VEE BELT 4M5429 - Caterpillar

Table 1 lists the diagnostic codes for the Diesel Exhaust Fluid (DEF) pump circuit.
Table 1
Diagnostic Trouble Codes    
J1939 Code    CDL Code    Code Description    Comments    
4337-8     3096-8     Aftertreatment 1 Diesel Exhaust Fluid Dosing Temperature : Abnormal Frequency, Pulse Width, or Period     The Diesel Exhaust Fluid Controller (DCU) detects an abnormal temperature signal from the pump.
The code is logged.    
4374-8     3118-8     Aftertreatment #1 Diesel Exhaust Fluid Pump Motor Speed : Abnormal Frequency, Pulse Width, or Period     The DCU detects an abnormal motor speed signal from the pump.
The code is logged.    
4376-7     3862-7     Aftertreatment 1 Diesel Exhaust Fluid Return Valve : Not Responding Properly     The DCU detects that the return valve is not responding properly.
The code is logged.    
Follow the troubleshooting procedure in order to identify the root cause of the problem.    
Table 2
Troubleshooting Test Steps    Values    Results    
1. Inspect the Harness Connector at the 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. Disconnect the DEF pump electrical connector.
C. Inspect the connector terminals for DEF contamination or corrosion.
   
DEF pump connector    
Result: The DEF pump connector was free of DEF contamination or corrosion.
Proceed to Test Step 2.
Result: The DEF pump connector was not free of DEF contamination or corrosion.
Replace the PETU wiring harness. Proceed to Test Step 2.
   
2. Replace the 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 DEF pump. Refer to the Disassembly and Assembly manual for the correct procedure.
C. Establish communication between Caterpillar Electronic Technician (ET) and the Diesel Exhaust Fluid Controller #1 ECM.
D. Perform the "DEF Dosing System Verification Test" in order to pressurize and prime the system.
E. Visually inspect all DEF lines from the tank to the DEF injector for leakage.
   
Leakage    
Result: The lines are not leaking.
Proceed to Test Step 3.
Result: The lines are leaking.
Make the necessary repairs and repeat the "DEF Dosing System Verification Test".
Proceed to Test Step 3.
   
3. Perform an "Aftertreatment System Functional Test"
A. Turn the keyswitch to the ON position.
B. Establish communication between Caterpillar Electronic Technician (ET) and the "Engine #1 Aftertreatment Controller".
C. Perform an "Aftertreatment System Functional Test".
   
Aftertreatment System Functional Test    
Result: The "Aftertreatment System Functional Test" was successful and the code cleared.
Return the unit to service.
Result: The "Aftertreatment System Functional Test" was not successful and additional codes were logged.
Troubleshoot the additional codes, Refer to Troubleshooting for the correct procedure.
   Complete the procedure in the order in which the steps are listed.