0283681 JOHNSON ENGINE COVER ASSY., 175

Table 1
J1939 Code and Description CDL Code and Description Comments
1761-1
Aftertreatment #1 DEF Tank Volume : Low - most severe (3) E954 (3)
Low Aftertreatment DEF Tank Level The Diesel Exhaust Fluid (DEF) tank level has fallen below a threshold.
The code is logged.
1761-17
Aftertreatment #1 DEF Tank Volume : Low - least severe (1) E954 (1)
Low Aftertreatment DEF Tank Level The DEF tank level has fallen below a threshold.
The code is logged.
1761-18
Aftertreatment #1 DEF Tank Volume : Low - moderate severity (2) E954 (2)
Low Aftertreatment DEF Tank Level The DEF tank level has fallen below a threshold.
The code is logged. Note: The Diesel Exhaust Fluid (DEF) tank level that is displayed on the gauge in the cab is an average of the volume of DEF measured by each DEF tank header in the DEF tank. Each DEF tank header displays the current volume being measured in the aftertreatment status screens in Cat® Electronic Technician (ET).Probable Causes
Codes
DEF level
Connectors and Wiring
FloatRecommended Actions
Illustration 1 g06428133
The DEF pumps are on the front side of the Pump Electronic Tank Unit (PETU).
(1) Aftertreatment #1 DEF Pump #1 header
(2) Aftertreatment #1 DEF Pump #2 header
(3) Aftertreatment #2 DEF Pump #1 header
(4) Aftertreatment #2 DEF Pump #2 header
Table 2
Troubleshooting Test Steps Values Results
1. Check for Codes
A. Connect Cat® Electronic Technician (ET) to the service tool connector.
B. Look for active codes that are associated with the system for the event code.
Codes
Result: An associated code is active.
Repair: Troubleshoot any associated codes before continuing with this test.
Result: A code is active or logged.
Proceed to Test Step 2.
2. Check the Diesel Exhaust Fluid (DEF) Tank Level
A. Add DEF to the DEF tank.
B. Check for a change in the gauge position.
DEF Level
Result: The gauge did not move by adding fluid to the tank.
Proceed to Test Step 3.
Result: The gauge moved by adding fluid to the tank. Cycle the keyswitch.
Return to service.
3. Inspect the Electrical Connectors and the Wiring
A. Inspect the electrical connections to each DEF tank header. Refer to Troubleshooting, "Electrical Connectors - Inspect" for additional information.
B. Inspect for corrosion or loose wires.
Connectors and Wiring
Result: The connectors and wiring appear to be OK.
Proceed to Test Step 4.
Result: There is a problem with the connectors and/or wiring.
Repair: Repair or replace the connectors or wiring. Ensure that all the seals are properly in place and ensure that the connectors are coupled. Cycle the keyswitch.
If the problem is not resolved, proceed to Test Step 4.
4. Inspect each DEF Tank Headers
A. Remove each of the tank headers that are connected electrically from the tank.
B. Check each tank header for proper operation.
C. Connect Cat ET.
D. Use Cat ET to monitor the DEF tank level in the status screen for the DEF tank header that is being tested to make sure that the value is changing while the float is being moved.
Float
Result: The float was not operating properly.
Repair: Repair the float. If the float cannot be repaired, replace the failed DEF tank header. Cycle the keyswitch.
Verify that the repair eliminated the problem.
If the procedure did not correct the issue, contact your Cat dealer Technical Communicator (TC). For further assistance, your TC can confer with the Dealer Solutions Network (DSN).