90242-MB0-000 Honda NUT, LOCK (64MM) (Honda Code 1243567).

Reference: Refer to the Disassembly and Assembly for the appropriate procedure for the removal and installation of components.
Table 2
Troubleshooting Test Steps Values Results
1. Check the Diesel Exhaust Fluid (DEF) Tank Filler Cap.
A. Clean dirt and debris from around the tank cap before removing the cap. Blockages can be caused by a build-up of dirt and debris around the cap.
Note : A blocked DEF filler cap can cause a 5392-31 or E1370 (2) code.
B. Remove and inspect the filler cap for blockages.
DEF Filler Cap
Result : A blockage was not found.
Proceed to Test Step 2.
Result : A blockage was found.
Repair : Rinse the cap gently with clean water or replace the cap. The cap contains a membrane so care must be taken not to damage the membrane. If the cap cannot be cleaned, replace the cap.
Proceed to Test Step 2.
2. Check the Diesel Exhaust Fluid (DEF) Gauge.
A. Turn the keyswitch to ON. Do not start the engine.
B. Check the current position of the DEF gauge.
C. Turn the keyswitch to OFF.
D. Clean dirt and debris from around the tank cap before removing the cap. Add or remove DEF from the DEF tank.
Note : Only use DEF that meets ISO 22241 quality standards.
E. Turn the keyswitch to ON. Do not start the engine.
F. Check for a change in the DEF gauge position.
DEF Gauge
Result : The gauge did not move by adding or removing DEF from the tank.
Proceed to Test Step 3.
Result : The gauge moved by adding or removing DEF from the tank.
Proceed to Test Step 4.
3. Check the Electrical Connection at the DEF Tank Header.
A. Turn the keyswitch to OFF.
B. Inspect the electrical connections to the DEF tank header. Refer to Troubleshooting, "Electrical Connectors - Inspect" for further information.
C. Inspect the connections for corrosion or loose wires.
Electrical Connections
Result : The electrical connections are free of corrosion and loose wires.
Repair : Replace the DEF tank header.
Proceed to Test Step 10.
Result : The electrical connections are not free of corrosion or loose wires.
Repair : Make the necessary repairs.
Proceed to Test Step 10.
4. Inspect the DEF lines for leaks.
A. Turn the keyswitch to ON. Do not start the engine.
B. Connect to the "Aftertreatment Diesel Exhaust Fluid Controller #1" using Cat ET.
C. Navigate to "Diagnostics Tests".
D. Perform the "DEF Dosing System Verification Test" to pressurize the system.
E. Inspect all DEF lines from the tank to the DEF injector. Check for pinched, damaged, disconnected, or leaking lines.
F. Turn the keyswitch to OFF.
DEF lines
Result: A leaking or disconnected line was found.
Repair : Repair or replace the failed DEF line.
Proceed to Test Step 10.
Result: A leaking or disconnected line was not found.
Proceed to Test Step 5.
5. Check the Diesel Exhaust Fluid (DEF) quality.
A. Measure the DEF quality. Refer to Testing and Adjusting, "Diesel Exhaust Fluid Quality - Test" for the correct procedure.
DEF
Result : The DEF is not contaminated.
Proceed to Test Step 6.
Result : The DEF is contaminated.
Repair : Contact the Dealer Solutions Network (DSN) for further information.
Illustration 1 g03777280
(1) DEF Suction Line Connection on the Header Unit
Table 3
Troubleshooting Test Steps Values Results
6. Check for suction line restrictions.
A. Disconnect the suction line from the DEF tank header and DEF pump.
B. Inspect the suction line for obstructions or damage. Also, check that the line is connected in the proper locations.
Note : Possible obstructions are ice, DEF deposits, or debris.
Restrictions
Result: An obstruction or damage was found.
Repair : Flush the line with water or low-pressure air or replace the suction line.
Proceed to Test Step 10.
Result: An obstruction or damage was not found.
Repair : Reinstall the suction line.
Proceed to Test Step 7.
7. Replace the DEF pump filters.
A. Clean the area around the pump filters.
B. Replace the DEF pump suction line filter fitting. Tighten the new filter fitting to a torque of 4.5 N m (40 lb in).
C. Replace the DEF pump filter. Refer to Operation and Maintenance Manual, Diesel Exhaust Fluid Filter - Replace for the correct procedure.
DEF Pump Filters
Result : The DEF pump filters were replaced.
Proceed to Test Step 8.
8. Check the DEF pump.
A. Turn the keyswitch to ON. Do not start the engine.
B. Connect to the "Aftertreatment Diesel Exhaust Fluid Controller #1" using Cat® Electronic Technician (ET).
C. Navigate to "Diagnostics Tests".
D. Perform the "DEF Dosing System Verification Test" to pressurize the system.
E. Monitor the "DEF Pressure" on the Cat ET screen during the test to see if the pressure stabilizes.
DEF Pump
Result : The DEF pump maintained at least 800 kPa (116 psi) during the test.
Proceed to Test Step 9.
Result : The DEF pump did not maintain at least 800 kPa (116 psi) during the test.
Repair : Replace the DEF pump.
Proceed to Test Step 10.
9. Replace the Filters and Flush the DEF Tank
A. Turn the keyswitch to OFF.
B. Remove DEF tank header from the DEF tank.
C. Flush the DEF tank and replace the DEF filters. Refer to Testing and Adjusting, "Diesel Exhaust Fluid Tank - Flush" for the correct procedure.
DEF Tank Filters
Result: The DEF tank was flushed and the filters were replaced.
Proceed to Test Step 10.
10. Perform an "Aftertreatment System Functional Test".
A. Start the engine.
B. Connect to the "Engine #1 Aftertreatment Controller" using Cat ET.
C. Navigate to "Diagnostics Tests".
D. Perform the "Aftertreatment System Functional Test".
"Aftertreatment System Functional Test"
Result: The test is successful.
Return the unit to service.
Result: The test is not successful.
Proceed to Test Step 11.
11. Perform the "DEF Dosing System Accuracy Test" Using Cat ET
A. Refer to Testing and Adjusting, Aftertreatment SCR System Dosing Test for the correct procedure.
"DEF Dosing System Accuracy Test"