Page 49 of 1954
OnStar Control Unit Input Test
1. Remove the rear seat (Refer to the '96 - '01 3.5RL Service Manual, P/N 61SZ305, for the items not shown in this sec-
tion).
2. Disconnect the 32P connectors from the OnStar control unit.
3. Inspect the connector and socket terminals to be sure they are all making good contact.
• If the terminals are bent, loose or corroded, repair them as necessary, and recheck the system.
• If the terminals look OK, make the following input tests at the connector.
— If any test indicates a problem, find and correct the cause, then recheck the system.
— If all the input tests prove OK, the control unit must be faulty; replace it.
32P CONNECTOR A (red):
Wire side of female
terminals
32P CONNECTOR B (blue):
Wire side of female terminalsProCarManuals.com
Page 250 of 1954

Navigation Syste m
Sympto m Troubleshootin g (cont'd )
Picture i s missin g a red/green/blu e colo r o r
tone , o r rollin g pictur e
Diagnosti c Test : Monito r Chec k
NOTE:
• Alway s chec k th e connector s fo r poo r connection s o r
loos e terminals .
• Befor e troubleshooting , ge t th e navigatio n syste m
anti-thef t codes .
• Afte r troubleshooting , ente r th e navigatio n syste m
anti-thef t codes .
1 . G o int o Diagnosti c mod e an d us e "RG B Color "
diagnosti c unde r
Monito r Check (see pag e 23-41 ).
Are the red, green, and blue colored circles
shown?
YES—Th e syste m is OK .
NO—G o t o ste p 2 .
2 . Tur n th e ignitio n switc h t o OFF .
3 . Disconnec t th e navigatio n uni t connecto r A (20P )
an d displa y uni t connecto r B (20P) .
4 . Chec k fo r loos e terminal s a t navigatio n uni t con -
necto r A (20P ) an d displa y uni t connecto r B (20P) .
Are there loose terminals?
YES—Repai r th e terminal .
NO—G o t o ste p 5 . 5
. Chec k fo r continuit y betwee n th e appropriat e termi -
nal s o f navigatio n uni t connecto r A (20P ) t o displa y
uni t connecto r B (20P ) base d o n th e missin g color(s) .
Missin g
colo r
Blue
Gree n
Red
Navigatio n
unit
connecto r A
(20P )
A11
A2
A 1
Displa y uni t
connecto r B
(20P )
B18
B9
B8
Wir e
colo r
YEL
RE D
WH T
NAVIGATIO N UNI T CONNECTO R A (20P )
DISPLA Y UNI T CONNECTO R B (20P )
Wire sid e o f femal e terminal s
Is there continuity?
YES—G o to ste p 6 .
NO—Ther e is a n ope n i n th e circui t betwee n th e dis -
pla y uni t an d th e navigatio n unit . Chec k fo r poo r con -
nection s o r loos e terminal s a t th e displa y an d naviga -
tio n units . I f a poo r connectio n o r loos e termina l i s
found , replac e th e affecte d shielde d harness .
ProCarManuals.com
Page 251 of 1954
6. Check for continuity between the appropriate termi-
nals of navigation unit connector A (20P) and display
unit connector B (20P) based on the missing color(s).
Missing Navigation
color unit connector
A
(20P)
Blue A11
Green A2
Red A1
Display unit
connector B
(20P)
B10,
B20
B10,
B20
B10,
B20
NAVIGATION UNIT CONNECTOR A (20P)
Wire side of female terminals
DISPLAY UNIT CONNECTOR B I20PI
Wire side of female terminals
Is there continuity?
YES—There is a short to body ground in the circuit
between the display unit and the navigation unit.
Replace the affected shielded harness.
NO—Replace the navigation unit. If the problem is
still unresolved, replace the display unit.ProCarManuals.com
Page 252 of 1954

Picture ha s lines/othe r issue s
Diagnosti c Check : Monito r Chec k
NOTE :
• Alway s chec k th e connector s fo r poo r connection s o r
loos e terminals .
• Befor e troubleshooting , ge t th e navigatio n syste m
anti-thef t codes .
• Afte r troubleshooting , ente r th e navigatio n syste m
anti-thef t codes .
1. Chec k fo r electroni c aftermarke t accessorie s (passive -
ly hidden ) mounte d nea r th e displa y uni t o r th e navi -
gation unit .
Are there any electronic accessories?
YES—Disabl e th e accessories , an d recheck .
NO—Go t o ste p 2 .
2. Star t u p th e navigatio n picture .
Is the picture scrolling horizontally (left to right or
right to left)?
YES—Chec k fo r a n ope n o r shor t t o groun d i n th e C
SI G wir e fro m navigatio n uni t connecto r A (20P ) ter -
mina l No . 1 2 to displa y uni t connecto r B (20P ) termi -
nal No . 18 . Als o chec k fo r a shor t t o groun d betwee n
display uni t connecto r B termina l No . 1 9 an d termina l
No. 20 .
NO—G o t o ste p 3 .
3. G o int o th e Diagnosti c mod e an d us e "RG B Color "
diagnosti c unde r Monito r Chec k (se e pag e 23-41 ).
Is the picture missing a red, green or blue color?
YES—D o th e troubleshootin g fo r th e pictur e is miss -
ing a red , gree n o r blu e colo r o r ton e (se e pag e 23 -28) .
NO—G o t o ste p 4 .
(cont'd )
ProCarManuals.com
Page 266 of 1954

Monitor Chec k
Overvie w o f displa y uni t
• Th e displa y uni t communicate s wit h th e navigatio n
uni t ove r it s ow n GA-Ne t bus . Informatio n i s sen t t o
th e navigatio n uni t wheneve r th e use r activate s th e
touc h screen , o r har d buttons . Informatio n sen t b y
th e navigatio n uni t t o th e displa y uni t include s com -
mand s t o contro l th e LC D bac k light .
• Th e navigatio n uni t als o send s navigatio n informa -
tion to th e scree n usin g th e Red , Green , Blue , an d
Composit e Vide o signals .
• Th e displa y uni t i s protecte d b y th e securit y syste m
b y daisy-chainin g th e securit y signa l throug h it , an d
the n passin g th e signa l t o th e audi o unit .
• Th e illuminatio n inpu t fro m th e gaug e brightnes s
contro l provide s bac k lightin g fo r th e har d button s
surroundin g th e screen .
• Th e displa y uni t als o communicate s wit h th e climat e
contro l modul e to se t th e A/ C mode , an d fa n speed .
Thes e screen s allo w troubleshootin g o f th e displa y unit .
Touc h th e men u ite m yo u wan t t o troubleshoot , an d fol -
low the diagnosti c instructions .
RGB Colo r
This scree n verifie s tha t th e displa y uni t i s receivin g th e
vide o (R , G , B an d Composit e sync ) signal s properly .
Th e thre e primar y color s shoul d al l b e show n withou t
distortion . Th e combinatio n o f al l thre e shoul d produc e
a centra l whit e section . I f an y o f th e color s ar e missing ,
troubleshoo t fo r th e colo r signa l (se e pag e 23-28 ). I f th e
pictur e ha s line s i n it o r scroll s horizontally , o r vertically ,
troubleshoo t fo r a Composit e syn c proble m (se e pag e
23-29 ).
Gra y Ton e
Thi s scree n diagnose s problem s wit h contrast . Yo u
shoul d b e abl e to se e th e change s fro m ba r t o ba r
acros s th e scale . I t i s norma l fo r th e 2 bar s o n eithe r sid e
t o appea r th e same .
White Raste r
The entir e displa y mus t b e show n i n white .
ProCarManuals.com
Page 283 of 1954
1999 Model
Vehicle Identification Number
Transmission Number
*1: U.S. model only
Engine Number
C35A1 - 4000001
Vehicle Identification Number
and Federal Motor Vehicle
Safety Standard Certification.
Vehicle Identification Number
and Canadian Motor Vehicle
Safety Standard Certification.
COLOR LABEL
INT. COLOR
TYPE F
EXT. COLOR
G-97P
KA SZ3 A6 C
Paint Code
Paint Code
Paint Code
Color
Crystal Silver Metallic
Nighthawk Black Pearl
Monterey Blue Pearl*1
Vermont Green Pearl
Premium White Pearl
Ruby Red Pearl*1
Naples Gold Metallic
B-91M
B-92P
B-93P
G-97P
NH-624P
R-504P
YR-524MProCarManuals.com
Page 284 of 1954
Chassis and Paint Codes
2000 Model
Vehicle Identification Number
U.S. model: 000001~
Canada model: 800001 ~
Transmission Number
Engine Number
Vehicle Identification Number
and Federal Motor Vehicle
Safety Standard Certification.
Vehicle Identification Number
and Canadian Motor Vehicle
Safety Standard Certification.
COLOR LABEL
INT. COLOR
TYPE F
EXT. COLOR
G-97P
KA SZ3 A6 C
Paint Code
Paint Code
Paint Code
Color
B-92P
B-93P
G-97P
NH-552M
R-504P
YR-524M
Nighthawk Black Pearl
Monterey Blue Pearl
Vermont Green Pearl*1
Sebring Silver Metallic
Ruby Red Pearl* 1
Naples Gold Metallic
*1: U.S. model onlyProCarManuals.com
Page 285 of 1954
Chassis and Paint Codes
2001 Model
Vehicle Identification Number
Transmission Number
*1: U.S. model only
Engine Number
Vehicle Identification Number
and Federal Motor Vehicle
Safety Standard Certification.
Vehicle Identification Number
and Canadian Motor Vehicle
Safety Standard Certification.
COLOR LABEL
INT. COLOR
TYPE F
EXT. COLOR
G-97P
KA SZ3 A6 C
Paint Code
B-92P
B-502P
G-97P
NH-623M
NH-624P
R-507P
YR-524M
Nighthawk Black Pearl
Indigo Blue Pearl*1
Vermont Green Pearl* 1
Satin Silver Metallic
Premium White Pearl
Firepepper Pearl
Naples Gold Metallic
Color
Paint Code
Paint CodeProCarManuals.com