C7.1 Engines Caterpillar

DEF Module Does Not Respond

Usage:

C7.1 881

Download the "Warranty Report" from the engine ECM before performing any troubleshooting or clearing diagnostic trouble codes.

Use this procedure to troubleshoot the following codes:

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

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Table 1
Diagnostic Trouble Codes for DEF Module Does Not Respond
J1939 Code	CDL Code	Code Description (code descriptions may vary)	Comments
3361-7	3821-7	Aftertreatment #1 DEF Dosing Unit : Not Responding Properly	The DEF injector is not functioning properly.
3361-11	3821-11	Aftertreatment #1 DEF Dosing Unit : Other Failure Mode	There is a short circuit in the DEF injector wiring.
3361-14	3821-14	Aftertreatment #1 DEF Dosing Unit : Special Instruction	The DEF injector is not functioning properly.

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Table 2
Required Tools
Tool	Part Number	Part Description	Qty
A	398-4987	Probe - Female (Part of 372-5260 Tool Gp)	2
B	398-4985	Probe - Male (Part of 372-5260 Tool Gp)	2

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

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Table 3
Troubleshooting Test Steps	Values	Results
1. Check the Resistance of the DEF Injector A. Turn the keyswitch to the OFF position. Allow 2 minutes to elapse before proceeding. B. Disconnect the DEF injector from the applicable harness. C. Inspect the connector for damage or debris. D. Connect Tooling A to the DEF injector. The probes must be used to prevent damage to the DEF injector connector. E. Measure the resistance of the DEF injector.	10 Ohms to 20 Ohms	Result : The resistance of the DEF injector measured between 10 Ohms and 20 Ohms. Proceed to Test Step 2. Result : The resistance of the DEF injector did not measure between 10 Ohms and 20 Ohms. A failed DEF injector has been detected. Repair : Replace the failed DEF injector. Refer to the Disassembly and Assembly, "DEF Injector and Mounting - Remove and Install". Proceed to Test Step 8.
2. Check for a Short Circuit in the Wiring Harness. A. Turn the keyswitch to the OFF position. Allow 2 minutes to elapse before proceeding. B. Disconnect the injector from the applicable harness C. Connect Tooling B to the DEF injector harness connector. The probes must be used to prevent damage to the connector. D. Measure the resistance between the two probes. Note : The reading will measure the resistance in the wiring harness between the DEF injector connector and the DCU.	Ohms	Result : The resistance of the DEF injector wiring harness measured greater than 10K Ohms. Repair : Connect the injector to the applicable harness. Proceed to Test Step 3. Result : The resistance of the DEF injector wiring harness did not measure greater than 10K Ohms. Repair : There is a short circuit in the wiring harness between the DEF injector connector and the DCU. Repair or replace the wiring harness. Connect the injector to the applicable harness. Proceed to Test Step 8.
3. Check the Diesel Exhaust Fluid (DEF) Quality. A. Measure the DEF quality. Refer to Testing and Adjusting, "Diesel Exhaust fluid Quality - Test" for the correct procedure.	DEF	Result : The DEF is not contaminated and the concentration is within the acceptable range. Proceed to Test Step 4. Result : The DEF is not contaminated but the concentration is not within the acceptable range. Repair : Drain the DEF from the tank. Refill the tank with DEF that meets ISO 22241 quality standards. Proceed to Test Step 8. Result : The DEF is contaminated. Repair : Contact the Dealer Solutions Network (DSN) for further information.
4. Perform the "DEF Dosing System Accuracy Test" A. Use the electronic service tool to 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 system accuracy test	Result : The quantity collected is below specification. Proceed to Test Step 5. Result : The quantity collected is within specification. Proceed to Test Step 8. Result : The quantity collected is above specification. Repair : A failed DEF injector has been detected, replace the failed DEF injector. Refer to the Disassembly and Assembly, "DEF Injector and Mounting - Remove and Install". Proceed to Test Step 7.
5. Check the DEF Pressure Line A. Turn the keyswitch to the OFF position. Allow 2 minutes to elapse before proceeding. 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 Disassembly and Assembly, "Diesel Exhaust Fluid Lines - Remove and Install" for the correct procedure. D. Inspect the DEF pressure line for obstructions. Flush the line with water or low-pressure air, if necessary. Note : Possible obstructions are ice, DEF deposits, or debris.	Restriction, obstructions, and leaks	Result : There are restrictions or leaks in the lines. Repair : Flush or replace the line. Proceed to Test Step 7. Result : An obstruction was not found and the line was not damaged. Proceed to Test Step 6.
6. Replace the DEF Injector A. Turn the keyswitch to the OFF position. B. Remove the DEF injector. Refer to Disassembly and Assembly, "DEF Injector and Mounting - Remove and Install". C. Connect the new DEF injector to the DEF pressure line and the electrical connector. Note: Do not install the new injector until Test Step 7 has been completed.	DEF injector	Result: The DEF injector was connected to the DEF pressure line and the electrical connector. Proceed to Test Step 7.
7. Perform the DEF Dosing System Accuracy Test A. Use the electronic service tool to perform a "DEF Dosing System Accuracy Test". Refer to Testing and Adjusting, "Aftertreatment SCR System Dosing Test" for the correct procedure.	DEF dosing system accuracy test	Result: The quantity collected is within specification. Install the new DEF injector. Refer to Disassembly and Assembly, DEF Injector and Mounting Remove and Install. Proceed to Test Step 8. Result: The quantity collected is not within specification. Repair : Replace the DEF pump. Refer to the Disassembly and Assembly manual for the correct procedure. Install the new DEF injector. Refer to Disassembly and Assembly, DEF Injector and Mounting Remove and Install. Proceed to Test Step 8.
8. Perform the Aftertreatment Recovery Procedure A. Connect to the electronic service tool. B. Perform the "Aftertreatment Recovery Procedure".	Aftertreatment Recovery Procedure	Result: The Aftertreatment Recovery Procedure completed successfully. Proceed to Test Step 9. Result: The Aftertreatment Recovery Procedure was not successful. Contact the Dealer Solutions Network (DSN).
9. Perform an "Aftertreatment System Functional Test" A. Turn the keyswitch to the ON position. B. Use the electronic service tool to perform an "Aftertreatment System Functional Test". C. Download a warranty report. Refer to "Aftertreatment Abnormal Shutdown History" under the "Information" tab in the "Engine #1 Aftertreatment Controller". Note : If hot shutdowns have occurred, allow the engine to cool down before shutting the machine OFF.	Electronic service tool test	Result : The test was successful. Return the unit to service. Result : The test not was successful and additional codes were logged. Repair : Troubleshoot the additional codes, refer to theTroubleshooting manual for the correct procedure.