relay ACURA TL 1995 Service Repair Manual
[x] Cancel search | Manufacturer: ACURA, Model Year: 1995, Model line: TL, Model: ACURA TL 1995Pages: 1771, PDF Size: 62.49 MB
Page 45 of 1771
13. Remove the battery cables from the under hood fuse/
relay box, then remove the under-hood fuse/relay box.
14. Remove the engine wire harness connector.
BATTERY
CABLES
CONNECTOR
6 x 1.0 mm
12 N-m (1.2 kgf-m,
8.7 Ibf-ft)
UNDER-HOOD
FUSE/RELAY
BOX
6 x 1.0 mm
12 N-m (1.2 kgf-m,
8.7 Ibf-ft)
15. Raise the power steering (P/S) fluid reservoir, then
remove the vacuum hoses, vacuum tube and vacuum
tank.
NOTE: Do not disconnect the P/S hoses.
6 x 1.0 mm
12 N-m (1.2 kgf-m, 8.7 Ibf-ft)
VACUUM
TANK
VACUUM
HOSES
VACUUM
TUBE
16. Disconnect the ignition control module (ICM) con-
nector, and remove the engine ground cable.
GROUND CABLE
6 x 1.0 mm
12 N-m (1.2 kgf-m, 8.7 Ibf-ft)
6 x 1.0 mm
12 N-m (1.2 kgf-m,
8.7 Ibf-ft)
ICM CONNECTOR
17. Disconnect the engine wire harness connector on
the right side of the engine compartment.
18. Remove the ground cable and wire harness clamp.
6 x 1.0 mm
12 N-m (1.2 kgf-m,
8.7 Ibf-ft)
GROUND
CABLE
6 x 1.0 mm
12 N-m (1.2 kgf-m,
8.7 Ibf-ft)
ENGINE WIRE
HARNESS CONNECTORProCarManuals.com
Page 73 of 1771
Cylinder Head s
Remova l
Engine remova l i s no t require d fo r thi s procedure .
Mak e sur e jack s an d safet y stand s ar e
place d properl y an d hois t bracket s ar e attache d th e t o
correc t position s o n th e engine .
CAUTION :
Us e fende r cover s t o avoi d damagin g painte d sur -
faces .
Unplu g th e wirin g connector s carefull y whil e holdin g
th e connecto r portio n to avoi d damage .
T o avoi d damagin g th e cylinde r head , wai t unti l th e
engin e coolan t temperatur e drop s belo w 100° F (38°C )
befor e loosenin g th e retainin g bolts .
NOTE :
Mark al l wirin g an d hose s t o avoi d misconnection .
Also , b e sur e tha t the y d o no t contac t othe r wirin g o r
hoses , o r interfer e wit h othe r parts .
Inspec t th e timin g bel t befor e removin g th e cylinde r
head .
Tur n th e crankshaf t pulle y s o tha t th e No . 1 pisto n i s
a t to p dea d cente r (se e pag e 6-10 ).
1 . Mak e sur e yo u hav e th e anti-thef t cod e fo r th e
radio , the n writ e dow n th e frequencie s fo r th e
radio' s prese t buttons .
2 . Disconnec t th e batter y negativ e termina l first , the n
the positiv e terminal .
3. Drai n th e engin e coolan t (se e pag e 10-5 ).
4 . Remov e th e engin e cove r (se e pag e 5-3 ).
5 . Remov e th e intak e ai r duc t an d ai r cleane r housin g
assembl y (se e pag e 5-3 ).
6 . Remov e th e throttl e cove r (se e pag e 5-4 ).
7 . Remov e th e throttl e cabl e an d cruis e contro l cabl e
b y loosenin g th e locknuts , the n sli p th e cabl e end s
ou t o f th e accelerato r linkag e (se e pag e 5-4 ).
NOTE :
Take car e no t t o ben d a cabl e whe n removin g it .
Alway s replac e an y kinke d cabl e wit h a ne w one .
Adjus t th e throttl e cabl e whe n installin g (se e
sectio n 11 ).
Adjus t th e cruis e contro l cabl e whe n installin g
(se e sectio n 23 ). 8
. Remov e th e uppe r radiato r hos e an d wate r bypas s
hoses.
UPPER RADIATO RHOSE
WATE R BYPAS SHOSES
9. Remov e th e batter y an d batter y bas e (se e pag e 5-4 ).
10 . Remov e th e vacuu m hoses , the n remov e th e clam p
fro m th e under-hoo d fuse/rela y bo x (se e pag e 5-4 ).
11 . Remov e th e batter y cable s fro m th e under-hoo d
fuse/rela y box , the n remov e th e under-hoo d fuse /
rela y box .
12 . Remov e th e engin e wir e harnes s connector .
BATTERY CABLE S
CONNECTO R
6 x 1. 0 m m12 N- m (1. 2 kgf-m , 8. 7 Ibf-ft )
UNDER-HOO DFUSE/RELAYBOX
6 x 1. 0 m m12 N- m 11. 2 kgf-m ,8.7 Ibf-ft )
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Page 176 of 1771
System Descriptio n
System Connector s [Das h an d Floor ]
C427/C601
C61 3 C61
2DASHBOAR D
WIR E HARNES S
C482
C41 8
C41 7
REA RHARNES S
FUEL UNI TSUB-HARNES S
C773
C519/C77 1
MAIN WIR EHARNES SC429
REA R WIR EHARNES S
C603
C40 5
C41 5
UNDER-DAS HFUSE/RELAYBOX
C40 6
C40 4
C403
C40 2
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Page 181 of 1771
II. Powertrain Control Module (PCM) Reset Procedure
Either of the following actions will reset the PCM
Use the OBD II scan tool or Honda PGM Tester to clear the PCM's memory.
NOTE: See the OBD II scan tool or Honda PGM Tester user's manuals for specific operating instructions.
Turn the ignition switch OFF. Remove the BACK UP RADIO (10 A) fuse from the under-hood fuse/relay box for
10 seconds.
BACK UP RADIO
(10 A) FUSE
UNDER-HOOD
FUSE/RELAY
BOX
III. Final Procedure (this procedure must be done after any troubleshooting)
1. Remove the SCS Service Connector if it is connected.
NOTE: If the SCS service connector is connected and there are no DTCs stored in the PCM, the MIL will stay
on when the ignition switch is turned ON (II).
2. Do the PCM Reset Procedure.
3. Turn the ignition switch OFF.
4. Disconnect the OBD II scan tool or Honda PGM Tester from the Data Link Connector (16P).ProCarManuals.com
Page 200 of 1771
PGM-FI System
System Description (cont'd)
3. Fuel Cut-off Control
During deceleration with the throttle valve closed, current to the fuel injectors is cut off to improve fuel economy at
speeds over 1,000 rpm.
Fuel cut-off action also takes place when engine speed exceeds 6,500 rpm, regardless of the position of the throttle
valve, to protect the engine from over-revving.
4. A/C Compressor Clutch Relay .
When the PCM receives a demand for cooling from the air conditioning system, it delays the compressor from being
energized, and enriches the mixture to assure a smooth transition to the A/C mode.
5. Evaporative Emission (EVAP) Purge Control Solenoid Valve
'96 model: When the engine coolant temperature is below 158°F (70°C), the PCM controls the EVAP purge control
solenoid valve which cuts vacuum to the EVAP purge control canister diaphragm.
'97 - 98 models: When the engine coolant temperature is above 99°F (37°C), the PCM controls the EVAP purge control
solenoid valve which controls vacuum to the EVAP purge control canister.
6. Intake Air Bypass (IAB) Low Control Solenoid Valve, Intake Air Bypass (IAB) High Control Solenoid Valve
When engine speed is below 3,350 rpm, the IAB High Control Solenoid Valve and IAB Low Control Solenoid Valve are
activated by a signal from the PCM. Intake air flows through a long chamber path, increasing torque at low RPM.
When engine speed is 3,350 - 3,950 rpm, the IAB Low Control Solenoid Valve is deactivated by the PCM. Intake air
flows through a short chamber path, increasing mid-range torque.
When the engine rpm is above 3,950 rpm, the IAB Low Control Solenoid Valve and IAB High Control Solenoid Valve are
deactivated by the PCM. This creates a very short intake path and increases high-speed torque.
7. Exhaust Gas Recirculation (EGR) Control Solenoid Valve
When the EGR is required for control of oxides of nitrogen (NOx) emissions, the PCM controls the EGR control solenoid
valve which supplies regulated vacuum to the EGR valve.
ECM Fail-safe/Back-up Functions
1. Fail-safe Function
When an abnormality occurs in a signal from a sensor, the PCM ignores that signal and assumes a pre-programmed
value for that sensor that allows the engine to continue to run.
2. Back-up Function
When an abnormality occurs in the PCM itself, the fuel injectors are controlled by a back-up circuit independent of the
system in order to permit minimal driving.
3. Self-diagnosis Function [Malfunction Indicator Lamp (MIL)]
When an abnormality occurs in a signal from a sensor, the PCM supplies ground for the MIL and stores the DTC in
erasable memory. When the ignition is initially turned on, the PCM supplies ground for the MIL for two seconds to
check the MIL bulb condition.
4. Two Driving Cycle Detection Method
To prevent false indications, the two driving cycle detection method is used for the H02S, fuel metering-related, idle
control system, ECT sensor, EGR system, TWC, EVAP control system and other self-diagnostic functions. When an
abnormality occurs, the PCM stores it in its memory. When the same abnormality recurs after the ignition switch is
turned OFF and ON (II) again, the PCM informs the driver by lighting the MIL.
However, to ease troubleshooting, this function is cancelled when you short the service check connector. The MIL will
then blink immediately when an abnormality occurs.ProCarManuals.com
Page 201 of 1771
Powertrain Control Module (PCM)
NOTE: If this symptom is intermittent, check for a loose fuse No. 1 (BACK UP
LIGHTS, METER LIGHTS, 10 A) in the under-dash fuse/relay box, a poor con-
nection at PCM terminal A7, or an intermittent open in the GRN/RED wire
between the PCM (A7) and the gauge assembly.
Is the low oil pressure light on?
Try to start the engine.
Does the engine start?
Check for an open in the wire or
bulb (MIL line):
1. Turn the ignition switch OFF.
2. Connect the PCM connector ter-
minal A7 to body ground with a
jumper wire.
3. Turn the ignition switch ON (II).
Is the MIL on?
Substitute a known-good PCM,
and recheck. If symptom/indica-
tion goes away, replace the origi-
nal
PCM.
— Repair short or open in the
wire between NO. 1 (BACK-UP
LIGHTS, METER LIGHTS) (10
A) fuse and gauge assembly.
— Replace No. 1 (BACK-UP
LIGHTS, METER LIGHTS) (10 A)
fuse.
PCM CONNECTOR A (26P)
Check for an open in the wires
(PG1, PG2 lines):
1. Turn the ignition switch ON (II).
2. Measure voltage between
body ground and PCM con-
nector terminals A12 and A25
individually.
Wire side of female terminals
Is there less than 1.0 V?
Repair open in the wire(s)
between PCM and G101 (located
at intake manifold) that had
more than 1.0 V.
PCM CONNECTOR A (26P)
JUMPER WIRE
Wire side of female terminals
Repair open in the wires
between PCM (A7) and gauge
assembly.
Replace the MIL bulb.
Substitute a known-good PCM
and recheck. If symptom/indica-
tion goes away, replace the origi-
nal
PCM.
Turn the ignition switch ON (II).
The Malfunction Indicator Lamp
(MIL) never comes on (even for
two seconds) after ignition is
turned on (II).ProCarManuals.com
Page 203 of 1771
(From pag e 11-54 )
Chec k fo r a shor t i n th e wir e (MI L
line) :
1. Tur n th e ignitio n switc h OFF .2. Disconnec t th e PC M connec -tor A (26P) .3. Tur n th e ignitio n switc h O N (II) .
Is th e MI L ON ?Repai r shor t t o bod y groun d i n
th e wir e betwee n th e PC M (A7 )
and MIL .
Substitut e a known-goo d PC Mand recheck . I f symptom/indica -
tio n goe s away , replac e th e origi -
nal PCM .
(From pag e 11-54 )
I s th e fus e OK ?
Inspec t IG 1 I G COI L (3 0 A ) fus e in
th e ignitio n coi l fus e holde r box . Repai
r shor t i n th e wir e
betwee n EC U (PCM ) (2 0 A )
fus e an d PGM-F I mai n relay .
Replac e EC U (PCM ) (2 0 A )
fuse .
Is th e fus e OK ? Repai
r shor t i n th e wir e
betwee n IG 1 I G COI L (3 0 A )
fus e an d PGM-F I mai n relay .
Replac e IG 1 I G COI L (3 0 A )
Chec k fo r a shor t i n a sensor :
1. Tur n th e ignitio n switc h O N (II) .2. Disconnec t th e 3 P connecto r
o f eac h senso r on e a t time :
MA P senso r
T P senso r
EG R valv e lif t senso r
TC S contro l valv e angl e sen -
sorFue l tan k pressur e senso r('97-98 models )
Does th e MI L g o OF F momen -
tarily ? Replac
e th e senso r tha t cause dthe ligh t t o g o out .
(To pag e 11-56 )
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Page 204 of 1771
PGM-FI Syste m
Powertrai n Contro l Modul e (PCM ) (cont'd )
(From pag e 11-55 )
Chec k fo r a shor t i n th e wire s
(VC C lines) :
1 . Tur n th e ignitio n switc h OFF .
2 . Disconnec t th e PC M connec -
tor D (22P) .3. Chec k fo r continuit y betwee nbody groun d an d PC M con -necto r terminal s D1 0 an d D2 1individually .
Is ther e continuity ?
I s ther e batter y voltage ?
Chec k fo r a n ope n i n th e wire s
(L G lines) :
1 . Reconnec t al l senso r connec -
tors .
2 . Reconnec t th e PC M connecto r
D (22P) .3. Tur n th e ignitio n switc h O N (II) .
4 . Measur e voltag e betwee n
bod y groun d an d PC M connec -
to r terminal s A2 6 an d B 9 indi -
vidually .
I s ther e les s tha n 1. 0 V ?
Substitut e a known-goo d PC M
an d recheck . I f symptom/indica -
tio n goe s away , replac e th e origi -
nal PCM .
PCM CONNECTO R D (22P )
Repai r shor t t o bod y groun d
i n th e wir e betwee n PC M
(D10 ) an d MA P sensor .Repair shor t t o bod y groun d in
th e wir e betwee n PC M (D21 )
an d EG R valv e lif t sensor , T P
sensor , TC S contro l valv e
angl e senso r o r fue l tan k pres -
sur e senso r ('9 7 - 9 8 models) .Wir
e sid e o f femal e terminal s
A (26P)
PCM CONNECTOR S
Repair ope n i n th e wire(s )
betwee n PC M (A13 , B1 ) an d
PGM-F I mai n relay .
Chec k fo r poo r connection s
o r loos e wire s a t th e PGM-F I
mai n relay .
Tes t th e PGM-F I mai n rela y
(se e pag e 11-129 ). Wir
e sid e o f femal e terminal s
PCM CONNECTOR S
A (26P)B (16P)
Repai r ope n i n th e wire(s )
betwee n PC M (A26 , B9 ) an d
G10 1 tha t ha d mor e tha n 1. 0 V .Wir e sid e o f femal e terminal s
Check fo r a n ope n i n th e wire s
(IG P lines) :
1 . Tur n th e ignitio n switc h O N (II) .
2 . Measur e voltag e betwee n bod y
groun d an d PC M connecto r
terminal s A1 3 an d B 1 individu -
ally .B (16P )
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Page 205 of 1771
Idle Control System
System Description
The idle speed of the engine is controlled by the Idle Air Control (IAC) Valve.
The valve changes the amount of air bypassing into the intake manifold in response to electric current controlled by the
PCM. When the IAC Valve is activated, the valve opens to maintain the proper idle speed.
ENGINE
COOLANT
IAC VALVE
INTAKE
MANIFOLD
PCM
From
PGM-FI
MAIN
RELAY
FAST
IDLE
THERMO
VALVE
IDLE
ADJUSTING
SCREW
VARIOUS
SENSORS
ENGINE
COOLANTProCarManuals.com
Page 208 of 1771
(From pag e 11-104 )
I s ther e a clickin g nois e fro m
th e A/ C compresso r clutch ?
Chec k fo r th e operatio n o f th e
A/C :1. Star t th e engine .
2 . Tur n th e blowe r switc h ON .
3 . Tur n th e A/ C switc h ON .
Doe s th e A/ C operate ?
Ai r conditionin g signa l i s OK . Chec
k fo r a n ope n i n th e wir e
(ACC line) :Momentaril y connec t th e A/ C
clutc h rela y 4 P connecto r termi -
nal No . 2 to bod y groun d wit h ajumpe r wir e severa l times . A/
C CLUTC H RELA Y CONNECTO R (C308 )
JUMPE RWIRE
Wire sid e o f
femal e terminal s
I s ther e a clickin g nois e fro m
th e A/ C compresso r clutch ? Se
e ai r conditione r inspectio n
(se e sectio n 22 ).
Repai r ope n in th e wir e betwee n
th e PC M (A8 ) an d th e A/ C clutc h
relay.
PCM CONNECTOR S
A (26P)
Chec k fo r a n ope n i n th e wir e
(AC S line) :
Measur e voltag e betwee n PC M
connecto r terminal s A2 6 an d C2 . Wir
e sid e o f femal e terminal s
I s voltag e les s tha n 1. 0 V ? Repai
r ope n i n th e wir e betwee n
th e PC M (C2 ) an d th e A/ C pres -
sur e switc h A or radiato r fa n
diode .
Substitut e a known-goo d PC M
an d recheck . I f symptom/indi -
catio n goe s away , replac e th e
origina l PCM .
Se e th e ai r conditione r inspec -
tio n (se e sectio n 22 ).
C (12P )
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