C3.4B Engines DEF Module Does Not Respond Caterpillar

DEF Module Does Not Respond

C3.4B Engines [UENR4499]

C3.4B Engines DEF Concentration Is Incorrect

C3.4B Engines DEF Pressure Is High

AIR INLET AND EXHAUST SYSTEM

AFTERTREATMENT GP

C3.4B Engines DEF Concentration Is Incorrect

C3.4B Engines DEF Module Does Not Respond

C3.4B Engines DEF Pressure Is High

C3.4B Engines DEF Does Not Purge

C3.4B Engines DEF Pressure Does Not Respond

C3.4B Engines DEF Pressure Is Low

C3.4B Engines DEF Tank Level Is Low

Use this procedure to troubleshoot the following codes:

Note: Refer to Troubleshooting, "Service Tool Features" for more information about service features.

Show/hide table

Table 1
Diagnostic Trouble Codes for DEF Module Does Not Respond
J1939 Code	Description	Notes
5394-7	Aftertreatment Diesel Exhaust Fluid Dosing Valve : Not Responding Properly	The Electronic Control Module (ECM) detects that the DEF injector does not open when requested. The battery voltage is at least 10 V. There are no other active diagnostic codes for the DEF injector. The warning lamp will flash. The engine will be derated.
Follow the troubleshooting procedure in order to identify the root cause of the problem.

Note: The procedures have been listed in order of probability. Complete the procedure in the order in which the steps are listed.

Show/hide table

Table 2
Troubleshooting Test Steps	Values	Results
1. Check for Active Diagnostic Codes A. Connect the electronic service tool to the diagnostic connector. B. Turn the keyswitch to the ON position. C. Use the electronic service tool to check for active diagnostic codes.	Diagnostic codes	Result: There are other active diagnostic codes relating to the DEF injector or the DEF quality. Repair: Troubleshoot the other diagnostic codes before returning to this procedure. Refer to Troubleshooting, "Diagnostic Trouble Codes". Result: There are no other active diagnostic codes relating to the DEF injector or the DEF quality. A 5394-7 diagnostic code is active. Proceed to Test Step 2.
2. Perform the "DEF Dosing System Accuracy Test" Note: The DEF Dosing System Accuracy Test must be performed twice. The first attempt is to dissolve DEF deposits that may have formed around the injector tip. The second attempt is the test for amount dosed. A. Perform the "DEF Dosing System Accuracy Test". Refer to Systems Operation, Testing and Adjusting, "Aftertreatment SCR System Dosing Test" for the correct procedure.	DEF dosing	Result: The quantity of DEF collected on the second test is not within the acceptable range. Proceed to Test Step 3. Result: The quantity collected is within the desired range. Proceed to Test Step 4.
3. Check the DEF Pressure Line A. Turn the keyswitch to the OFF position for 2 minutes. B. Visually inspect the lines for leaks or damage. C. Remove the DEF pressure line between the DEF pump and the DEF injector. Refer to the Disassembly and Assembly, "Diesel Exhaust Fluid Lines - Remove and Install". D. Check for ice, urea deposits, or debris in the DEF pressure line.	Pressure line	Result: There is ice in the pressure line. Repair: Check the operation of the line heaters. Refer to Troubleshooting, "DEF Line Heater - Test". Result: There are restrictions or leaks in the lines. Repair: Remove the restrictions or replace the pressure line. Result: There are no restrictions in the lines. Repair: Replace the DEF injector. Refer to Disassembly and Assembly, "DEF Injector and Mounting - Remove and Install".
4. Check that the Fault has Cleared A. Reconnect the DEF lines. Reinstall the DEF injector. B. Connect to the electronic service tool. C. Operate the engine at a high speed and load point until the SCR inlet temperature is greater than 200° C (392° F) and the DEF system starts dosing operation. D. Use the electronic service tool to check for active diagnostic codes.	Diagnostic codes	Result: The diagnostic code remains active during dosing operation. Contact the Dealer Solutions Network (DSN). Result: The diagnostic code is no longer active and now logged. Clear all logged diagnostic codes and return the engine to service.