User Manual

Chapter 13
BOSCH HDI EDC 15C2 INJECTION SYSTEM AND PARTICLE FILTER
115
D - CORRECTION OF THE LOAD LEVELS DEPENDING ON THE AMOUNT OF
CERINE
The cerine in the fuel:
• is not burnt with the soot,
• builds up on the walls of the particle filter.
The injection ECU therefore permanently adapts its cartographic maps
depending on the amount of cerine accumulated in the particle filter.
E - EFFECT OF DRIVING CONDITIONS ON THE PRESSURE DIFFERENTIAL
The change in pressure differential also depends on the following parameters:
• fuel consumption (fuel + additive),
• vehicle driving conditions (activation of post-injection),
• exhaust gas temperature,
• exhaust gas speed in the particle filter.
SDI042D
F
G
E E
D D
g
h
h
g
D - Volume flow of exhaust gases (l/h)
E - Pressure differential (mbar)
F - Road or motorway type driving (before regeneration)
G - Urban type driving (before regeneration)
h - Filtered exhaust gases
g - Deposits (cerine, soot, unburned hydrocarbons, oil deposits, etc)
Example F:
• the deposits collect at the bottom of the particle filter,
• the gases pass easily through the channels and the pressure differential is low.
Example G:
• the deposits collect in a stratified layer on the channels,
• the gases have problems passing through the channels and the pressure
differential is high.
Warning: For the same amount of cerine and for the same vehicle mileage, the
differential pressure may vary.
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