GASKET KIT 5R1427 - Caterpillar

Use this procedure to troubleshoot a problem with low Diesel Exhaust Fluid (DEF) pressure. Also, use this procedure if the following event code is active or logged.
Table 1
J1939 Code and Description CDL Code and Description Comments
6875-18
Aftertreatment #1 DEF Dosing Pressure : Low - least severe (1) E931 (1)
Low Aftertreatment #1 DEF Pressure The Diesel Exhaust Fluid (DEF) pressure is below the threshold for proper system operation.
DEF dosing is disabled.
Table 2
Associated Codes
J1939 Code CDL Code Troubleshooting Procedure
4335-15 E1969 (1) Troubleshooting, "Air Assist Pressure Is High"
4335-17 E964 (1) Troubleshooting, "Air Assist Pressure Is Low"
4335-18 E964 (2) Troubleshooting, "Air Assist Pressure Is Low"
4335-3 3092-3 Troubleshooting, "Sensor Signal (Analog, Active) - Test"
4335-4 3094-4 Troubleshooting, "Sensor Signal (Analog, Active) - Test"
4376-5 3862-5 Troubleshooting, "Solenoid Valve - Test"
4376-6 3862-6 Troubleshooting, "Solenoid Valve - Test"
6875-3 3090-3 Troubleshooting, "Sensor Signal (Analog, Active) - Test"
6875-4 3090-4 Troubleshooting, "Sensor Signal (Analog, Active) - Test"
7107-5 N/A Troubleshooting, "DEF Pump Motor - Test"
7107-6 N/A Troubleshooting, "DEF Pump Motor - Test"
7107-11 N/A Troubleshooting, "DEF Pump Motor - Test"
7416-5 N/A Troubleshooting, "Solenoid Valve - Test - Aftertreatment"
7416-6 N/A Troubleshooting, "Solenoid Valve - Test - Aftertreatment"
7417-2 N/A Troubleshooting, "DEF Pump Power Supply - Test"
7417-5 N/A Troubleshooting, "Circuit Breaker - Test"
7417-6 N/A Troubleshooting, "Circuit Breaker - Test"
Illustration 1 g03747254
Enhanced Troubleshooting Information (ETI) code
Illustration 2 g06305577
DEF Component Locations
(1) DEF Injector Nozzle
(2) DEF Inlet Line Connection
(3) DEF Pump
(4) DEF Pressure SensorProbable Causes
Codes
Gas temperature
Sensor
Leaks
DEF line
Voltage
LED light
DEF pump
DebrisRecommended Actions
Table 3
Troubleshooting Test Steps Values Results
1. Check for Codes
A. Turn the DC breaker to the ON position.
B. Connect Cat® Electronic Technician (ET) to the service tool connector.
C. Look for active codes that are associated with the system for the event code.
Codes
Result: An associated code is active.
Repair: Troubleshoot any associated codes before continuing with this test.
Result: A code is active or logged.
Record the Enhanced Troubleshooting Information (ETI) code with the event. Refer to Illustration 1 for the ETI code location.
Proceed to Test Step 2.
2. Monitor the Catalyst Intake Gas Temperature
A. Turn the DC breaker to the ON position.
B. Connect Cat ET.
C. Use Cat ET to monitor the following temperature:
- "Aftertreatment #1 SCR Catalyst Intake Gas Temperature"
Temperature
Result: The "Aftertreatment #1 SCR Catalyst Intake Gas Temperature" is less than 180° C (356° F)
Proceed to Test Step 3.
Result: The "Aftertreatment #1 SCR Catalyst Intake Gas Temperature" is 180° C (356° F) or higher.
Repair: Use Cat ET to perform the following override:
- Set the "Aftertreatment #1 SCR Dosing Air Assist Valve Command Override" to the OFF position.
Proceed to Test Step 3.
3. Check the Diesel Exhaust Fluid (DEF) Pressure Sensor
A. Turn the DC breaker to the ON position.
B. Connect Cat ET.
C. Use Cat ET to monitor the following pressure:
- "Aftertreatment #1 DEF Dosing Pressure"
Sensor
Result: The DEF pressure sensor reads 0 20 kPa (0 3 psi).
Proceed to Test Step 4.
Result: The DEF pressure sensor does not read 0 20 kPa (0 3 psi).
Repair: Replace the DEF pressure sensor.
Proceed to Test Step 13.
4. Inspect for DEF and Air Leaks
A. Turn the DC breaker to the OFF position.
B. Inspect the DEF lines between the remote DEF supply