Regeneration takes more time than expected. Or, it takes longer than before.
Inspect the fuel quality.
Observe the scan tool data list.
Check for related Service Bulletin.
Verify the driver's driving habits and conditions.
Check if the idling time is too long during DPD regeneration.
Check if driving at lower speed is frequent during DPD regeneration.
Check if the engine operating time is short during DPD regeneration.
Check if the vehicle driving time is short during DPD regeneration.
Check if switching the accelerator pedal ON/OFF is frequent during DPD regeneration.
Check if the work environment temperature is excessively high during DPD regeneration.
Inspect for incorrect piping or disconnection of the differential pressure hose and pipe.
{Installation direction of the differential pressure hose is specified.}
Inspect for clogging, collapsing, or twisting of the differential pressure hose and pipe.
Inspect for incorrect installation of the exhaust differential pressure sensor.
Inspect the exhaust differential pressure sensor for damage.
Inspect for dirt or foreign material blocking the inlet of the exhaust differential pressure sensor.
Observe the Exhaust Differential Pressure parameter and check for an exhaust differential pressure sensor malfunction or for a slow reaction.
Check the exhaust gas temperature sensor at various temperatures, and inspect for the possibility of sensor malfunction.
Inspect the fuel system problem.
Inspect the engine coolant level.
Inspect for engine coolant leakage.
Inspect for cooling fan belt slip.
Inspect the operation of the cooling fan clutch.
Inspect the operation of the thermostat.
Inspect the operation of the water pump.
Inspect the radiator for clogging.
Inspect whether the cooling level of the cooling system is low due to modifications.
Inspect the air cleaner, air intake duct, and intercooler for clogging, holes, or leakage.
Inspect for any condition that restricts flow within the turbocharger intake duct.
Inspect for a stuck intake throttle valve.
Inspect the inlet manifold for clogging or air leakage.
Inspect the air intake system for modification.
Inspect the MAF sensor for dirt or damage.
Inspect the turbocharger turbine wheel, shaft, or compressor wheel for wear or damage.
Inspect whether the exhaust system flow is restricted.
Inspect for a missing or damaged exhaust system gasket.
Inspect for exhaust gas leakage from the exhaust pipe, gasket, DPD body, exhaust temperature sensor, or exhaust differential pressure sensor hose or pipe.
Inspect the exhaust system for modification.
Inspect for excessive ash deposits on the DPD filter.
Inspect the DPD filter for damage, cracks, melting, or excessive deposits.
Inspect the oxidation catalyst for damage, cracks, melting, or excessive deposits.
If any excessive white smoke is observed in the regeneration process, the oxidation catalyst may be deteriorated or damaged.
Check for possible factor of overheat.
Inspect the operation of the air conditioner.