Dodge Sprinter 2006 Manual page 420

GEN ERAL I N FORM AT I ON
3.2.2 ECM OPERA TING MODES
As in pu t sign a ls t o t h e E CM ch a n ge, t h e E CM
a dju st s it s r espon se t o t h e ou t pu t devices. F or
exa m ple, t h e E CM m u st ca lcu la t e a differ en t fu el
qu a n t it y a n d fu el t im in g for en gin e idle con dit ion
t h a n it wou ld for a wide open t h r ot t le con dit ion .
Th er e a r e sever a l differ en t m odes of oper a t ion t h a t
det er m in e h ow t h e E CM r espon ds t o t h e va r iou s
in pu t sign a ls.
Ignition Switch On (Engine Off)
Wh en t h e ign it ion is t u r n ed on t h e E CM a ct iva t es
t h e glow plu g r ela y for a t im e per iod t h a t is det er-
m in ed by en gin e coola n t t em per a t u r e, in t a ke a ir
t em per a t u r e a n d ba t t er y volt a ge.
Engine Start-Up Mode
Th e E CM u ses t h e in t a ke a ir t em per a t u r e sen sor,
en gin e t em per a t u r e sen sor a n d t h e cr a n ksh a ft po-
sit ion sen sor (en gin e speed) in pu t s t o det er m in e
fu el in ject ion qu a n t it y.
Normal Driving Modes
E n gin e idle, wa r m -u p, a cceler a t ion , deceler a t ion
a n d wide open t h r ot t le m odes a r e con t r olled ba sed
on a ll of t h e sen sor in pu t s t o t h e E CM. Th e E CM
u ses t h ese sen sor in pu t s t o a dju st fu el qu a n t it y a n d
fu el in ject or t im in g. E GR va lve con t r ol is per for m ed
u sin g feedba ck fr om t h e oxygen sen sor. An oxygen
sen sor is loca t ed in t h e exh a u st m a n ifold t o sa m ple
oxygen con t en t exit in g t h e en gin e cylin der s. Th e
E CM u ses t h e O2 sen sor, a lon g wit h ot h er sen sor
in pu t s, t o gover n t h e a m ou n t of exh a u st ga s r ecir-
cu la t ion t o r edu ce H C (H ydr oCa r bon s) a n d CO
(Ca r bon Mon oxide). E n gin e coola n t is r ou t ed
t h r ou gh t h e ba se of t h e E GR va lve t o pr ovide
a ddit ion a l coolin g of t h e exh a u st ga s, wh ich fu r t h er
h elps t h e r edu ct ion s of em ission s. Th e E GR va lve
h a s a self-clea n in g fu n ct ion . Wh en t h e en gin e is
sh u t off, t h e E GR va lve r ot a t es t wice t o r edu ce
ca r bon deposit s a t t h e va lve sea t .
Overheat Production Mode
If t h e en gin e t em per a t u r e is a bove 105°C (221°F )
a n d veh icle speed is a bove 40 km /h (25 MP H ) t h e
E CM will lim it fu el qu a n t it y for en gin e pr ot ect ion .
Limp-In Mode
Th e E CM u t ilizes differ en t degr ees of en gin e
lim p-in . Th e E CM is a ble t o lim it en gin e r pm ,
en gin e power ou t pu t (t u r bo boost r edu ct ion ), a ct i-
va t e en gin e coolin g fa n or a ll of t h ese fu n ct ion s
ba sed on t h e t ype of fa u lt t h a t is det ect ed. Cr it ica l
en gin e per for m a n ce fa u lt s su ch a s a cceler a t or peda l
posit ion sen sor fa u lt will r esu lt in a fixed idle speed
of a ppr oxim a t ely 680 r pm r ega r dless of a ct u a l peda l
posit ion . Ot h er less cr it ica l fa u lt s will r esu lt in
power r edu ct ion t h r ou gh ou t t h e fu ll r a n ge of dr iv-
in g con dit ion s.
Overspeed Detection Mode
If t h e E CM det ect s en gin e RP M t h a t exceeds
5200 RP M, t h e E CM will set a DTC in m em or y,
lim it en gin e RP M t o n o m or e t h a n 2500 RP M, a n d
illu m in a t e t h e MIL u n t il t h e DTC is clea r ed.
After-Run Mode
Th e E CM t r a n sfer s RAM in for m a t ion t o ROM
a n d per for m s a n In pu t /Ou t pu t st a t e ch eck.
3.2.3 MONITORED CIRCUITS
Th e E CM is a ble t o m on it or a n d iden t ify m ost
dr ivea bilit y r ela t ed t r ou ble con dit ion s. Som e cir-
cu it s a r e dir ect ly m on it or ed t h r ou gh E CM feedba ck
cir cu it r y. In a ddit ion , t h e E CM m on it or s t h e volt a ge
st a t e of som e cir cu it s a n d com pa r es t h ose st a t es
wit h expect ed va lu es. Ot h er syst em s a r e m on it or ed
in dir ect ly wh en t h e E CM con du ct s a r a t ion a lit y t est
t o iden t ify pr oblem s.
Alt h ou gh m ost su bsyst em s of t h e en gin e con t r ol
m odu le a r e eit h er dir ect ly or in dir ect ly m on it or ed,
t h er e m a y be occa sion s wh en dia gn ost ic t r ou ble
codes a r e n ot im m edia t ely iden t ified. F or a t r ou ble
code t o set , a specific set of con dit ion s m u st occu r
a n d u n less t h ese con dit ion s occu r, a DTC will n ot
set .
3.2.4 SKREEM OVERVIEW
Th e sen t r y key r em ot e en t r y m odu le syst em
(SKRE E M) is design ed t o pr even t u n a u t h or ized
veh icle oper a t ion . Th e syst em con sist s of a sen t r y
key r em ot e en t r y m odu le (SKRE E M), ign it ion
key(s) equ ipped wit h a t r a n spon der ch ip a n d t h e
E CM. Wh en t h e ign it ion swit ch is t u r n ed on , t h e
SKRE E M in t er r oga t es t h e ign it ion key. If t h e ign i-
t ion key is Va lid or In va lid, t h e SKRE E M sen ds a
m essa ge t o t h e E CM in dica t in g ign it ion key st a t u s.
Upon r eceivin g t h is m essa ge t h e E CM will t er m i-
n a t e en gin e oper a t ion or a llow t h e en gin e t o con -
t in u e t o oper a t e.
3.2.5 SKREEM ON-BOARD DIAGNOSTICS
Th e SKRE E M h a s been pr ogr a m m ed t o t r a n sm it
a n d m on it or m a n y differ en t coded m essa ges a s well
a s CAN Bu s m essa ges. Th is m on it or in g is ca lled
On -Boa r d Dia gn ost ics. Cer t a in cr it er ia m u st be m et
for a DTC t o be en t er ed in t o SKRE E M m em or y. Th e
cr it er ia m a y be a r a n ge of; in pu t volt a ge, CAN Bu s
m essa ge or coded m essa ges t o t h e SKRE E M. If a ll
t h e cr it er ia for m on it or in g a cir cu it or fu n ct ion a r e
m et a n d a fa u lt is det ect ed, a DTC will be st or ed in
t h e SKRE E M m em or y a n d t h e START E RROR in di-
ca t or will be t u r n ed on in t h e in st r u m en t clu st er.
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