3516E Engine for Tier 4 Final 994K Wheel Loaders Caterpillar

DEF Tank Level Is Low

Usage:

994K SMX

Use this procedure to troubleshoot a low Diesel Exhaust Fluid (DEF) tank level. Also, use this procedure if one of the following event codes is active or logged.

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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
Float

Recommended Actions

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Illustration 1	g06302029
(1) Aftertreatment #2 DEF pump #2 header (red) (2) Aftertreatment #2 DEF pump #1 header (yellow) (3) Aftertreatment #1 DEF pump #1 header (blue) (4) Aftertreatment #1 DEF pump #2 header (green)

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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).