SEAL-O-RING 8M4447 - Caterpillar

Use this procedure to troubleshoot a low Diesel Exhaust Fluid (DEF) tank temperature. Also, use this procedure if one of the following event codes is active or logged.
Table 1
J1939 Code and Description CDL Code and Description Comments
4368-1
Aftertreatment #1 DEF Tank #2 Temperature : Low - most severe (3) E1399 (3)
Low Aftertreatment #1 DEF Tank #2 Temperature The Diesel Exhaust Fluid (DEF) tank temperature is low.
4368-17
Aftertreatment #1 DEF Tank #2 Temperature : Low - least severe (1) E1399 (1)
Low Aftertreatment #1 DEF Tank #2 Temperature The DEF tank temperature is low.
4368-18
Aftertreatment #1 DEF Tank #2 Temperature : Low - moderate severity (2) E1399 (2)
Low Aftertreatment #1 DEF Tank #2 Temperature The DEF tank temperature is low.
Table 2
Associated Codes
J1939 Code CDL Code Troubleshooting Procedure
4368-3 3135-3 Troubleshooting, "DEF Tank Sensor - Test"
4368-4 3135-4 Troubleshooting, "DEF Tank Sensor - Test" Probable Causes
Codes
SensorRecommended Actions
Table 3
Troubleshooting Test Steps Values Results
1. Check for Codes
A. Turn the DC breaker, located in the power distribution box, to the ON position.
B. Connect Cat® Electronic Technician (ET) to the service tool connector.
C. 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 DEF Tank #2 Temperature Sensor
A. Turn the DC breaker, located in the power distribution box, to the ON position.
B. Connect Cat ET.
C. Use Cat ET to monitor the following temperature:
- "Cabinet Temperature"
- "DEF Tank #2 Temperature"
Sensor
Result: The "DEF Tank #2 Temperature" is within 5° C (9° F) of the "Cabinet Temperature".
Repair:The DEF Tank temperature is too low. Contact your TC for assistance.
Result: The "DEF Tank #2 Temperature" is not within 5° C (9° F) of the "Cabinet Temperature".
Repair: A failed DEF tank temperature sensor has been detected. Replace the DEF header assembly.
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).