21503936 | Genuine Volvo® Aftertreatment DPF Injector

• Regenerate the Diesel Particulate Filter (DPF):
  • The injector sprays diesel fuel into the exhaust stream.
  • The fuel reaches the Diesel Oxidation Catalyst (DOC), where it oxidizes and raises the exhaust temperature.
  • The higher temperature burns the soot trapped in the DPF, converting it into ash.
• Prevent DPF clogging:
  • Regular regeneration keeps soot from accumulating.
  • This maintains exhaust flow and helps avoid excessive backpressure.
• Maintain engine performance:
  • A clean DPF allows the engine to breathe properly.
  • This helps prevent power loss and engine derate caused by a restricted exhaust.
• Reduce emissions:
  • By enabling proper DPF regeneration, the injector helps the vehicle meet emissions regulations by reducing particulate matter (soot).

1. Frequent or failed DPF regenerations

• Truck tries to regen more often than normal
• Regeneration cycles fail or don’t complete
• Parked regen may be requested repeatedly

2. DPF warning lights

• “DPF Full” or “Exhaust System” warning on dash
• Check Engine Light (CEL) related to aftertreatment system

3. Engine derate (loss of power)

• Truck goes into reduced power mode
• Speed or torque limitations activated
• Often happens when soot level becomes too high

4. High soot or backpressure readings

• Diagnostic tool shows rapid soot accumulation
• Elevated exhaust backpressure in DPF

5. Excessive fuel consumption

• Increased fuel use due to repeated regen attempts
• Long or unusually frequent active regenerations

6. Fault codes (common examples)
You may see codes such as:

• Aftertreatment fuel dosing valve performance issues
• DPF regeneration insufficient temperature
• Hydrocarbon doser circuit faults
• DOC outlet temperature not reaching target

7. White smoke or fuel smell during regen (sometimes)

• Incomplete atomization of injected fuel
• Fuel may not fully combust in the DOC

8. Soot clogging in DPF despite regens

• DPF continues to load even after regen attempts
• Indicates poor or no fuel dosing into exhaust stream