TUBE ASSY 9N8700 - Caterpillar

Table 1
Diagnostic Codes Table for the DEF Tank Sensor
J1939 Code CDL Code Code Description
(code descriptions may vary) Comments
1761-3 3130-3 Aftertreatment 1 Diesel Exhaust Fluid Tank Level : Voltage Above Normal The ECM detects signal voltage that is not in the acceptable range.
The code is logged.
1761-4 3130-4 Aftertreatment 1 Diesel Exhaust Fluid Tank Level : Voltage Below Normal The ECM detects signal voltage that is not in the acceptable range.
The code is logged.
3031-3 3134-3 Aftertreatment 1 Diesel Exhaust Fluid Tank Temperature : Voltage Above Normal The ECM detects signal voltage that is not in the acceptable range.
The code is logged.
3031-4 3134-4 Aftertreatment 1 Diesel Exhaust Fluid Tank Temperature : Voltage Below Normal The ECM detects signal voltage that is not in the acceptable range.
The code is logged. The 5 VDC signal for the Diesel Exhaust Fluid (DEF) tank level sensor is routed to terminal 1 of the tank header unit. The 5 VDC signal for the DEF tank temperature sensor is routed to terminal 3 of the tank header unit. The sensor return is shared and is routed to terminal 2 of the tank header unit. The ECM provides short circuit protection for the internal power supply. A short circuit to the battery will not damage the internal power supply.Note: The tank header unit houses the DEF tank temperature and the DEF tank level sensors. The sensors are not serviceable individually.
Illustration 1 g03811036
Schematic diagram for the DEF tank header
Illustration 2 g03811042
(1) DEF level signal
(2) Sensor return
(3) DEF temperature signal Complete the procedure in the order in which the steps are listed.
Table 2
Troubleshooting Test Steps Values Results
1. Check for Diagnostic Codes
A. Establish communication between the electronic service tool and the DEF Control Unit (DCU) . Refer to Troubleshooting, "Electronic Service Tools", if necessary.
B. Turn the keyswitch to the ON position.
C. Check for "-3" or " -4" active or logged codes.
Diagnostic code
Result: A -3 diagnostic code is active.
Proceed to Test Step 2.
Result: A -4 diagnostic code is active.
Proceed to Test Step 3.
2. Create a Short at the Sensor Connector
A. Verify that the harness connector is free of debris, free of corrosion and securely connected.
B. Install a jumper wire between the appropriate signal and return wire at the sensor connector in order to create a short. Refer to Illustration 2.
C. Turn the keyswitch to the ON position.
D. Monitor the diagnostic codes on the electronic service tool. Check for an active -4 diagnostic code for the suspect sensor.
E. Turn the keyswitch to