Dpd System Regeneration Long Time - Isuzu N 2008 Series Workshop Manual

DPD System Regeneration Long Time

Checks
Definition:
The regeneration time longer than an expected time. Or, it takes longer than before.
Preliminary Checks
Sensor Checks
Fuel System Checks
Cooling System Checks
• Inspect the fuel quality.
• Inspect the Scan Tool Data List in this section.
• Inspect the Service Bulletin.
• Is the engine warm up control misunderstood as the DPD regeneration?
Inspect the driving habits/ conditions of the owner for the following conditions:
In regeneration;
• Has the manual regeneration started from cold engine?
• Is the idling time too long?
• Is the driving at slow vehicle speed too often?
• Is the PTO operating too often and/ or for a long time?
• Is the engine runtime short?
• Is the vehicle runtime short?
• Is the accelerator pedal ON and OFF too often?
• Is the ambient temperature excessively high?
Inspect the engine control sensors relating to the DPD system control for the following
conditions. Refer to Scan Tool Data List in this section.
• Misrouted or disconnected exhaust differential pressure hoses or pipes.
Notice: There is installation directionality in the exhaust differential pressure hoses.
Refer to Exhaust System in Section 1G Engine Exhaust.
• Plugged, crushed or kinked exhaust differential pressure hoses or pipes.
• Dislocated or inclined exhaust differential pressure sensor. Refer to Exhaust System
in Section 1G Engine Exhaust.
• Physical damage of the exhaust differential pressure sensor.
• Any contamination or objects that block the exhaust differential pressure sensor
port.
• Observe the Exhausts Differential Pressure parameter for a skewed or slow exhaust
differential pressure sensor.
• Skewed or slow exhaust temperature sensors. Use the Temperature vs. Resistance
table to test the exhaust temperature sensor at various temperature levels to
evaluate the possibility or a skewed sensor.
Inspect the fuel system problem. Refer to Fuel System Check chart and appropriate
procedure in Section 1D Engine Fuel.
Inspect the cooling system for an overheating conditions. Refer to Cooling System in
Section 1C Engine Cooling for testing.
• Engine coolant level.
• Engine coolant leakage.
• Cooling fan belt slippage.
• Cooling fan clutch working.
• Thermostat working.
• Water pump working.
• Radiator clogging.
• Modified cooling system which is less cooling capacity.
Engine Control System (4JJ1)
Action
1A-347