Diagnostics - Mazda 6 Facelift 2005 Training Manual

Diesel Engines

Diagnostics

•
Since the filter itself creates a certain resistance in the exhaust gas flow, the signal of the
DPF differential pressure sensor is also used to determine the filter condition.
X Exhaust-gas volume flow
1 Blocked condition of filter
2 Overloaded condition of filter
3 Loaded condition of filter
4 Intermediate condition of filter
•
If the value measured by the DPF differential pressure sensor is above a certain limit, the
DPF is recognized as being blocked. Then the PCM stores a corresponding DTC,
illuminates the MIL (Malfunction Indicator Light) and activates the limp home mode.
•
The blocking of the DPF is often as a result of excessive soot emission by the engine
(e.g. due to EGR valve stuck open, leak in the intake-air system etc.) or can be attributed
to multiple failed regeneration processes. To rectify this concern, a manual regeneration
should be carried out using WDS (refer to the section "Control System, Service and
Repair").
01-66
Y Differential pressure
5 Regenerated condition of filter
6 Damaged condition of filter
7 Differential pressure limit
Service Training Mazda6 Facelift
Engine
M6FL_01062