Programming The Powertrain Control Module - Chrysler Sebring 2005 Service Manual

t est is com plet ed, t h e SKIM en er gizes t h e a n t en n a
(t h is a ct iva t es t h e t r a n spon der ch ip) a n d sen ds a
ch a llen ge t o t h e t r a n spon der ch ip. Th e t r a n spon der
ch ip r espon ds t o t h e ch a llen ge by gen er a t in g a n
en cr ypt ed r espon se m essa ge u sin g t h e followin g:
S e c re t Ke y - Th is is a n elect r on ica lly st or ed
va lu e (iden t ifica t ion n u m ber ) t h a t is u n iqu e t o ea ch
SKIS. Th e secr et key is st or ed in t h e SKIM, P CM
a n d a ll ign it ion key t r a n spon der s.
Ch a lle n g e - Th is is a r a n dom n u m ber t h a t is
gen er a t ed by t h e SKIM a t ea ch ign it ion key cycle.
Th e secr et key a n d ch a llen ge a r e t h e t wo va r i-
a bles u sed in t h e a lgor it h m t h a t pr odu ces t h e
en cr ypt ed r espon se m essa ge. Th e t r a n spon der u ses
t h e cr ypt o a lgor it h m t o r eceive, decode a n d r espon d
t o t h e m essa ge sen t by t h e SKIM. Aft er r espon din g
t o t h e coded m essa ge, t h e t r a n spon der sen ds a
t r a n spon der I.D. m essa ge t o t h e SKIM. Th e SKIM
com pa r es t h e t r a n spon der I.D. t o t h e a va ila ble va lid
key codes in t h e SKIM m em or y (8 key m a xim u m a t
a n y on e t im e). Aft er va lida t in g t h e key ign it ion t h e
SKIM sen ds a P CI Bu s m essa ge ca lled a Seed
Requ est t o t h e en gin e con t r oller t h en wa it s for a
P CM r espon se. If t h e P CM does n ot r espon d, t h e
SKIM will sen d t h e seed r equ est a ga in . Aft er t h r ee
fa iled a t t em pt s t h e SKIM will st op sen din g t h e seed
r equ est a n d st or e a t r ou ble code. If t h e P CM sen ds
a seed r espon se, t h e SKIM sen ds a va lid/in va lid key
m essa ge t o t h e P CM. Th is is a n en cr ypt ed m essa ge
t h a t is gen er a t ed u sin g t h e followin g:
VIN - Veh icle Iden t ifica t ion Nu m ber
S e e d - Th is is a r a n dom n u m ber t h a t is gen er a t ed
by t h e P CM a t ea ch ign it ion key cycle.
Th e VIN a n d seed a r e t h e t wo va r ia bles u sed in
t h e r ollin g code a lgor it h m t h a t en cr ypt s t h e va lid/
in va lid key m essa ge. Th e P CM u ses t h e r ollin g code
a lgor it h m t o r eceive, decode a n d r espon d t o t h e
va lid/in va lid key m essa ge sen t by t h e SKIM. Aft er
sen din g t h e va lid/in va lid key m essa ge t h e SKIM
wa it s 3.5 secon ds for a P CM st a t u s m essa ge fr om
t h e P CM. If t h e P CM does n ot r espon d wit h a va lid
key m essa ge t o t h e SKIM, a fa u lt is det ect ed a n d a
t r ou ble code is st or ed.
Th e SKIS in cor por a t es a VTSS LE D loca t ed on
t h e in st r u m en t pa n el u pper cover. Th e LE D r e-
ceives swit ch ed ign it ion volt a ge a n d is h a r dwir ed t o
t h e body con t r ol m odu le. Th e LE D is a ct u a t ed wh en
t h e SKIM sen ds a P CI Bu s m essa ge t o t h e body
con t r oller r equ est in g t h e LE D on . Th e body con t r ol-
ler t h en pr ovides t h e gr ou n d for t h e LE D. Th e
SKIM will r equ est VTSS LE D oper a t ion for t h e
followin g:
– bu lb ch ecks a t ign it ion on
– t o a ler t t h e veh icle oper a t or t o a SKIS m a l-
fu n ct ion
– cu st om er key pr ogr a m m in g m ode
GEN ERAL I N FORM AT I ON
F or a ll fa u lt s except t r a n spon der fa u lt s a n d VTSS
LE D r em a in s on st ea dy. In t h e even t of a t r a n spon -
der fa u lt t h e LE D fla sh es a t a r a t e of 1 H z (on ce per
secon d). If a fa u lt is pr esen t t h e LE D will r em a in on
or fla sh in g for t h e com plet e ign it ion cycle. If a fa u lt
is st or ed in SKIM m em or y wh ich pr even t s t h e
syst em fr om oper a t in g pr oper ly, t h e P CM will a llow
t h e en gin e t o st a r t a n d r u n (for 2 secon ds) u p t o six
t im es. Aft er t h e sixt h a t t em pt , t h e P CM disa bles
t h e st a r t er r ela y u n t il t h e fa u lt is cor r ect ed.
3.2.9 PROGRAMMING THE POWERTRAIN
CONTROL MODULE
Im p o rta n t N o te : Befor e r epla cin g t h e P CM for a
fa iled dr iver, con t r ol cir cu it or gr ou n d cir cu it , be
su r e t o ch eck t h e r ela t ed com pon en t /cir cu it in t eg-
r it y for fa ilu r es n ot det ect ed du e t o a dou ble fa u lt in
t h e cir cu it . Most P CM dr iver /con t r ol cir cu it fa ilu r es
a r e ca u sed by in t er n a l fa ilu r e t o com pon en t s (i.e.
12-volt pu ll-u ps, dr iver s a n d gr ou n d sen sor s). Th ese
fa ilu r es a r e difficu lt t o det ect wh en a dou ble fa u lt
h a s occu r r ed a n d on ly on e DTC h a s set .
NOTE: If the PCM and the SKIM are replaced
at the same time, program the VIN into the
PCM first. All vehicle keys will then need to
be replaced and programmed to the new
SKIM.
Th e SKIS Secr et Key is a n I.D. code t h a t is
u n iqu e t o ea ch SKIS. Th is code is pr ogr a m m ed a n d
st or ed in t h e SKIM, en gin e con t r oller a n d t r a n spon -
der ch ip (ign it ion key). Wh en r epla cin g t h e P CM it
is n ecessa r y t o pr ogr a m t h e secr et key in t o t h e
P CM.
NOTE: After replacing the PCM, you must
reprogram pinion factor.
1. Tu r n t h e ign it ion on (t r a n sm ission in pa r k/
n eu t r a l).
2. Use t h e DRBIII
SKIM t h en MISCE LLANE OUS.
3. Select P CM RE P LACE D.
4. E n t er secu r ed a ccess m ode by en t er in g t h e veh i-
cle fou r-digit P IN.
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a n d select TH E F T ALARM,