains ON.Results:
YES - The diagnostic code indicator remains ON. The harness wiring or the main display module has failed. Proceed to test step 2.
NO - The diagnostic code indicator turns OFF. The sender has failed.Repair: Replace the sender.STOPTest Step 2. CHECK FOR AN OPEN GROUND
Remove the jumper wire between the signal wire 447-PK and the ground wire 201-BK.
Turn the disconnect switch and the key start switch to the OFF position.
Measure the resistance between frame ground and the ground wire for the sender.Expected Result:The resistance is 5 ohms or less.Results:
YES - The resistance is 5 ohms or less. Proceed to test step 3.
NO - The resistance is greater than 5 ohms. The ground wire for the harness is open.Repair: Repair the ground wire or replace the ground wire for the sender.STOPTest Step 3. CHECK THE SIGNAL WIRE FOR THE SENDER
Turn the disconnect switch and the key start switch to the ON position.
Measure the voltage between the frame ground and the signal wire for the sender.Expected Result:The voltage measurement should be within one of the following specifications.Results:
6.0 0.5 DCV - The voltage is 6.0 0.5 DCV. The voltage is correct. Verify that the diagnostic code is still present. Repair: Display module failure is uncommon. Perform this procedure again. Also, recheck if the diagnostic code indicator is illuminated for this diagnostic code. If the cause of the diagnostic code is not found, replacement of the main display module may be needed. Prior to replacing an ECM, contact the Technical Communicator at your dealership for possible consultation with Caterpillar. This consultation may greatly reduce