KNOB 1221671 - Caterpillar

Table 1
Diagnostic Trouble Codes
J1939 Code and Description CDL Code and Description Comments
1761-1
Aftertreatment #1 Diesel Exhaust Fluid Tank Level : Low - most severe (3) E954 (3)
Aftertreatment #1 Diesel Exhaust Fluid Tank Level : Low - most severe (3) This code is a Level 3 inducement that becomes active when the DEF tank is empty. The engine is derated 100%, limited to low idle or 1000 RPM, and may experience 5 minute rolling shutdowns.
1761-17
Aftertreatment #1 Diesel Exhaust Fluid Tank Level : Low - least severe (1) E954 (1)
Aftertreatment #1 Diesel Exhaust Fluid Tank Level : Low - least severe (1) This code is a Level 1 inducement that becomes active when the DEF level is critically low.
1761-18
Aftertreatment #1 Diesel Exhaust Fluid Tank Level : Low - moderate severity (2) E954 (2)
Aftertreatment #1 Diesel Exhaust Fluid Tank Level : Low - moderate severity (2) This code is a Level 2 inducement that becomes active when the DEF level is critically low. Power loss may occur.
Table 2
Associated Diagnostic Codes
1235–9
5856–9
1235–14
5856–14
3516–12
3100–12 Reference: Refer to the Disassembly and Assembly for the appropriate procedure for removal and installation of components.
Table 3
Troubleshooting Test Steps Values Results
1. Check for Associated Codes
A. Connect to Cat® Electronic Technician (ET).
B. Determine if there are associated codes present.
Codes
Result: An associated code is not present.
Proceed to Test Step 2.
Result: An associated code is present.
Repair: Troubleshoot the code.
If the problem is not resolved, proceed to Test Step 2.
2. Check the DEF Fluid Level
A. Turn the keyswitch to ON. Do not start the engine.
B. Check the current position of the DEF gauge.
C. Turn the keyswitch to OFF.
D. Clean dirt and debris from around the cap before removing the cap.
E. Add DEF to the DEF tank.
Only use DEF that meets ISO 22241 quality standards.
F. Turn the keyswitch to ON.
G. Check for a change in the gauge position.
Gauge Position
Result: The gauge did not move by adding DEF to the tank.
Proceed to Test Step 3.
Result: The gauge moved by adding DEF to the tank. Turn the keyswitch to OFF for 2 minutes to allow the DEF pump to purge, reset the code, and reset the Diesel Exhaust Fluid Controller (DCU).
Return the unit to service.
3. Check the Electrical Connection at the DEF Tank Header
A. Inspect the electrical connections to the DEF tank header. Refer to Troubleshooting, Electrical Connectors - Inspect for more information.
Electrical Connections
Result: The electrical connectors are free of corrosion and are not loose.
Proceed to Test Step 4.
Result: The electrical connections are not free of corrosion and/or are loose.
Repair: Make the necessary repairs to the connectors. Turn the keyswitch to OFF for 2 minutes to allow the DEF pump to purge, reset the code, and reset the Diesel Exhaust Fluid Controller (DCU).
Return the unit to service.
4. Inspect the DEF Tank Header
A. Turn the keyswitch to OFF.
B. Remove the tank header from the tank.
C. Inspect the DEF tank header for a stuck float.
Proper Operation of the Float
Result: The float was not operating properly.
Repair: Repair the float, if possible. If the float cannot be repaired, replace the DEF tank