1995 ACURA TL light

Intake Ai r Syste m Emissio
n Contro l Syste m
Intake Ai r Bypas s (IAB ) Contro l
Syste m (cont'd )
Intake Ai r Bypas s (IAB ) Contro l Valv e Testin g
1. Chec k th e IA B contro l valv e shaf t fo r bindin g o r stick -
ing.
2. Chec k th e IA B contro l valv e fo r smoot h movement .
3. Chec k tha t o f th e IA B contro l valv e is i n clos e con -
tac t wit h th e stoppe r whe n th e vacuu m hos e i s dis -
connecte d fro m th e IA B contro l diaphragm .
IAB CONTRO L VALV ESTOPPE R
4.Chec k tha t o f th e IA B contro l valv e is in clos e con -
tac t wit h th e full-clos e scre w whe n yo u appl y 5 1 kP a
(38 0 mmHg , 1 5 inHg ) o f vacuu m to th e IA B contro l
diaphragm .
FULL-CLOS ESCREW(Do no t adjust. )
If an y faul t i s found , clea n th e linkag e an d shaft s wit h
carbureto r cleaner . I f th e proble m stil l exist s afte r clean -
ing , disassembl e th e intak e manifol d an d chec k th e IA B
valv e bod y assembl y (se e sectio n 9 ).
Syste m Descriptio n
The emissio n contro l syste m include s a War m U p Thre e
Wa y Catalyti c Converte r (W U TWC) , a Thre e Wa y Catalyti c
Converte r (TWC) , Exhaus t Ga s Recirculatio n (EGR ) system ,
Positiv e Crankcas e Ventilatio n (PCV ) syste m an d
Evaporativ e Emissio n (EVAP ) Contro l system . Th e emis -
sio n contro l syste m is designe d t o mee t federa l an d stat e
emissio n standards .
Tailpipe Emissio n
Inspectio n
Do no t smok e durin g thi s procedure . Kee p
an y ope n flam e awa y fro m you r wor k area .
1 . Star t th e engine . Hol d th e engin e a t 3,00 0 rp m wit h
no loa d (transmissio n i n o r position ) unti l th e
radiato r fa n come s on , the n le t i t idle .
2 . Connec t a tachometer .
3 . Chec k an d adjus t th e idl e speed , i f necessar y (se e
pag e 11-117 ).
4 . War m u p an d calibrat e th e C O mete r accordin g to th e
mete r manufacturer' s instructions .
5 . Chec k idl e C O wit h th e headlights , heate r blower ,
rea r windo w defogger , coolin g fan , an d ai r condition -
er off .
NOTE : (Canada ) Pul l th e parkin g brak e leve r up .
Star t th e engine , the n chec k tha t th e headlight s ar e
off.
CO mete r shoul d indicat e 0.1 % maximum .
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Positive Crankcase Ventilation (PCV) System

Description

The Positive Crankcase Ventilation (PCV) system is

designed to prevent blow-by gas from escaping to the

atmosphere. The PCV valve contains a spring-loaded

plunger. When the engine starts, the plunger in the PCV

valve is lifted in proportion to intake manifold vacuum and

the blow-by gas is drawn directly into the intake manifold.

BREATHER

HOSE

PCV VALVE
BLOW-BY VAPOR

FRESH AIR
Inspection

1. Check the PCV hoses and connections for leaks and

clogging.

PCV HOSE

PCV VALVE

2.
BREATHER

PIPE

At idle, make sure there is a clicking sound from the

PCV valve when the hose between PCV valve and

intake manifold in lightly pinched with your fingers

or pliers.

Gently pinch here

If there is no clicking sound, check the PCV valve

grommet for cracks or damage. If the grommet is

OK, replace the PCV valve and recheck.
INTAKE

MANIFOLDProCarManuals.com

Description

The electronic control system consists of the Transmission Control Module (TCM), sensors, a linear solenoid, and four

solenoid valves.

Shift and lock-up are electronically controlled for comfortable driving under all conditions.

The TCM is located below the dashboard, behind the glove box on the passenger's side.

TCM

Linear Solenoid

Shift Control

Solenoid Valve A

Shift Control

Solenoid Valve B

Lock-up Control

Solenoid Valve A

Lock-up Control

Solenoid Valve B

Engine Speed Signal

Brake Switch Signal

Mainshaft Speed Sensor

Signal

Countershaft Speed

Sensor Signal

Vehicle Speed Sensor

Signal

Indicator Light

Self-Diagnosis Signal
Electronic Control System

Shift Control

Lock-up Control
Throttle Position

Sensor Signal

Engine Coolant

Temperature

Sensor Signal

Service Check

Connector

Barometric

Pressure Sensor

INTERLOCK

CONTROL UNIT

Self-Diagnosis

FunctionProCarManuals.com

Description

The parking brake mechanism locks the transmission by engaging the parking brake pawl into the parking gear which is

splined to the countershaft.

Shifting to position causes the parking brake pawl roller (installed at the end of the parking brake shift arm) to press the

parking brake pawl onto the parking gear. Even if the end of the parking brake pawl rides on top of the parking gear teeth,

slight movement of the countershaft will cause the parking brake pawl and the parking gear to mesh with each other com-

pletely, because the parking brake shift arm receives tension from the parking brake shift arm spring. The parking brake

pawl receives the tension (which acts to separate the parking brake pawl from the parking gear) from the parking pawl

spring.

PARKING GEAR
COUNTERSHAFT

1ST GEAR

PARKING BRAKE

PAWL

PARKING BRAKE

PAWL ROLLER

CONTROL SHAFT

PARKING PAWL

SPRING
PARKING BRAKE

SHIFT ARM
Parking Brake MechanismProCarManuals.com

Troubleshooting Procedures

Checking the Diagnostic Trouble Code (DTC)

with an OBD II Scan tool or Honda PGM Tester

When the TCM senses an abnormality in the input or output systems, the indicator light in the gauge assembly will

blink. When the 16P Data Link Connector (DLC) (located behind the ashtray) is connected to the OBD II Scan Tool or Honda

PGM Tester as shown, the scan tool or tester will indicate the Diagnostic Trouble Code (DTC) when the ignition switch is

turned ON(II).

When the indicator light has been reported on, connect the OBD II Scan Tool conforming to SAE J1978 or Honda PGM

Tester to the DLC (16P) behind the ashtray. Turn the ignition switch on (II), and observe the DTC on the screen of the OBD II

Scan Tool or Honda PGM Tester. After determining the DTC, refer to the electrical system Symptom-to-Component Chart

on page 14-56 and 14-57.

NOTE: See the OBD II Scan Tool or Honda PGM Tester user's manual for specific instruction.

OBD II SCAN TOOL or

HONDA PGM TESTER

Some PGM-FI problems will also make the indicator light come on. After repairing the PGM-FI system, disconnect the

BACK UP RADIO fuse (10 A) in the under-hood fuse/relay box for more than 10 seconds to reset the TCM memory, then

retest.

NOTE: Disconnecting the BACK UP RADIO fuse also cancels the radio anti-theft code, preset stations and the clock setting.

Get the customer's code number, and make note of the radio presets before removing the fuse so you can reset them.
DATA LINK CONNECTOR (16P)ProCarManuals.com

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 TC M sense s a n abnormalit y in 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 is 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 o n (II ) th e ignitio n switc h an d observ e th e indicato r light .
GAUG E ASSEMBL YSERVICE CHEC KCONNECTO R (2P )
INDICATO RLIGHT
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 throug h 1 8 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 -
minin g th e code , refe r t o th e electrica l syste m Symptom-t o Componen t Char t o n page s 14-5 6 an d 14-57 .
short
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 U P 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 TC M memory , the n
recheck .
NOTE: Disconnectin g th e BAC K U P RADI O fus e als o cancel s th e radi o anti-theft 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 .
See DTC 1
See DTC 2
See DTC1 4
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Symptom-to-Component Char t
Electrica l Syste m
Diagnosti c
Troubl e Cod e
(DTC) *
P1753
(1)
P175 8
(2)
P179 0
(3)
P179 1
(4)
P170 5
(5)
P170 6
(6)
P075 3
(7)
P075 8
(8)
P072 0
(9)
P179 2
(10)
P072 5
(11)
Indicato r
Light
Blink s
Blink s
Blinks o r
OF F
Blink s
Blink s
OFF
Blink s
Blink s
Blinks
Blink s
OFF
Sympto m
• Lock-u p clutc h doe s no t engage .
• Lock-u p clutc h doe s no t disen -
gage.
• Lock-u p clutc h doe s no t engage .
• Lock-u p clutc h doe s no t engage .
• Lock-u p clutc h doe s no t engage .
• Fail s t o shif t othe r tha n 2n d - 4t h
gears .
• Lock-u p clutc h doe s no t engage .
• Fail s t o shif t othe r tha n 2n d - 3r d
- 4t h gears .
• Lock-u p clutc h doe s no t engage .
• Fail s t o shif t (betwee n 1s t - 4t h
o r 2n d - 3r d gea r only) .
• Fail s t o shif t (stuc k in 4t h gear) .
• Fail s t o shif t (stuc k i n 1s t o r 4t h
gears) .
• Lock-u p clutc h doe s no t engage .
• Lock-u p clutc h doe s no t engage .
• Lock-u p clutc h doe s no t engage . Possibl
e Caus e
• Disconnecte d lock-u p contro l solenoi d
valv e A connecto r
• Shor t o r ope n i n lock-u p contro l
solenoi d valv e A wir e
• Fault y lock-u p contro l solenoi d valv e A
• Disconnecte d lock-u p contro l solenoi d
valv e B connecto r
• Shor t o r ope n i n lock-u p contro l
solenoi d valv e B wir e
• Fault y lock-u p contro l solenoi d valv e B
• Disconnecte d throttl e positio n (TP )
senso r connecto r
• Shor t o r ope n in T P senso r wir e
• Fault y T P senso r
• Disconnecte d vehicl e spee d senso r
(VSS ) connecto r
• Shor t o r ope n i n VS S wir e
•Fault y VS S
• Shor t i n A/ T gea r positio n switc h wir e
• Fault y A/ T gea r positio n switc h
• Disconnecte d A/ T gea r positio n switc h
connecto r
• Ope n i n A/ T gea r positio n switc h wir e
• Fault y A/ T gea r positio n switc h
• Disconnecte d shif t contro l solenoi d
valv e A connecto r
• Shor t o r ope n i n shif t contro l solenoi d
valv e A wir e
• Fault y shif t contro l solenoi d valv e A
• Disconnecte d shif t contro l solenoi d
valv e B connecto r
• Shor t o r ope n i n shif t contro l solenoi d
valv e B wir e
• Fault y shif t contro l solenoi d valv e B
• Disconnecte d countershaf t spee d sen -
so r connecto r
• Shor t o r ope n i n countershaf t spee d
senso r wir e
• Fault y countershaf t spee d senso r
• Disconnecte d engin e coolan t tempera -
ture (ECT ) senso r connecto r
• Shor t o r ope n in EC T senso r wir e
• Fault y EC T senso r
• Disconnecte d ignitio n coi l connecto r
• Shor t o r ope n i n ignitio n coi l wir e
• Fault y ignitio n coi l
Refe r t o
Pag e
14-5 8
14-6 0
14-6 2
14-6 3
14-6 4
14-6 6
14-6 8
14-7 0
14-7 2
14-7 4
14-7 5
(DTC)* : Th e DTC s i n parenthese s ar e th e code s o f th e indicato r ligh t indicate s whe n th e servic e chec k connecto r i s con -
necte d to th e specia l too l (SC S servic e connector) .
ProCarManuals.com

Diagnostic
Troubl e Cod e
(DTC) *
P1794
(13)
P178 6
(14)
P071 5
(15)
P176 8
(16)
P178 7
(18)
P074 0
(none )
P0730
(none )
Indicato r
Light
Blink s
Blinks
'95, '96 , '97
model s
OFF
'98 mode l
Blink s
Blinks
OFF
OF F
OFF
Sympto m
• N o specifi c sympto m appears .
• Transmissio n jerk s har d whe n
shifting .
• Transmissio n jerk s har d whe n
shifting .
• Lock-u p clutc h doe s no t engage .
• Fail s t o shif t (stuc k in 4t h gear) .
• Lock-u p clutc h doe s no t engage .
• Lock-u p clutc h doe s no t hav e
duty operatio n (O N OFF )
• Lock-u p clutc h doe s no t engage .
• Fail s t o shif t (betwee n 1s t -2nd,
1s t - 2n d - 3rd , 1st - 2nd - 4th , 1st
- 3r d - 4th , 2n d - 3r d - 4t h gear s
only) .
• Fail s t o shif t (stuc k in 1s t gear) .
Possibl e Caus e
• Shor t o r ope n in BARO S S (RED/BLU )
wir e betwee n B 2 termina l an d EC M
• Fault y barometri c pressur e (BARO )
sensor
NOTE : BAR O senso r i s buil t int o ECM .
• Shor t o r ope n in FA S (PNK ) wir e
betwee n B1 9 termina l an d EC M
• Fault y EC M
• Disconnecte d mainshaf t spee d senso r
connecto r
• Shor t o r ope n in mainshaf t spee d sen -
so r wir e
• Fault y mainshaf t spee d senso r
• Disconnecte d linea r solenoi d connecto r
• Shor t o r ope n in linea r solenoi d wir e
• Fault y linea r solenoi d
• Disconnecte d o r loose d P G termina l
• Shor t o r ope n in FF S (RED/GRN ) wir e
betwee n A2 4 termina l an d EC M
• Fault y EC M
• Fault y TC M
• Fault y lock-u p contro l syste m
• Fault y shif t contro l syste m
Refer t o
Pag e
14-7 6
14-77
14-7 9
14-8 1
14-8 3
14-8 4
14-8 5
(DTC)* : Th e DTC s i n parenthese s ar e th e code s o f th e indicato r ligh t indicate s whe n th e servic e chec k connecto r i s con -
necte d t o th e specia l too l (SC S servic e connector) .
If th e self-diagnosti c indicato r ligh t doe s no t blink , perfor m a n inspectio n accordin g t o th e tabl e below .
Sympto m
indicator ligh t doe s no t com e o n fo r tw o second s afte r ignitio n
switc h i s firs t turne d o n (II) .
indicato r ligh t i s o n constantl y (no t blinking ) wheneve r th e ignitio n
switch i s o n (II) .
Shif t leve r canno t b e move d fro m positio n wit h th e brak e peda l
depressed . Inspectio
n
Chec k brak e switc h signal . Ref
. pag e
14-86
14-8 8
14-8 9
NOTE :
If a custome r describe s th e sympto m fo r cod e P179 0 (3) , bu t th e indicato r ligh t i s no t blinking , P170 6 (6 ) o r P072 5
(11) , i t wil l b e necessar y t o recreat e th e sympto m b y test-driving , the n rechec k th e DTC .
Sometime s th e indicato r ligh t an d th e Malfunctio n Indicato r Lam p (MIL ) ma y com e o n simultaneously . I f so , repai r
th e PGM-F I syste m accordin g t o th e DTC , the n rese t th e memor y b y removin g th e BAC K U P RADI O fus e i n th e under -
das h fuse/rela y bo x fo r mor e tha n 1 0 seconds . Driv e th e vehicl e fo r severa l minute s a t a spee d ove r 3 0 mp h (5 0 km/h) ,
the n rechec k th e DTC .
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