FUSO 4M4 – INTAKE AND EXHAUST – ON-VEHICLE INSPECTION AND ADJUSTMENT – Inspection of Diesel Particulate Filter Unit for Clogging and Cleaning of the Diesel Particulate Filter Unit

• These works should be performed at 12-month intervals as follows:

7.1 Preparation
• Place the transmission in neutral.
• Turn the steering wheel in neutral position and securely apply the parking brake.
• Turn off lamps and accessory devices not to increase the engine speed.
• Connect the Multi-Use Tester. (See Gr00.)
• Check diagnosis code of each electronic control system. If any fault exists, rectify it.
• Warm up the engine until the engine coolant has been heated to more than 70°C.
(Check by Multi-Use Tester service data “13: Water Temperature”.)

7.2 Inspection procedure
• Perform inspection following the flowchart shown below.

• Measure the pressure difference following the procedure shown below.
– Check that the exhaust gas temperature is 150°C to 300°C.
(Check by Multi-Use Tester service data “0F: Exhaust gas temperature 1”.)
– Fully press the accelerator pedal (no-load maximum speed).
– Measure the pressure difference between the exhaust gas inlet and outlet of the diesel particulate filter.
(Measure by Multi-Use Tester service data “11: Difference pressure across DPF”.)
• If the pressure difference is below 20 kPa, follow the procedure
(1) shown below. If the pressure difference is 20 kPa or more, follow the procedure (2).
(1) When pressure difference between exhaust gas inlet and outlet of diesel particulate filter is below 20 kPa
(1.1) Regeneration by Multi-Use Tester
• In this regeneration, the temperature of the ceramic filter is raised to burn the particulate matter collected in it. When burning the particulate matter, the ceramic filter may emit a burning odor, which is not abnormal.
• Idle the engine (no-load minimum speed).
• Apply the parking brake securely.
• Conduct the regeneration of the diesel particulate filter using the
Multi-Use Tester. (Perform actuator test by Multi-Use Tester “A2: DPF Regeneration”.)

• During regeneration, the engine speed increases.
(1.2) Visual check
• Disassemble the diesel particulate filter and check for the following items.
– Adhesion of a large amount of soot to the inside of the outlet body
– Damage to the rear end of the ceramic filter
• If a large amount of soot is adhered to the inside of the outlet body, check the exhaust gas because engine-related parts may be abnormal. (See later section.)

(1.3) Cleaning
• The purpose of the cleaning made after regeneration is to remove the ashes produced from the combustion of particulate matters (PM).
• Set the filter body in with the exhaust gas outlet side facing upward. (Outlet body side)
• Adjust the air tank pressure of to 0.6 MPa {6.1 kgf/cm2} and press and hold the operation switch for more than 3 seconds.
• Repeat the above operation 5 times.
• shall be operated in accordance with the operation manual.

(1.4) Pressure difference measurement
• The purpose of the differential pressure measurements taken after the cleaning is to verify that the inside of the diesel particulate filter is cleaned up sufficiently.
• Check that the exhaust gas temperature is 150°C to 300°C.
(Check by Multi-Use Tester service data “0F: Exhaust gas temperature 1”.)
• Fully press the accelerator pedal (no-load maximum speed).
• Measure the pressure difference between the exhaust gas inlet and outlet of the diesel particulate filter.
(Measure by Multi-Use Tester service data “11: Difference pres-
sure across DPF”.)

(1.5) Pressure difference measurement
• The purpose of the differential pressure measurements taken after the cleanings which are not performed at an interval of 3 years or 150,000 km running is to check if the Particulate matter (PM) deposit affects the regeneration control of the diesel particulate filter.
• Check that the exhaust gas temperature is 150°C to 300°C.
(Check by Multi-Use Tester service data “0F: Exhaust gas temperature 1”.)
• Fully press the accelerator pedal (no-load maximum speed).
• Measure the pressure difference between the exhaust gas inlet and outlet of the diesel particulate filter.
(Measure by Multi-Use Tester service data “11: Difference pressure across DPF”.)

(2) When pressure difference between exhaust gas inlet and outlet of diesel particulate filter is 20 kPa or more
(2.1) Visual check
• Disassemble the diesel particulate filter and check for the following items.
• Adhesion of a large amount of soot to the inside of the outlet body
• Damage to the rear end of the ceramic filter
• If a large amount of soot is adhered to the inside of the outlet body, check the exhaust gas because engine-related parts may be abnormal. (See later section.)

(2.2) Cleaning
• The purpose of the cleaning made before regeneration is to remove the excessive ashes beforehand because the regeneration (combustion) with a large amount of ashes accumulated on the ceramic filter can cause the filter section to break.
• Set the filter body in with the exhaust gas outlet side facing upward. (outlet body side)
• Adjust the air tank pressure of to 0.6 MPa {6.1 kgf/cm2} and press and hold the operation switch for more than 3 seconds.
• Repeat the above operation 5 times.
• shall be operated in accordance with the operation manual.

(2.3) Pressure difference measurement
• The purpose of the differential pressure measurements taken after the cleaning is to verify that the inside of the diesel particulate filter is cleaned up sufficiently.
• Check that the exhaust gas temperature is 150°C to 300°C.
(Check by Multi-Use Tester service data “0F: Exhaust gas temperature 1”.)
• Fully press the accelerator pedal (no-load maximum speed).
• Measure the pressure difference between the exhaust gas inlet and outlet of the diesel particulate filter.
(Measure by Multi-Use Tester service data “11: Difference pressure across DPF”.)

(2.4) Regeneration by Multi-Use Tester
• In this regeneration, the temperature of the ceramic filter is raised to burn the particulate matter collected in it.
When burning the particulate matter, the ceramic filter may emit a burning odor, which is not abnormal.
• Idle the engine (no-load minimum speed).
• Apply the parking brake securely.
• Conduct the regeneration of the diesel particulate filter using the Multi-Use Tester. (Perform actuator test by Multi-Use Tester “A2: DPF Regeneration”.)

• During regeneration, the engine speed increases.

(2.5) Cleaning
• The purpose of the cleaning made before regeneration is to remove the ashes produced from the combustion of particulate matters (PM).
• Set the filter body in with the exhaust gas outlet side facing upward. (outlet body side)
• Adjust the air tank pressure of to 0.6 MPa {6.1 kgf/cm2} and press and hold the operation switch for more than 3 seconds.
• Repeat the above operation 5 times.
• shall be operated in accordance with the operation manual.

(2.6) Pressure difference measurement
• The purpose of the differential pressure measurements taken after twice the cleaning is to verify that the inside of the diesel particulate filter is cleaned up sufficiently.
• Check that the exhaust gas temperature is 150°C to 300°C.
(Check by Multi-Use Tester service data “0F: Exhaust gas temperature 1”.)
• Fully press the accelerator pedal (no-load maximum speed).
• Measure the pressure difference between the exhaust gas inlet and outlet of the diesel particulate filter.
(Measure by Multi-Use Tester service data “11: Difference pressure across DPF”.)

(2.7) Initialization of the DPF-related information
• Initialize the historical records of DPF-related information using Multi-Use Tester.
(See “9. Initialization of the DPF-Related Information”.)

 

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