0398338 JOHNSON FUEL PUMP ASSEMBLY

Table 1
J1939 Code and Description Comments
1761-3
Aftertreatment #1 DEF Tank Volume : Voltage Above Normal The ECM detects signal voltage that is not in the acceptable range.
The code is logged.
1761-4
Aftertreatment #1 DEF Tank Volume : Voltage Below Normal The ECM detects signal voltage that is not in the acceptable range.
The code is logged.
3031-3
Aftertreatment #1 DEF Tank Temperature : Voltage Above Normal The ECM detects signal voltage that is not in the acceptable range.
The code is logged.
3031-4
Aftertreatment #1 DEF 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: If both 1761-3 (3130-3) and 3031-3 (3134-3) codes are active at the same time, confirm that the "Aftertreatment #1 DEF Quality Sensor Installation Status" configuration parameter is programmed properly.The "Aftertreatment #1 DEF Quality Sensor Installation Status" parameter must be programmed to "Installed", if equipped with a DEF header having a 4-pin connector with an internal DEF quality sensor.Diagnostics on Cat® Electronic Technician (ET)
Illustration 1 g03359107
Not all connectors are shown, refer to the appropriate schematic
The tank header unit houses the DEF tank temperature and the DEF tank level sensors. The sensors are not serviceable individually.
Table 2
Troubleshooting Test Steps Values Results
1. Check for Diagnostic Codes
A. Establish communication between Caterpillar Electronic Technician (ET) and the Diesel Exhaust Fluid Controller (DCU) . Refer to Troubleshooting, "Electronic Service Tools", if necessary.
B. Turn the keyswitch to the ON position.
C. Look 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.
C. Turn the keyswitch to the ON position.
D. Monitor the diagnostic codes on Cat ET. Check for an active -4 diagnostic code for the suspect sensor.
E. Turn the keyswitch to the OFF position.
Short created
Result: A -4 diagnostic code became active after creating the short at the sensor connector.
The wiring is OK. Replace the DEF tank header assembly. Refer to the Disassembly and Assembly manual.
Verify that the problem is resolved by cycling the keyswitch to the OFF position for 2 minutes. Turn to the keyswitch to the ON position and check for active codes.
Result: A -4 diagnostic code does not become active for the tank header unit.
Repair or replace the wiring harness.
Verify that the problem is resolved by cycling the keyswitch to the OFF position for 2 minutes. Turn to the keyswitch to the ON position and check for active codes.
3. Create an Open at the Suspect Sensor Connector
A. Disconnect the connector of the tank header unit.
B. Turn the keyswitch to the ON position.
C. Monitor the diagnostic codes on Cat ET. Check for an active -3 diagnostic code for the suspect sensor.
D. Turn the keyswitch to the OFF position.
Create an Open
Result: A -3 diagnostic code became active after disconnecting the sensor.
The wiring is OK. Replace the DEF tank header assembly. Refer to the Disassembly and Assembly manual.
Verify that the problem is resolved by cycling the keyswitch to the OFF position for 2 minutes. Turn to the keyswitch to the ON position and check for active codes.
Result: A -3 diagnostic code does not became active after disconnecting the sensor.
Repair or replace the wiring harness.
Verify that the problem is resolved by cycling the keyswitch to the OFF position for 2 minutes. Turn to the keyswitch to the ON position and check for active codes.
Complete the procedure in the order in which the steps are listed.