CAP 4S6835 - Caterpillar

Table 1
Diagnostic Trouble Codes for the DEF Pump
J1939 Code CDL Code Code Description
(code descriptions may vary) Comments
4374-5 3118-5 Aftertreatment #1 Diesel Exhaust Fluid Pump Motor Speed : Current Below Normal This code indicates low current to the DEF pump motor.
The code is logged.
4374-6 3118-6 Aftertreatment #1 Diesel Exhaust Fluid Pump Motor Speed : Current Above Normal This code indicates high current to the DEF pump motor.
The code is logged.
5706-5 3607-5 Aftertreatment #1 Diesel Exhaust Fluid Pump Heater : Current Below Normal This code indicates low current to the DEF pump heater.
The code is logged.
5706-6 3607-6 Aftertreatment #1 Diesel Exhaust Fluid Pump Heater : Current Above Normal This code indicates high current to the DEF pump heater.
The code is logged.
Follow the troubleshooting procedure to identify the root cause of the problem.
Table 2
Troubleshooting Test Steps Values Results
1. Check that the Latest Available Software is Installed
A. Ensure that the latest software is installed on the engine ECM.
B. Ensure that the latest software is installed on the Dosing Control Unit (DCU)
If necessary, refer to Troubleshooting, "ECM Software - Install" for the correct procedure.
Software
Result: The latest software is not installed.
Repair: Install the latest engine ECM software and then install the latest DCU software. If necessary, refer to Troubleshooting, "ECM Software - Install" for the correct procedure.
Start the engine and wait for 2 minutes.
If the fault is cleared, return the engine to service.
If the fault is still present, proceed to Test Step 2.
Result: The latest software is installed.
Proceed to Test Step 2.
2. Determine the Diagnostic Code
A. Establish communication between the electronic service tool and the engine Electronic Control Module (ECM). Refer to Troubleshooting, "Electronic Service Tools"
B. Establish communication between the electronic service tool and the Dosing Control Unit (DCU).
C. Look for active codes.
Diagnostic Trouble Codes
Result: There is an active XXXX-5 or XXXX-6 diagnostic code.
Proceed to Test Step 3.
3. Check the Battery Voltage
A. Turn the keyswitch to the OFF position.
B. Use a suitable multimeter to measure the battery voltage.
At least 12.5 V for a 12 V system
At least 25V for a 24V system
Result: The battery voltage is lower than the expected range.
Repair: Refer to Troubleshooting, Battery Problem to investigate the cause of low battery voltage.
Result: The battery voltage is within the expected range.
Proceed to Test Step 4.
4. Inspect Electrical Connectors and Wiring
A. Thoroughly inspect the 31-pin connector for the PEU. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
B. Thoroughly inspect the connectors for the coolant diverter valve and the DEF injector. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
C. Perform a 45 N (10 lb) pull test on each of the wires in the 31-pin and solenoid connectors associated with the diagnostic code.
D. Ensure that the DCU connector is securely connected and locked in place.
E. Check the harness for corrosion, abrasion, and pinch points from the solenoids to the ECM.
Loose connection or damaged wire
Result: There is a fault in a connector or the wiring.
Repair: Repair any faulty connectors or replace the wiring harness. Ensure that all the seals are properly in place and