C175 Tier 4 Final Engines for Off-Highway Trucks Caterpillar

DEF Pump - Replace

Usage:

793F D3T

Table 1 lists the diagnostic codes for the Diesel Exhaust Fluid (DEF) pump circuit.

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Table 1
J1939 Code	CDL Code	Comments
3361–8 Aftertreatment #1 DEF Dosing Unit : Abnormal Frequency, Pulse Width, or Period	3102–8 Aftertreatment #1 DEF Dosing Unit : Abnormal Frequency, Pulse Width, or Period	The Aftertreatment #1 Diesel Exhaust Fluid Control Unit (DCU) #1 detects an abnormal motor speed signal from the pump. The code is logged.
4337-8 Aftertreatment 1 Diesel Exhaust Fluid Dosing Temperature : Abnormal Frequency, Pulse Width, or Period	3096-8 Aftertreatment 1 Diesel Exhaust Fluid Dosing Temperature : Abnormal Frequency, Pulse Width, or Period	The Aftertreatment #1 DCU #1 detects an abnormal temperature signal from the pump. The code is logged.
4376-7 Aftertreatment 1 Diesel Exhaust Fluid Return Valve : Not Responding Properly	3862-7 Aftertreatment 1 Diesel Exhaust Fluid Return Valve : Not Responding Properly	The Aftertreatment #1 DCU #1 detects that the return valve is not responding properly. The code is logged.
4390–8 Aftertreatment 2 Diesel Exhaust Fluid Doser 1 Temperature : Abnormal Frequency, Pulse Width, or Period	3098–8 Aftertreatment 2 Diesel Exhaust Fluid Doser 1 Temperature : Abnormal Frequency, Pulse Width, or Period	The Aftertreatment #2 DCU #1 detects an abnormal temperature signal from the pump. The code is logged.
4442–7 Aftertreatment 2 Diesel Exhaust Fluid Dosing Unit 1 Diverter Valve : Not Responding Properly	5009–7 Aftertreatment 2 Diesel Exhaust Fluid Dosing Unit 1 Diverter Valve : Not Responding Properly	The Aftertreatment #2 DCU #1 detects that the return valve is not responding properly. The code is logged.
4451–8 Aftertreatment #2 DEF Dosing Unit : Abnormal Frequency, Pulse Width, or Period	3109–8 Aftertreatment #2 DEF Dosing Unit : Abnormal Frequency, Pulse Width, or Period	The Aftertreatment #2 DCU #1 detects an abnormal motor speed signal from the pump. The code is logged.
7457–8 Aftertreatment 1 Diesel Exhaust Fluid Dosing Unit 2 : Abnormal Frequency, Pulse Width, or Period	5032–8 Aftertreatment 1 Diesel Exhaust Fluid Dosing Unit 2 : Abnormal Frequency, Pulse Width, or Period	The Aftertreatment #1 DCU #2 detects an abnormal motor speed signal from the pump. The code is logged.
7460–8 Aftertreatment 1 Diesel Exhaust Fluid Doser 2 Temperature : Abnormal Frequency, Pulse Width, or Period	3097–8 Aftertreatment 1 Diesel Exhaust Fluid Doser 2 Temperature : Abnormal Frequency, Pulse Width, or Period	The Aftertreatment #1 DCU #2 detects an abnormal temperature signal from the pump. The code is logged.
7462–8 Aftertreatment 2 Diesel Exhaust Fluid Dosing Unit 2 : Abnormal Frequency, Pulse Width, or Period	5033–8 Aftertreatment 2 Diesel Exhaust Fluid Dosing Unit 2 : Abnormal Frequency, Pulse Width, or Period	The Aftertreatment #2 DCU #2 detects an abnormal motor speed signal from the pump. The code is logged.
7465–8 Aftertreatment 2 Diesel Exhaust Fluid Dosing 2 Temperature : Abnormal Frequency, Pulse Width, or Period	3099–8 Aftertreatment 2 Diesel Exhaust Fluid Dosing 2 Temperature : Abnormal Frequency, Pulse Width, or Period	The Aftertreatment #2 DCU #2 detects an abnormal temperature signal from the pump. The code is logged.
7536–7 Aftertreatment 1 Diesel Exhaust Fluid Dosing Unit 2 Diverter Valve : Not Responding Properly	5008–7 Aftertreatment 1 Diesel Exhaust Fluid Dosing Unit 2 Diverter Valve : Not Responding Properly	The Aftertreatment #1 DCU #2 detects that the return valve is not responding properly. The code is logged.
7537–7 Aftertreatment 2 Diesel Exhaust Fluid Dosing Unit 2 Diverter Valve : Not Responding Properly	5010–7 Aftertreatment 2 Diesel Exhaust Fluid Dosing Unit 2 Diverter Valve : Not Responding Properly	The Aftertreatment #2 DCU #2 detects that the return valve is not responding properly. The code is logged.

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Illustration 1	g06084782
(1) Aftertreatment #1 DCU #1 (2) Aftertreatment #1 DCU #2 (3) Aftertreatment #2 DCU #1 (4) Aftertreatment #2 DCU #2

Probable Causes

Codes
Connectors and wiring
Leaks

Recommended Actions

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Table 2
Troubleshooting Test Steps	Values	Results
1. Check for Codes A. Connect Cat^® Electronic Technician (ET) to the service tool connector. B. Look for active codes that are associated with the system for the event code.	Codes	Result: An associated code is active. Repair: Troubleshoot the associated code before continuing with this test. Result: A code is active or logged. Proceed to Test Step 2.
2. Inspect the Electrical Connectors and the Wiring A. Turn the keyswitch to the OFF position for 2 minutes. The keyswitch must be OFF for 2 minutes to allow the Diesel Exhaust Fluid (DEF) pump to purge, reset the code, and reset the Diesel Exhaust Fluid Controller Unit (DCU). B. Disconnect the affected DEF pump electrical connector. C. Inspect the connector terminals for DEF contamination or corrosion.	Connector and Wiring	Result: The connectors and/or wiring appear to be OK. Proceed to Test Step 3. Result: There is a problem with the connectors and/or wiring. Repair: Replace the Pump Electronic Tank Unit (PETU) connector or wiring. Ensure that all the seals are properly in place and ensure that the connectors are coupled. Proceed to Test Step 3.
3. Replace the Affected DEF Pump A. Turn the keyswitch to the OFF position for 2 minutes. The keyswitch must be OFF for 2 minutes to allow the DEF pump to purge, reset the code, and reset the DCU. B. Replace the appropriate DEF pump. Refer to the Disassembly and Assembly manual for additional information. C. Turn the keyswitch to the ON position. Do not start the engine. D. Connect Cat ET. E. Select the "Selective Catalyst Reduction System". F. Perform the following diagnostic test to pressurize the system: -"Aftertreatment Dosing System Functional Test" G. Visually inspect all DEF lines from the tank to the DEF injectors. Look for pinched, damaged, or disconnected lines. H. Turn the keyswitch to the OFF position.	Leaks	Result: The lines are not leaking and the test completed successfully. Return to service. Result: The test did not complete successfully. Repair: Perform the following procedure: 1. Repair or replace the damaged components. 2. Connect Cat ET. 3. Select the "Selective Catalyst Reduction System". 4. Perform the following diagnostic test to pressurize the system: -"Aftertreatment Dosing System Functional Test" 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).