The ECM detects the PM accumulation status from the exhaust differential pressure sensor. The exhaust differential pressure sensor changes the signal voltage in accordance with changes in the exhaust gas pressure difference in the front and rear of the DPD filter. If the exhaust differential pressure sensor reaches a certain level of PM accumulation or reaches a certain running distance, DPD automatic regeneration starts. If automatic regeneration cannot be completed for some reason, the DPD operator regeneration indicator light in the instrument panel cluster will flash to request the driver to perform DPD regeneration. Once regeneration is started, it must be completed within a predetermined amount of time. After completing DPD regeneration, filter purification status is determined from the DPD exhaust differential pressure. If the ECM detects excessive PM accumulation, the ECM does not start regeneration because the temperature of the regeneration process becomes so high that DPD filter melting occurs and combustion becomes uncontrollable.
If DPD regeneration is not started, the DTC that suppressed the regeneration control is set. If no DTC is set, observe the Vehicle Speed, Accelerator Pedal Position (APP), and Neutral Switch parameters related to DPD regeneration control on the scan tool.