3512E Tier 4 Final Engines for 785G Off-Highway Trucks Caterpillar

DEF Tank Temperature Is High

Usage:

785G RTL

Use this procedure to troubleshoot a high Diesel Exhaust Fluid (DEF) tank temperature. 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
3031-16 Aftertreatment #1 DEF Tank Temperature : High - moderate severity (2)	E960 (1) High Aftertreatment #1 DEF Tank Temperature #1	The Diesel Exhaust Fluid (DEF) tank temperature exceeds 80° C (176° F) on the DEF tank header 1. The code is logged on the #1 DEF tank header.
7572-16 Aftertreatment #1 DEF Tank Temperature #2 : High - moderate severity (2)	E1696 (1) High Aftertreatment #1 DEF Tank Temperature #2	The DEF tank temperature exceeds 80° C (176° F) on the DEF tank header 2. The code is logged on the #2 DEF tank header.

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Table 2
Associated Codes
J1939 Code	CDL Code	Troubleshooting Procedure
110-0	E361 (3)	Troubleshooting, "Coolant Temperature Is High"
110-15	E361 (1)	Troubleshooting, "Coolant Temperature Is High"
110-16	E361 (2)	Troubleshooting, "Coolant Temperature Is High"

Probable Causes

Codes
Connectors and Wiring
Lines
Temperature
DEF

Recommended Actions

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Illustration 1	g06028552
Pump Electronic Tank Unit (PETU) (1) DEF pump 1 (2) Coolant diverter valve for pump 2 system (3) DEF header for pump 1 system (4) DEF pump 2 (5) Coolant diverter valve for pump 1 system (6) DEF header for pump 2 system

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Table 3
Troubleshooting Test Steps	Values	Results
1. Check for Codes A. Connect to 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. Troubleshoot any associated codes before continuing with this test. Result: A code is active or logged. Proceed to Test Step 2.
2. Inspect the Electrical Connectors and the Wiring A. Inspect the electrical connections to each of the Coolant Diverter Valves and to each of the Diesel Exhaust Fluid (DEF) tank headers. 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 3. 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. Proceed to Test Step 5.
3. Check the Coolant Supply and Return Lines for Proper Installation A. Inspect the coolant supply and return lines from the engine to the Pump Electronic Tank Unit (PETU). Make sure that the coolant is flowing in the correct direction.	Lines	Result: The supply and return lines are installed correctly. Proceed to Test Step 4. Result: The supply and return lines are not installed correctly. Repair: Correctly install the supply and return lines. Refer to the Disassembly and Assembly manual for additional information. Proceed to Test Step 5.
4. Check Coolant Diverter Valve Solenoids for Proper Operation A. Turn the keyswitch to the OFF position. B. Disconnect the coolant diverter valve wiring harness connector from both coolant diverter valves. C. Start the engine. D. Run the engine until normal operating temperature is reached. E. Connect Cat ET. F. Use Cat ET to monitor the following parameters: - "Aftertreatment DEF Tank Temperature" - "Aftertreatment DEF Tank Temperature #2" G. Turn the keyswitch to the OFF position.	Tank Temperature	Result: The tank temperature did not increase. Reconnect the coolant diverter valves to the wiring harness. Proceed to Test Step 5. Result: The tank temperature did increase. Repair: A failed coolant diverter valve have been detected. Replace the coolant diverter valve that is supplying the DEF header that had the temperature increase. Refer to the Disassembly and Assembly manual for the additional information. Proceed to Test Step 5.
5. Replace the DEF A. Drain the DEF from the tank. B. Replace with DEF that meets ISO 22241 standards.	DEF	Result: The DEF was replaced. Return to service.

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).