relay ACURA TL 1995 Service Service Manual

SRS Indicato r Ligh t Wir e Connection s
SRS Indicato r Ligh t Powe r Circui t
To UNDER-DAS HFUSE/RELAY BO X
18 P CONNECTO R
To GAUG E ASSEMBL Y
DASHBOAR D WIR E HARNES S
SRS Indicato r Ligh t Contro l Circui t
To SR S UNI T
SRS MAI N HARNES S
C801
To UNDER-DAS H
FUSE/RELA Y BO X
2 P CONNECTO R
C421
C427
C60 1
C42 1 : MAI N WIR E HARNES S 3 P CONNECTO R C80 1 : SR S MAI N HARNES S 2 P CONNECTO R
C42 7 : MAI N WIR E HARNES S 16 P CONNECTO R C80 2 : SR S MAI N HARNES S 3 P CONNECTO R
C60 1 : DASHBOAR D WIR E HARNES S 16 P CONNECTO R C80 5 : SR S MAI N HARNES S 18 P CONNECTO R
C60 3 : DASHBOAR D WIR E HARNES S 18 P CONNECTO R
C61 5 : DASHBOAR D WIR E HARNES S 5 P CONNECTO R
C615
C802
MAIN WIR E HARNES S
C805
DASHBOARD WIR E
HARNES S
C615C60 3
To GAUG E ASSEMBL Y
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Engine Removal/Installation

Removal (cont'd)

7. Remove the battery cables from the under-hood fuse/

relay box.

BATTERY

CABLES

8.

9.
UNDER-HOOD

FUSE/RELAY BOX

Disconnect the engine wire harness connector on

the right (passenger's) side of the engine compart-

ment.

Remove the battery cable from the under-hood ABS

fuse/relay box.

BATTERY

CABLE

ENGINE WIRE

HARNESS

UNDER-HOOD ABS

FUSE/RELAY BOX
10. Remove the intake air duct and vacuum hose.

INTAKE AIR

DUCT

11.
VACUUM

HOSE

Remove the adjusting bolt, locknut and mounting

bolt, then remove the power steering (P/S) pump

belt and pump.

MOUNTING BOLT

10 x
1.25
mm

49 N-m (5.0 kgf-m, 36 Ibf-ft)

ADJUSTING

BOLT

P/S PUMP

BELT

LOCKNUT

8 x
1.25
mm

22 N-m (2.2 kgf-m,

16 Ibf-ft)ProCarManuals.com

II. Engine Control Module (ECM) Reset Procedure

Either of the following actions will reset the ECM.

• Use the OBD II scan tool or Honda PGM Tester to clear the ECM'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 ECM, the MIL will stay

on when the ignition switch is turned ON (II).

2. Do the ECM 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

PGM-FI System

System Description

INPUTS
ENGINE CONTROL MODULE (ECM)

OUTPUTS

Fuel Injectors

PGM-FI Main Relay (Fuel Pump)

MIL

IAC Valve

A/C Compressor Clutch Relay

Radiator Fan Relay

Condenser Fan Relay

ALT

ICM

EVAP Purge Control Solenoid

Valve

Primary HO2S Heater

Secondary H02S Heater

EGR Control Solenoid Valve

IAB Control Solenoid Valve

EVAP Bypass Solenoid Valve*2

EVAP Control Canister Vent Shut

Valve*2

*1: '95-96 models

*2: '97 - 98 models

PGM-FI System

The PGM-FI system on this model is a sequential multiport fuel injection system.

Fuel injector Timing and Duration

The ECM contains memories for the basic discharge durations at various engine speeds and manifold air flow rates. The

basic discharge duration, after being read out from the memory, is further modified by signals sent from various sensors

to obtain the final discharge duration.

Idle Air Control

Idle Air Control Valve (IAC Valve)

When the engine is cold, the A/C compressor is on, the transmission is in gear, the brake pedal is depressed, the P/S load

is high, or the alternator is charging, the ECM controls current to the IAC Valve to maintain the correct idle speed.

Ignition Timing Control

• The ECM contains memories for basic ignition timing at various engine speeds and manifold air flow rates. Ignition

timing is also adjusted for engine coolant temperature.

• A knock control system is also used. When detonation is detected by a knock sensor (KS), the ignition timing is retarded.

Other Control Functions

1. Starting Control

When the engine is started, the ECM provides a rich mixture by increasing fuel injector duration.

2. Fuel Pump Control

• When the ignition switch is initially turned on, the ECM supplies ground to the PGM-FI main relay that supplies

current to the fuel pump for two seconds to pressurize the fuel system.

• When the engine is running, the ECM supplies ground to the PGM-FI main relay that supplies current to the fuel pump.

• When the engine is not running and the ignition is on, the ECM cuts ground to the PGM-FI main relay which cuts

current to the fuel pump.

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 1,250 rpm.

• Fuel cut-off action also takes place when engine speed exceeds 7,100 rpm, regardless of the position of the throttle

valve, to protect the engine from over-revving.
CKP/TDC/CYP Sensor

CKF Sensor

MAF Sensor

ECT Sensor

IAT Sensor

TP Sensor

EGR Valve Lift Sensor

Primary HO2S

Secondary H02S

VSS

BARO Sensor

ELD

Front KS

Rear KS

Starter Signal

ALT FR Signal

Air Conditioning Signal

A/T Gear Position Signal

Battery Voltage (IGN.1)

Brake Switch Signal

PSP Switch Signal

EVAP Purge Flow Switch*1

Fuel Tank Pressure Sensor*2ProCarManuals.com

PGM-FI System

Engine Control Module (ECM)

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 ECM connector ter-

minal A7 to body ground with a

jumper wire.

3. Turn the ignition switch ON (II).
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 ECM terminal A7, or an intermittent open in the GRN/RED wire

between the ECM (A7) and the gauge assembly.

Is the MIL on?

Substitute a known-good ECM

and recheck. If symptom/indica-

tion goes away, replace the origi-

nal
ECM.
— Repair short 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.

Check for an open in the wires

(PG1, PG2 lines):

1. Turn the ignition switch ON (II).

2. Measure voltage between

body ground and ECM con-

nector terminals A12 and A25

individually.

Is there less than 1.0 V?

Repair open in the wires

between ECM (A7) and gauge

assembly.

Replace the MIL bulb.
ECM CONNECTOR A (26P)

Wire side of female terminals

Repair open in the wire(s)

between ECM and G101 (located

at left side of engine) that had

more than 1.0 V.

ECM CONNECTOR A (26P)

Wire side of female terminals
The Malfunction Indicator Lamp

(MIL) never comes on (even for

two seconds) after ignition is

turned on.

Turn the ignition switch ON (II).

JUMPER WIREProCarManuals.com

PGM-FI Syste m
Engine Contro l Modul e (ECM ) (cont'd )
(From pag e 11-53 )
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 EC M connec -
to r 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 EC M (A7 )
and MIL .
Substitut e a known-goo d EC M
an d recheck . I f symptom/indica -
tio n goe s away , replac e th e origi -
nal ECM .
(From pag e 11-53 )
I s th e fus e OK ? Repai
r shor t i n th e wir e
betwee n EC U (ECM ) (1 5 A )
fus e an d PGM-F I mai n relay .
Replac e EC U (ECM ) (1 5 A ) fuse .
Inspec t No . 2 FUE L PUM P (1 5 A )
fus e i n th e under-das h fuse/rela y
box.
Is th e fus e OK ? Repai
r shor t i n th e wir e
betwee n No . 2 FUE L PUM P
(1 5 A ) fus e an d PGM-F I mai nrelay .Replac e No . 2 FUE L PUM P(15A) fuse.
Chec k fo r a shor t i n a sensor :
1. Tur n th e ignitio n switc h ON .2. Disconnec t th e 3 P connecto r
o f eac h senso r on e a t time :
• T P senso r
• EG R valv e lif t senso r
• Fue l tan k pressur e senso r
('97-98 models )
(To pag e 11-55 )
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(From pag e 11-54 )
Doe s th e MI L g o of f momentarily ?
I s ther e batter y voltage ?
Chec k fo r a n ope n i n th e wire s
(LG1 , LG 2 lines) :
1 . Reconnec t al l senso r connec -
tors .
2 . Reconnec t th e EC 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 EC M connecto r
terminal s A2 6 an d B 9 individu -
ally .
I s ther e les s tha n 1. 0 V ?
Substitut e a known-goo d EC M
an d recheck . I f symptom/indica -
tio n goe s away , replac e th e origi -
nal ECM .
Replac e th e senso r tha t cause dthe ligh t t o g o out .
ECM CONNECTO R D (22P )
Repai r shor t t o bod y groun d
in th e wir e betwee n EC M(D10) , T P senso r an d fue l tan k
pressur e senso r ('9 7 model) .
Repai r shor t t o bod y groun d in
th e wir e betwee n EC M (D21 )
an d EG R valv e lif t sensor .
A (26P)
Repai r ope n i n th e wire(s )
betwee n EC 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 . Wir
e sid e o f femal e terminal s
EC M CONNECTOR S
A (26P)B (16P)
Repai r ope n i n th e wire(s )
betwee n EC M (A26 , B9 ) an d
G10 1 tha t ha d mor e tha n 1. 0 V . EC
M CONNECTOR S
B (16P)
Wire sid e o f femal e terminal s
Chec k fo r a n ope n i n th e wire s
(IGP1 , IGP 2 lines) :
1 . Disconnec t th e junctio n con -
nector , MA F senso r an d IA C
valv e connectors .
2. Tur n th e ignitio n switc h O N (II) .3. Measur e voltag e betwee n bod ygroun d an d EC M connecto rterminals A1 3 an d B 1 individu -
ally .I
s ther e continuity ?
Chec
k fo r a shor t i n th e wire s
(VCC1 , VCC 2 lines) :
1. Tur n th e ignitio n switc h OFF .2. Disconnec t th e EC M connec -tor D (22P) .3. Chec k fo r continuit y betwee nbody groun d an d EC M con -necto r terminal s D1 0 an d D2 1individually .
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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

ECM. When the IAC Valve is activated, the valve opens to maintain the proper idle speed.

From

PGM-FI

MAIN

RELAY

INTAKE

MANIFOLD
VARIOUS SENSORS

FAST

IDLE

THERMO

VALVE
IDLE

ADJUSTING

SCREW
ENGINE

COOLANT
ENGINE

COOLANT

IAC VALVE
ECMProCarManuals.com

Starter Switc h Signa l
This signal s th e EC M whe n th e engin e is cranking .
NOTE: Transmissio n in o r position .
A (26P)ECM CONNECTOR S
Wir e sid e o t femal e terminal s
I s ther e batter y voltage ?
Is th e fus e OK ? Repai
r shor t i n th e wir e be -
twee n th e EC M (B5 ) an d th eNo . 9 STARTE R SIGNA L (7. 5
A ) fus e o r th e PGM-F I mai n
relay .Replac e th e No . 9 STARTE R
SIGNA L (7. 5 A ) fuse .
B (16P )
Inspectio n o f Starte r Switc h Sig -nal.
Chec k fo r a n ope n o r shor t i n th e
wir e (ST S line) :
Measur e voltag e betwee n EC M
connecto r terminal s B 5 an d A2 6on th e EC M connector s wit h th e
ignitio n switc h i n th e star t posi -
tion (III) .
Starte r switc h signa l i s OK . Inspec
t th e No . 9 STARTE R SIG -
NA L (7. 5 A ) fus e in th e under-das h
fuse/rela y box .
Repai r ope n in th e wir e betwee n
the EC M (B5 ) and th e No . 9STARTE R SIGNA L (7. 5 A ) fuse .
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(From pag e 11-108 )
I s ther e a clickin g nois e fro m
th e A/ C compresso r clutch ?
Chec k th e A/ C operation :
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 wire
(AC C line) :Momentaril y connec t th e A/ C
clutc h rela y connecto r termina l
No. 2 to bod y groun d wit h ajumpe r wir e severa l times . A/
C CLUTC H RELA Y CONNECTO R (C328 )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 i n th e wir e betwee n
th e EC M (A8 ) an d th e A/ C clutc h
relay.
ECM CONNECTOR S
A (26P)B (16P)
Chec k fo r a n ope n i n th e wir e
(AC C line) :
Measur e voltag e betwee n EC M
connecto r terminal s A2 6 an d B3 . 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 EC M (B3 ) an d th e A/ C switch .
Substitut e a known-goo d EC M
an d recheck . I f symptom/indi -
catio n goe s away , replac e th e
origina l ECM .
Se e th e ai r conditione r inspec -
tion (se e sectio n 22 ).
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