COVER ASSEM. 5K7914 - Caterpillar

Table 1
Diagnostic Trouble Codes for DEF Tank Temperature Is High
J1939 Code Description Notes
3031-16 Catalyst Tank Temperature : High - moderate severity (2) The temperature of the Diesel Exhaust Fluid (DEF) in the DEF tank has risen above 70° C (158° F) for at least 1 second.
The warning lamp will flash. The engine is derated.
The diagnostic code will clear when the DEF tank temperature is below 65° C (149° F) for at least 2 seconds.
Follow the troubleshooting procedure in order to identify the root cause of the problem.
Illustration 1 g03715797
View of the coolant diverter valve
(1) Coolant outlet connection
(2) Electrical connector
(3) Coolant inlet connection
Illustration 2 g03715798
View of the DEF tank and DEF tank header unit
(4) Coolant inlet connection
(5) Electrical connector
(6) Coolant outlet connection Complete the procedure in the order in which the steps are listed.
Table 2
Troubleshooting Test Steps Values Results
1. Check for Associated Codes
A. Connect to the electronic service tool.
B. Check for diagnostic codes relating to the DEF tank temperature sensor, the coolant diverter valve, or high coolant temperature.
Associated code
Result: An associated code is present.
Repair: Troubleshoot the associated code. Refer to Troubleshooting, "Diagnostic Trouble Codes" for the correct procedure.
Result: An associated code is not present.
Proceed to Test Step 2.
2. Check for Corrosion in the Connector to the Tank Header
A. Inspect electrical connector (2) for the coolant diverter valve. Inspect electrical connector (5) for the DEF tank header. Refer to Troubleshooting, "Electrical Connectors - Inspect" for further information.
Corrosion
Result: There is not corrosion in the connector to the tank header or the coolant diverter valve.
Proceed to Test Step 3.
Result: There is corrosion in the connector to the tank header or the coolant diverter valve.
Repair: Repair or replace the connector. Cycle the keyswitch.
Return the unit to service.
3. Check the Coolant Supply and Return Lines for Correct Installation
A. Inspect coolant inlet (3) and outlet (1) lines from coolant diverter valve. Make sure that the coolant is flowing in the correct direction. Refer to Illustration 1.
B. Inspect coolant inlet (4) and coolant outlet (6) . Make sure that the coolant is flowing in the correct direction. Refer to Illustration 2.
Correct installation
Result: The lines are installed correctly.
Proceed to Test Step 4.
Result: The lines are not installed correctly.
Repair: Correctly install the lines.
Proceed to Test Step 5.
4. Check the Coolant Diverter Valve Solenoid for Correct Operation
A. Turn the keyswitch to the OFF position.
B. Disconnect the wiring harness connector from coolant diverter valve (2).
C. Turn the keyswitch to the ON position.
D. Connect to the electronic service tool.
E. Start the engine. Allow the engine to warm up to operating temperature.
F. Use the electronic service tool to monitor the "DEF Tank Temperature".
G. Turn the keyswitch to the OFF position.
Temperature rise
Result: The DEF tank temperature did not increase.
Connect the coolant diverter valve to the wiring harness.
Proceed to Test Step 5.
Result: The DEF tank temperature increased.
Repair: The coolant diverter valve is not operating correctly. Replace the coolant diverter valve. Refer to Disassembly and Assembly, "Solenoid Valve (DEF Heater Coolant) - Remove and Install".
Proceed to Test Step 5.
5. Replace the DEF
A. Drain the DEF from the