91306-ZY3-003 Honda O-RING (23.5X2) (Honda Code 6994545).

Table 2
Required Service Tools
Part Number Description
441-0451 Kit - Test
Table 3
Troubleshooting Test Steps Values Results
1. 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 and the concentration is not within the acceptable range.
Repair : Drain the DEF from the tank. Refill the tank with DEF that meets ISO 22241 quality standards.
Proceed to Test Step 2.
Result : The DEF is not contaminated and the concentration is within the acceptable range.
Proceed to Test Step 2.
Result : The DEF is contaminated.
Repair : Contact the Dealer Solutions Network (DSN) for further information.
2. Perform a "DEF Dosing System Accuracy Test"
A. Perform a "DEF Dosing System Accuracy Test" using Cat® Electronic Technician (ET). Refer to Testing and Adjusting, Aftertreatment SCR System Dosing Test for the correct procedure.
DEF Dosing System Accuracy Test
Result : The quantity collected is within specifications
Repair : Install the DEF injector.
Proceed to Test Step 4.
Result : The quantity collected is below specification.
Proceed to Test Step 3.
Result : The quantity collected is above specification. A failed DEF injector has been detected.
Repair : Replace the DEF injector.
Proceed to Test Step 6.
3. Check the DEF Pressure Line
A. Turn the keyswitch to OFF for 2 minutes. The keyswitch must be OFF for 2 minutes to allow the DEF pump to purge, reset the code, and reset the Electronic Control Module (ECM).
B. Visually inspect the lines for leaks or damage.
C. Remove the DEF pressure line between the DEF pump and the DEF injector.
D. Check for ice, urea deposits, or debris in the DEF pressure line.
DEF Pressure Line
Result : There are restrictions or leaks in the lines.
Repair : Remove the restrictions or replace the pressure line.
Proceed to Test Step 6.
Result : There are no restrictions or leaks in the lines.
Proceed to Troubleshooting, "DEF Pressure is Low".
4. Inspect the Exhaust Mixer for DEF Deposits
A. Turn the keyswitch to OFF.
B. Remove the DPF outlet.
C. Inspect the exhaust mixer for DEF deposits.
Exhaust Mixer
Result : There were no DEF deposits on the exhaust mixer.
Proceed to Test Step 5.
Result : There were DEF deposits on the exhaust mixer. The exhaust mixer is damaged.
Repair : Replace the exhaust mixer.
Proceed to Test Step 6.
5. Determine the Fuel Quality
A. Take a fuel sample from the fuel tank.
Refer to Testing and Adjusting, "Fuel Quality - Test"
Fuel Quality
Result : The fuel being used does not meet the specifications for the engine.
Repair : Contact the owner of the equipment. Inform the owner that Ultra Low Sulfur Diesel must be used in order for the engine to operate properly.
Drain the fuel tank and replace the fuel with fuel that meets the specifications for the engine.
Perform a Manual DPF Regeneration using Cat ET.
Return the unit to service after the regeneration has completed.
6. Perform an "Aftertreatment System Functional Test".
A. Start the engine.
B. Connect to the ECM using Cat ET.
C. Perform an "Aftertreatment System Functional Test."
Aftertreatment System Functional Test
Result: The test completed successfully.
Return the unit to service.
If this procedure did not correct the issue, contact your Cat dealer Technical Communicator (TC). For further assistance, your TC can confer with the Dealer Solution Network (DSN).