ROLLER GP- 1181615 - Caterpillar

Table 1
Diagnostic Trouble Codes for DEF Pressure Is Low
J1939 Code CDL Code Code Description
(code descriptions may vary) Comments
4334-7 3090-7 Aftertreatment #1 DEF #1 Pressure (absolute) : Not Responding Properly DEF pump pressure is not stable after the initial priming sequence
OR
The DEF pump is not able to supply DEF after the line heaters have been energized and a heating cycle has been completed
4334-18 E931 (2) Aftertreatment #1 DEF #1 Pressure (absolute) : Low - moderate severity (2) Diesel Exhaust Fluid (DEF) system pressure dropped below the acceptable threshold during dosing
5392-31 E1370 (2) Aftertreatment #1 DEF Dosing Unit #1 Loss of Prime Diesel Exhaust Fluid (DEF) system pressure was not achieved during priming
Table 2
Troubleshooting Test Steps Values Results
1. Check the Diesel Exhaust Fluid (DEF) tank filler cap
A. Clean dirt and debris from around the tank cap before removing the cap. Blockages can be caused by a build-up of dirt and debris around the cap.
Note : A blocked DEF filler cap can cause a 5392-31 or E1370 (2) code.
B. Remove and inspect the filler cap for blockages.
DEF filler cap
Result : A blockage was not found.
Proceed to Test Step 2.
Result : A blockage was found.
Repair : Rinse the cap gently with clean water or replace the cap.
Note: The cap contains a membrane so care must be taken not to damage the membrane. If the cap cannot be cleaned, the cap must be replaced.
Proceed to Test Step 2.
2. Check the Diesel Exhaust Fluid (DEF) Gauge
A. Turn the keyswitch to the ON position. Do not start the engine.
B. Check the current position of the DEF gauge.
C. Turn the keyswitch to the OFF position.
D. Clean dirt and debris from around the tank cap before removing the cap. Add or remove DEF from the DEF tank.
Note : Only use DEF that meets ISO 22241 quality standards.
E. Turn the keyswitch to the ON position. Do not start the engine.
F. Check for a change in the DEF gauge position.
DEF gauge
Result : The gauge did not move by adding or removing DEF from the tank.
Proceed to Test Step 3.
Result : The gauge moved by adding or removing DEF from the tank.
Proceed to Test Step 4.
3. Check the Electrical Connection at the DEF Tank Header
A. Turn the keyswitch to the OFF position.
B. Inspect the electrical connections to the DEF tank header. Refer to Troubleshooting, "Electrical Connectors - Inspect" for further information.
C. Inspect the connections for corrosion or loose wires.
Electrical connections
Result : The electrical connections are free of corrosion and loose wires.
Repair : Replace the DEF tank header. Refer to the Disassembly and Assembly manual for the correct procedure.
Proceed to Test Step 10.
Result : The electrical connections are not free of corrosion or loose wires.
Repair : Make the necessary repairs.
Proceed to Test Step 10.
4. Inspect the DEF Lines for Leaks
A. Turn the keyswitch to the ON position. Do not start the engine.
B. Connect the electronic service tool.
C. Navigate to "Diagnostics Tests".
D. Perform the "DEF Dosing System Verification Test" to pressurize the system.
E. Inspect all DEF lines from the tank to the