DPF® Regeneration Description
Precautions: General safety (00)
General Description
After the specified period which varies depending on the driving condition, the DPF® must be regenerated by burning off the diesel PM accumulated inside.
The regeneration must be carried out using one of the following methods, depending on the amount or condition of diesel PM accumulation.
•Natural Regeneration
•Forced Regeneration without Speed Request
•Forced Regeneration with Speed Request
•After-sales Regeneration
•Forced Regeneration without Speed Request
•Forced Regeneration with Speed Request
•After-sales Regeneration
During the “Forced Regeneration without Speed Request”, “Forced Regeneration with Speed Request”, and “After-sales Regeneration”, ECM performs a control to cause a post-injection of unburned fuel during the power stroke of each piston to deliver unburned fuel to the catalytic converter, thereby heating up the catalytic converter and bringing EGT to 570 °C (1,058 °F) or higher.
Natural Regeneration
“Natural regeneration” is performed according to the exhaust gas temperature in the normal driving condition. The driver will not find that the vehicle is in “Natural regeneration”.
Forced Regeneration without Speed Request
“Forced Regeneration without Speed Request” is activated by ECM automatically when the DPF® clogging becomes approx. 70 to 135% (depending on vehicle speed).
In this operation, as no warning light comes on, the driver will not recognize that “Forced Regeneration” is activated while driving.
NOTE:
Even if vehicle is under idling condition, forced regeneration without speed request is activated according to the DPF® clogging.
In this state, the driver will recognize the activation by the increase of idling engine speed (+50 rpm).
Forced Regeneration with Speed Request
“Forced Regeneration with Speed Request” is a special DPF® regeneration that requires driver’s intervention, i.e., accelerating the vehicle to a speed high enough for regeneration. When diesel PM has accumulated to 135% or more, or regeneration interruption history becomes 6 times or more, ECM recognizes the state as “being impossible to continue driving further without forcedly regenerating DPF®”.
Then ECM causes the DPF® warning light in the combination meter to light up to give the driver a prompt to increase the vehicle speed to 50 km/h (31 mile/h) or higher, or accelerate the engine to more than 2,000 rpm, until the DPF® warning light goes out (max. 25 min.).
Once the driver starts accelerating and the vehicle or engine reaches the requested speed, ECM activates the forced regeneration like with the “Forced Regeneration without Speed Request” and continues the regeneration until the amount of diesel PM inside the DPF® decreases to a normal value.
If the engine is stopped intermediately during the “Forced Regeneration with Speed Request”, ECM warns the driver that too much diesel PM remains in the DPF® by causing the DPF® warning light to light up.
NOTE:
Even if vehicle is under idling condition, forced regeneration with speed request is activated according to the DPF® clogging.
In this state, the driver will recognize the activation by the increase of idling engine speed (+50 rpm).
After-Sales Regeneration
If diesel PM has accumulated to 160% or more, ECM detects DTC P24A4.
If the gas flow resistance of DPF® calculated by ECM exceeds 0.065 kPa/m3/h (0.00066 kgf/cm2/m3/h, 0.0094 psi/m3/h, 0.65 mbar/m3/h), ECM detects DTC P1206. Furthermore, if the calculated resistance exceeds 0.12 kPa/m3/h (0.00122 kgf/cm2/m3/h, 0.0174 psi/m3/h, 1.2 mbar/m3/h), ECM detects DTC P2002.
If DTC P1206 or P24A4 is detected:
•ECM turns on MIL in the combination meter to inform that the DPF® would have been fully loaded with diesel PM.
•ECM limits the driving performance slightly and cancels “Forced Regeneration” to prevent the DPF® from melt and cracking.
•ECM turns off DPF® warning light.
•In this situation, “After-sales regeneration” should be performed.
•ECM limits the driving performance slightly and cancels “Forced Regeneration” to prevent the DPF® from melt and cracking.
•ECM turns off DPF® warning light.
•In this situation, “After-sales regeneration” should be performed.
For the method of after-sales regeneration, refer to DPF® After-Sales Regeneration:D16AA.
If DTC P2002 is detected:
•ECM turns on MIL in the combination meter to inform that the DPF® would have been fully loaded with diesel PM.
•ECM limits the driving performance slightly and cancels “Forced Regeneration” to prevent the DPF® from melt and cracking.
•ECM turns off DPF® warning light.
•In this situation, DPF® will have to be replaced.
•ECM limits the driving performance slightly and cancels “Forced Regeneration” to prevent the DPF® from melt and cracking.
•ECM turns off DPF® warning light.
•In this situation, DPF® will have to be replaced.
DPF® state table
| DPF® clogging | DPF® warning light | MIL | DTC | DPF® flow resistance | Forced regeneration or after-sales regeneration | Description |
|---|---|---|---|---|---|---|
| Approx. 0 to 70% | OFF | OFF | — | — | Not approved | DPF® is fully regenerated. |
| Approx. 70 to 135% | OFF | OFF | — | — | Forced regeneration without speed request | DPF® is a little full. |
| Approx. 135% or more | ON | OFF | — | — | Forced regeneration with speed request | DPF® is some full. |
| Approx. 160% or more | OFF | ON | P24A4 | — | After-sales regeneration | DPF® is almost full and slight limitation is implemented. |
| OFF | ON | P1206 | 0.065 to 0.12 kPa/m3/h (0.00066 to 0.00122 kgf/cm2/m3/h, 0.0094 to 0.0174 psi/m3/h, 0.65 to 1.2 mbar/m3/h) | After-sales regeneration | DPF® is full and slight limitation is implemented. | |
| OFF | ON | P2002 | 0.12 kPa/m3/h (0.0012 kgf/cm2/m3/h, 0.0174 psi/m3/h, 1.2 mbar/m3/h) or more | Not approved | DPF® is clogged and slight limitation is implemented. |
NOTE:
Values in the “DPF® clogging” and “DPF® gas flow resistance” columns can be monitored using the Data List function of SUZUKI scan tool.
Engine Oil Degradation Description
The DPF® regeneration conditions are seldom met during a low-speed, short-distance drive. This prevents ECM from completing the process of “Natural Regeneration” or “Forced Regeneration without Speed Request”.
As a result, DPF® is incompletely regenerated and collected diesel PM is not sufficiently eliminated.
If a low-speed, short-distance drive is repeated successively, larger amount of unburned diesel PM accumulates more frequently.
Under such a condition, ECM repeats DPF® regeneration control.
If the DPF® regeneration is repeated, unburned fuel injected by post-injection dilutes engine oil. For further details of engine oil dilution, refer to Oil Life Monitoring System Description:D16AA.
The more the engine oil is diluted with unburned fuel, the more the viscosity of the oil decreases, and this causes the oil level in the oil pan to rise.
As an excessive drop in engine oil viscosity and a rise in engine oil level beyond the specified level could cause serious damage to the engine, oil level check should be performed if the above condition is suspected, referring to Engine Oil Level Check:D16AA. If the engine oil level exceeds the upper limit mark on the dipstick by more than 15 mm (0.59 in.), the oil level should be adjusted to correct level.