Test ACURA TL 1995 Service User Guide

Powertrain Contro l Modul e Dat a
B y connectin g th e OB D II sca n too l o r th e Hond a PG M Teste r t o th e 16 P dat a lin k connecto r (DLC) , variou s dat a ca n b e
retrieve d fro m th e PCM . Th e item s liste d in th e tabl e belo w confor m to th e SA E recommende d practice .
Th e Hond a PG M Teste r als o read s dat a beyon d tha t recommende d b y SAE .
Understandin g thi s dat a wil l hel p t o fin d th e cause s o f intermitten t failure s o r engin e problems .
NOTE:
The "operatin g values " give n belo w ar e approximat e value s an d ma y b e differen t dependin g o n th e environmen t an d
the individua l car .
Unles s note d otherwise , "a t idl e speed " mean s idlin g wit h th e engine completel y warme d up , transmissio n i n o r
position , an d th e A/ C an d al l accessorie s turne d off .
Dat aDescriptio nOperating Valu e
Freeze Dat a
Diagnosti c
Troubl e Cod e
(DTC )
If th e PC M detect s a problem , i t wil l stor e it a s a cod e
consistin g o f on e lette r an d fou r numbers .
Dependin g o n th e problem , a n SAE-define d cod e
(P0xxx ) o r a Honda-define d cod e (P1xxx ) wil l b e outpu t
t o th e tester . I
f n o proble m is detected ,
ther e i s n o output .
Engin e Spee d Th
e PC M compute s engin e spee d fro m th e signal s sen t
fro m th e Crankshaf t Positio n sensor .
Thi s dat a is use d fo r determinin g th e tim e an d amoun t
o f fue l injection . Nearl
y th e sam e a s
tachomete r indicatio n a t
idl e speed :
640 5 0 rp m
Vehicl e Spee d Th
e PC M convert s puls e signal s fro m th e Vehicl e
Spee d Senso r (VSS ) int o spee d data . Nearl
y th e sam e a s
speedomete r indicatio n
Manifol d
Absolut e
Pressur e (MAP )
The absolut e pressur e create d in th e intak e manifol d b y
engin e loa d an d speed . Wit
h engin e stopped :
Nearl y th e sam e a s atmo -
spheri c pressur e a t idl e
speed :
24-37 kP a (180-28 0
mmHg, 7.1-11. 0 inHg )
Engin e Coolan t
Temperatur e
(ECT)
The EC T senso r convert s coolan t temperatur e int o
voltag e an d signal s th e PCM . Th e senso r i s a thermisto r
whos e interna l resistanc e change s wit h coolan t
temperature . Th e PC M use s th e voltag e signal s fro m
th e EC T senso r t o determin e th e amoun t o f injecte d
fuel . Wit
h col d engine :
Sam e a s ambien t temper -
atur e an d IA T
Wit h engin e warme d up :
approx . 158-212° F
(70-100°C )
Heate d Oxyge n
Senso r (H02S )
(Bank 1, Sensor 1)
(Ban k 2 , Senso r 1 )
(Senso r 2 )
Th e Heate d Oxyge n Senso r detect s th e oxyge n conten t
i n th e exhaus t ga s an d send s voltag e signal s to th e
PCM . Base d o n thes e signals , th e PC M control s th e
air/fue l ratio . Whe n th e oxyge n conten t i s hig h (tha t is ,
whe n th e rati o is leane r tha n th e stoichiometri c ratio) ,
th e voltag e signa l i s lower . Whe n th e oxyge n conten t i s
lo w (tha t is , whe n th e rati o is riche r tha n th e stoichio -
metric ratio) , th e voltag e signa l i s higher .
0.0-1.2 5 V
A t idl e speed :
about 0.1-0. 9 V
O
(Senso r 1 )
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Troubleshooting

How to Read Flowcharts

A flowchart is designed to be used from start to final repair. It's like a map showing you the shortest distance. But beware:

if you go off the "map" anywhere but a "stop" symbol, you can easily get lost.

Describes the conditions or situation to start a troubleshooting flowchart.

Asks you to do something; perform a test, set up a condition etc.

Asks you about the result of an action, then sends you in the appropriate troubleshooting direction.

The end of a series of actions and decisions, describes a final repair action and sometimes directs you to

an earlier part of the flowchart to confirm your repair.

NOTE:

The term "Intermittent Failure" is used in these charts. It simply means a system may have had a failure, but it checks

out OK at this time. If the Malfunction Indicator Lamp (MIL) on the dash does not come on, check for poor connections

or loose wires at all connectors related to the circuit that you are troubleshooting (see illustration below).

Most of the troubleshooting flowcharts have you reset the Powertrain Control Module (PCM) and try to duplicate the

Diagnostic Trouble Code (DTC). If the problem is intermittent and you can't duplicate the code, do not continue through

the flowchart. To do so will only result in confusion and, possibly, a needlessly replaced PCM.

"Open" and "Short" are common electrical terms. An open is a break in a wire or at a connection. A short is an acci-

dental connection of a wire to ground or to another wire. In simple electronics, this usually means something won't

work at all. In complex electronics (like PCM's), this can sometimes mean something works, but not the way it's sup-

posed to.

TIGHT

LOOSE
(bold type)
STOP
DECISION
ACTION
(bold type)
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PGM-FI Syste m
Powertrai n Contro l Modul e (PCM ) (cont'd )
The Malfunctio n Indicato r Lam p
(MIL ) stay s o n o r come s o n afte r
tw o seconds .
Chec k th e Diagnosti c Troubl e
Code (DTC) :1. Connec t a sca n too l o r Hond a
PG M Tester .
2 . Tur n th e ignitio n switc h O N (II) .
3 . Rea d th e DT C wit h th e sca n
too l o r Hond a PG M Tester .
Are an y DTC(s ) indicated ?
Check th e DT C b y MI L indication :
1 . Tur n th e ignitio n switc h OFF .
2 . Connec t th e SC S servic e con -
necto r t o th e servic e chec k
connector .
3 . Tur n th e ignitio n switc h O N (II) .
Doe s th e MI L indicat e an y DTC ?
Tr y t o star t th e engine .
Doe s th e engin e start ?
NOTE :When ther e is n o Diagnosti c Troubl e Cod e (DTC ) stored , th e MI L wil l sta y o n if th e SC S servic e
connecto r i s connecte d an d th e ignitio n switc h is on .
I f thi s sympto m is intermittent , chec k for :
— A loos e EC U (PCM ) (2 0 A ) fus e in th e under-hoo d fuse/rela y bo x
— A loos e No . 2 FUE L PUM P (1 0 A ) fus e in th e under-das h fuse/rela y bo x
— A n intermitten t shor t i n th e wire betwee n th e PC M (C5 ) an d th e servic e chec k connecto r
— A n intermitten t shor t i n th e wire betwee n th e PC M (A7 ) an d th e gaug e assembl y
— A n intermitten t shor t i n th e wir e betwee n th e PC M (D10 ) an d th e MA P senso r
— A n intermitten t shor t i n th e wire betwee n th e PC M (D21 ) an d th e T P sensor , EG R valv e lif t
sensor , TC S contro l valv e angl e sensor , Fue l tan k pressur e sensor *
Se e th e OB D II sca n too l o r Hond a PG M Teste r user' s manual s fo r specifi c operatin g instruc -
tions.: '9 7 - 9 8 model s
G o to troubleshootin g procedures .
(se e pag e 11-32 )
Repai r ope n o r shor t i n wir e
betwee n the PCM (D4 ) an d
Dat a Lin k Connector .
G o to troubleshootin g proce -
dures . (se e pag e 11-32 )
PCM CONNECTO R C (12P )
Chec k fo r a shor t i n th e wir e (SC S
line) :
1 . Sto p th e engin e an d tur n th e
ignitio n switc h O N (II) .2. Measur e voltag e betwee n th e
PC M connecto r termina l C 5
an d bod y ground . (T
o pag e 11-55 )
Wire sid e o f femal e terminal s
I s ther e approx . 5 V ?
(T o pag e 11-55 ) Repai
r shor t t o bod y groun d in
th e wir e betwee n PC M (C5 ) an d
servic e chec k connector .
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Fast Idl e Therm o Valv e
Descriptio n
T o preven t errati c runnin g whe n th e engin e i s warmin g
up , i t i s necessar y t o rais e th e idl e speed . Th e fas t idl e
therm o valv e i s controlle d b y a thermowa x plunger .
Whe n th e engin e i s cold , th e engin e coolan t surround -
in g th e thermowa x contract s th e plunger , allowin g addi -
tiona l ai r t o b e bypasse d int o th e intak e manifol d s o tha t
th e engin e idle s faster . Whe n th e engin e reache s operat -
in g temperature , th e valv e closes , reducin g th e amoun t
o f ai r bypassin g int o th e intak e manifold .
FASTIDLETHERM OVALVE
IDLEADJUSTIN GSCREW
IACVALV E
AIR BYPAS SVALVE
WAX
Inspectio n
NOTE: Th e fas t idl e therm o valv e i s factor y adjusted ; i t
shoul d no t b e disassembled .
1 . Remov e th e cove r o f th e fas t idl e therm o valve .
2 . Star t th e engine .
3.Pu t you r finge r o n th e valv e sea t are a an d mak e sur e
tha t ther e i s ai r flo w wit h th e engin e col d (engin e
coolan t temperatur e belo w 86°F , 30°C ) an d idling .
FASTIDLETHERM OVALVE
• I f not , replac e th e fas t idl e therm o valv e an d retest .
O-RING SReplace .
12 N- m(1.2 kgf-m , 8. 7 Ibf-ft )
4.
5.
Star t th e engine . Hol d th e engin e a t 3,00 0 rp m wit h n o
loa d (transmissio n in o r position ) unti l th e radia -
to r fa n come s on , the n le t i t idle .
Chec k tha t th e valv e i s completel y closed . I f not , ai r
suctio n ca n b e fel t i n th e valv e sea t area .
I f an y suctio n is felt , th e valv e is leaking .
Chec k engin e coolan t leve l an d fo r ai r i n th e engin e
coolin g syste m (se e sectio n 10 ).
I f OK , replac e th e fas t idl e therm o valv e an d
recheck .
NOTE: I f th e cove r o f fast idle therm o valv e wa s removed ,
d o th e PC M rese t procedure .
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Fuel Suppl y Syste m
Fuel Pressur e Regulato r
Descriptio n
Th e fue l pressur e regulato r maintain s a constan t fue l pres -
sur e to th e fue l injectors . Whe n th e differenc e betwee n th e
fue l pressur e an d manifol d pressur e exceed s 25 0 kP a
(2.5 5 kgf/cm
2, 36. 3 psi) , th e diaphrag m is pushe d
upward , an d th e exces s fue l i s fe d bac k int o th e fue l tan k
throug h th e retur n line .
CLOSED :
INTAKE MANIFOL DVACUUM
DIAPHRAG M
FUELINLE T
OPEN :INTAK E MANIFOL DVACUUM
FUEL RETUR N DIAPHRAG
M
FUE L
INLE T
Testin g
Do no t smok e durin g th e test . Kee p ope n
flame s awa y fro m you r wor k area .
1 . Attac h th e specia l too l t o th e servic e por t o n th e fue l
rai l ('9 7 - 9 8 models : fue l filter ) (se e pag e 11-120 ).
2 . Star t th e engine .
Pressur e shoul d be :
26 0 - 31 0 kP a (2.6 5 - 3.1 5 kgf/cm
2, 3 8 - 4 5 psi )
(wit h th e fue l pressur e regulato r vacuu m hos e dis -
connecte d an d pinched )
'9 6 model :
FUELPRESSUR EGAUGE07406 - 0040001
CLAMP FUE
LPRESSUR EREGULATO R
'97 - 9 8 models :
FUELPRESSUR EREGULATO R FUE
L
PRESSUR E
GAUG E
07406 - 004000 1
FUELFILTE R
3. Reconnec t th e vacuu m hos e t o th e fue l pressur e
regulator .
4 . Chec k tha t th e fue l pressur e rise s whe n th e vacuu m
hos e fro m th e fue l pressur e regulato r i s disconnecte d
again . I f th e fue l pressur e di d no t rise , replac e th e
fue l pressur e regulator .
CLAMP
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Fuel Suppl y Syste m
Fuel Pum p
Testin g
Do no t smok e durin g th e test . Kee p ope n
flam e awa y fro m you r wor k area .
I f yo u suspec t a proble m wit h th e fue l pump , chec k tha t
th e fue l pum p actuall y runs ; whe n it i s ON , yo u wil l hea r
som e nois e i f yo u hol d you r ea r t o th e fue l fil l por t wit h
th e fue l fil l ca p removed . Th e fue l pum p shoul d ru n fo r
tw o second s whe n ignitio n switc h i s firs t turne d on . I f
th e fue l pum p doe s no t mak e noise , chec k a s follows :
1 . Remov e th e trun k floor .
2 . Disconnec t th e 3 P connector .
CAUTION : B e sur e t o tur n th e ignitio n switc h OF F
befor e disconnectin g th e wires .
3 . Disconnec t th e PGM-F I mai n rela y connecto r an d
connec t th e No . 2 termina l an d No . 5 terminal * wit h
a jumpe r wire . * : 8 P connecto r
4.
PGM-F I MAI N RELA Y CONNECTOR S
8P (C417 )
JUMPE R WIR E
Wire sid e o f femal e terminal s
Check tha t batter y voltag e i s availabl e betwee n th e
fue l uni t sub-harnes s connecto r termina l No . 3 an d
bod y groun d whe n th e ignitio n switc h is turne d O N (II) .
FUE L UNI T SUB-HARNES SCONNECTOR (C519 )
Termina l sid e o f mal e terminal s
If batter y voltag e is available , chec k th e fue l pum p
ground . I f th e groun d i s OK , replac e th e fue l
pump .
I f ther e is n o voltage , chec k th e wir e harnes s (se e
pag e 11-130 ).
4 P (C418 )
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PGM-FI Main Relay

Description

This PGM-FI main relay is located at the left side of the

cowl. The PGM-FI main relay actually contains two indi-

vidual relays. One relay is energized whenever the igni-

tion is on. It supplies battery voltage to the PCM, power

to the fuel injectors, and power for the second relay. The

second relay is energized for two seconds when the

ignition is switched on, and when the engine is running.

It supplies power to the fuel pump.

PGM-FI

MAIN RELAY

FUEL PUMP
Relay Testing

NOTE: If the car starts and continues to run, the PGM-FI

main relay is OK.

Remove the PGM-FI main relay.

Attach the battery positive terminal to the No. 3*

terminal and the battery negative terminal to the

No. 2* terminal of the PGM-FI main relay. Then

check for continuity between the No. 5* terminal and

No. 2 terminal of the PGM-FI main relay.

If there is continuity, go on to step 3.

If there is no continuity, replace the relay and

retest.

No. 4
*: 8P CONNECTOR

3. Attach the battery positive terminal to the No. 4 ter-

minal and the battery negative terminal to the No.

7* terminal of the PGM-FI main relay. Then check

that there is continuity between the No. 3 terminal

and No. 1 terminal of the PGM-FI main relay.

• If there is continuity, go on to step 4,

• If there is no continuity, replace the relay and

retest.

4. Attach the battery positive terminal to the No. 1 ter-

minal and battery negative terminal to the No. 2*

terminal of the PGM-FI main relay. Then check that

there is continuity between the No. 5* terminal and

No. 2 terminal of the PGM-FI main relay.

If there is continuity, the relay is OK;

If the fuel pump still does not work, go to

Harness Testing on the next page.

If there is no continuity, replace the relay and

retest.ProCarManuals.com

Testing
Intake Ai r Bypas s (IAB ) Lo w Contro l Valv e
1 . Disconnec t th e No . 2 vacuu m hos e fro m th e vacu -
u m hos e manifold , an d attac h a vacuu m pum p to th e
vacuu m hos e manifold .
IAB LO WCONTRO L SOLENOI D VALV E
No. 2 VACUUM HOSE
2.
VACUU M PUMP /GAUG EA973X - 04 1 - XXXX X
Apply vacuu m an d verif y tha t th e IA B contro l dia -
phrag m valv e hold s vacuu m an d tha t a s th e vacuu m
i s applie d an d release d th e IA B contro l diaphrag m
valv e ro d move s i n an d out .
I f th e IA B contro l diaphrag m valv e doe s no t hol d
vacuu m o r th e IA B contro l diaphrag m valv e ro d
doe s no t mov e i n an d out , replac e th e IA B con -
tro l valv e an d retest . Intak
e Ai r Bypas s (IAB ) Hig h Contro l Valv e
1.Disconnec t th e No . 8 vacuu m hos e fro m th e vacu -
u m hos e manifold , an d attac h a vacuu m pum p t o
th e vacuu m hos e manifold .
IAB HIG H
CONTRO L SOLENOI D VALV E
No. 8 VACUU M HOS E
2.Appl y vacuu m an d verif y tha t th e IA B contro l
diaphrag m valv e hold s vacuu m an d tha t a s th e vac -
uu m is applie d an d release d th e IA B contro l dia -
phrag m valv e ro d move s in an d out .
I f th e IA B contro l diaphrag m valv e doe s no t hol d
vacuu m o r th e IA B contro l diaphrag m valv e ro d
doe s no t mov e i n an d out , replac e th e IA B con -
tro l valv e an d retest .
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Troubleshooting Procedure s
Checking th e Diagnosti c Troubl e Cod e (DTC )
wit h a n OB D II Sca n too l o r Hond a PG M Teste r
When th e PC M sense s a n abnormalit y i n th e inpu t o r outpu t systems , th e indicato r ligh t i n th e gaug e assembl y wil l
blink . Whe n th e 16 P Dat a Lin k Connecto r (DLC ) (locate d behin d th e ashtray ) i s connecte d to th e OB D II Sca n Too l o r Hond a
PG M Teste r a s shown , th e sca n too l o r teste r wil l indicat e th e Diagnosti c Troubl e Cod e (DTC ) whe n th e ignitio n switc h i s
turne d O N (II) .
Whe n th e indicato r ligh t ha s bee n reporte d on , connec t th e OB D II Sca n Too l conformin g t o SA E J197 8 o r Hond a PG M
Teste r t o th e DL C (16P ) behin d th e ashtray . Tur n th e ignitio n switc h o n (II) , an d observ e th e DT C o n th e scree n o f th e OB D II
Sca n Too l o r Hond a PG M Tester . Afte r determinin g th e DTC , refe r t o th e electrica l syste m Symptom-to-Componen t Char t
o n pag e 14-6 8 an d 14-69 .
NOTE : Se e th e OB D II Sca n Too l o r Hond a PG M Teste r user' s manua l fo r specifi c instructions .
DATA LIN K CONNECTO R (16P )
OBD II SCA N TOO L o r
HOND A PG M TESTE R
Some PGM-F I problem s wil l als o mak e th e indicator light com e on . Afte r repairin g th e PGM-F I system , disconnec t th e
BAC K UP , RADI O fus e (1 0 A ) i n th e under-hoo d fuse/rela y bo x fo r mor e tha n 1 0 second s t o rese t th e PC M memory , the n
retest .
NOTE : Disconnectin g th e BAC K UP , RADI O fus e als o cancel s th e radi o anti-thef t code , prese t station s an d th e cloc k setting .
Ge t th e customer' s cod e number , an d mak e not e o f th e radi o preset s befor e removin g th e fus e s o yo u ca n rese t them .
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Checking th e Diagnosti c Troubl e Cod e (DTC )
wit h th e Servic e Chec k Connecto r an d Specia l Too l
Whe n th e PC M sense s a n abnormalit y i n th e inpu t o r outpu t systems , th e indicato r ligh t i n th e gaug e assembl y wil l blink .
Whe n th e Servic e Chec k Connecto r (locate d unde r th e das h o n th e passenge r side ) i s connecte d wit h th e specia l too l a s
shown , th e indicato r ligh t wil l blin k th e Diagnosti c Troubl e Cod e (DTC ) whe n th e ignitio n switc h i s turne d o n (II) .
Whe n th e indicato r ligh t ha s bee n reporte d on , connec t th e Servic e Chec k Connecto r wit h th e specia l tool .
Then tur n th e ignitio n switc h o n (II ) an d observ e th e indicato r light .
GAUG E ASSEMBL Y
SERVICE CHEC K
CONNECTO R (2P )
INDICATO R
LIGH T
SCS SERVIC E CONNECTO R07PAZ-001010 0
Codes 1 throug h 9 ar e indicate d b y individua l shor t blinks . Code s 1 0 an d abov e ar e indicate d b y a serie s o f lon g an d shor t
blinks . On e lon g blin k equal s 1 0 shor t blinks . Ad d th e lon g an d shor t blink s togethe r t o determin e th e code . Afte r deter -
mining th e code , refe r to th e electrica l syste m Symptom-t o Component Char t o n page s 14-6 8 an d 14-69 .
Some PGM-F I problem s wil l als o mak e th e indicato r ligh t com e on . Afte r repairin g th e PGM-F I system, disconnec t th e
BAC K UP , RADI O fus e (1 0 A ) i n th e under-hoo d fuse/rela y bo x fo r mor e tha n 1 0 second s t o rese t th e PC M memory , the n
retest .
NOTE : Disconnectin g th e BAC K UP , RADI O fus e als o cancel s th e radi o anti-thef t code , prese t station s an d th e cloc k setting .
Ge t th e customer' s cod e number , an d mak e not e o f th e radi o preset s befor e removin g th e fus e s o yo u ca n rese t them .
(cont'd )
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