Dodge Sprinter 2006 Manual page 2149

VA
1 - EGR VALVE
2 - COOLANT PASSAGE
VALV E
DESCRIPTION
E xh a u st ga s r ecir cu la t ion r edu ces t h e qu a n t it y of
fr esh a ir su pplied t o t h e cylin der s per st r oke wit h ou t
h a vin g t o t h r ot t le t h e a ir su pply. E xh a u st ga s is
r ecir cu la t ed du r in g a ll en gin e speed a n d en gin e loa d
con dit ion s. As a r esu lt , em ission s a r e r edu ced. If a
qu a n t it y of exh a u st ga s is m ixed wit h t h e a ir t h a t is
t o be u sed t o bu r n t h e fu el in t h e cylin der s, t h e oxy-
gen con t en t is r edu ced beca u se t h e exh a u st ga s is
low in oxygen . Th e r esu lt is t h a t t h e com bu st ion r a t e
is r edu ced, a s is t h e com bu st ion t em per a t u r e. Th is
r edu ces t h e qu a n t it y of NOx t h a t a r e em it t ed in t h e
exh a u st ga s. (F ig. 2).
Th e E CM power su pply r ela y h a s a power off dela y
fea t u r e. Th e r ela y is power ed off a ppr oxim a t ely 15
secon ds a ft er t h e ign it ion swit ch is t u r n ed off. Th is
a llows for t h e self-clea n in g fu n ct ion of t h e E GR va lve
a n d a fu n ct ion ch eck of t h e sen sor s for dia gn osis pu r-
poses.
Fig. 1 EGR AND COOLER
3 - COOLING FINS
4 - EXHAUST GAS PASSAGE
EXHAUST GAS RECIRCULA TION 25 - 5