Question

Technician A states that most DPF regeneration in highway diesel engines should occur as passive regeneration. Technician B states that DPF active regeneration cycles usually require the

injection of fuel upstream from the DPF. Who is correct?
a) Technician A only
b) Technician B only
c) Both A and B
d) Neither A nor B

Answer 1

Both Technician A and Technician B are correct. Passive regeneration occurs in highway diesel engines, while active regeneration requires fuel injection upstream from the DPF.

Step-by-step explanation:

Both Technician A and Technician B are correct.

Technician A is correct because most DPF regeneration in highway diesel engines does occur as passive regeneration. Passive regeneration happens when the normal exhaust temperatures of the engine are sufficient to burn off the accumulated soot in the DPF without any additional fuel injection.

Technician B is correct because DPF active regeneration cycles usually do require the injection of fuel upstream from the DPF. Active regeneration occurs when the exhaust temperatures are not high enough to burn off the soot, so a small amount of fuel is injected into the engine to increase the exhaust temperatures and initiate the regeneration process.