GEAR 2P4440 - Caterpillar

Table 1
Diagnostic Trouble Codes for the DEF Pump
J1939 Code CDL Code Code Description
(code descriptions may vary) Comments
4337-8 3096-8 Aftertreatment #1 SCR Dosing Reagent 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 DEF Return Valve : Not Responding Properly The DCU detects that the return valve is not responding properly.
The code is logged.
5798-2 3096-2 Aftertreatment #1 DEF Dosing Unit Heater Temperature : Erratic, Intermittent, or Incorrect The DCU detects that the DEF pump temperature is implausible when compared to the ambient air temperature.
Follow the troubleshooting procedure in order to identify the root cause of the problem. During the following procedure, refer to the electrical schematic for the application.Complete the procedure in the order in which the steps are listed.
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.
Repair: 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 Disassembly and Assembly, "Diesel Exhaust Fluid Pump - Remove and Install" for the correct procedure.
C. Establish communication between the electronic service tool and the DCU.
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.
Repair: 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 the electronic service tool and the engine ECM.
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.
If the fault is still present, contact the Dealer Solutions Network (DSN).