1995 ACURA TL charging

Charging Syste m
Troubleshootin g
If th e chargin g syste m ligh t doe s no t com e o n o r doe s no t g o off , o r th e batter y i s dea d o r low , tes t th e followin g item s i n
th e orde r liste d below :
1 . Batter y (se e pag e 23-56 )
2 . Chargin g Syste m Ligh t
3. Voltag e Chec k
4. Alternator/Regulato r
(To page 23-82 )
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Charging Syste m
Troubleshootin g (cont'd )
(From page 23-81 )
Check th e alternator/regulato r
(se e pag e 23-83 ).
Chec k th e alternator/regulato r
(se e pag e 23-83 ).
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Charging Syste m
Troubleshootin g (cont'd )
(From page 23-83 )
CAUTION: Th e voltag e wil l ris e quickl y whe n th e alternato r i s full-fielded . D o no t allo w
th e voltag e to excee d 1 8 V ; i t ma y damag e th e electrica l system .
NOTE : Attac h a prob e t o th e VAT-4 0 ful l fiel d tes t lead , an d inser t th e prob e int o th e ful l
fiel d acces s hol e a t th e bac k o f th e alternator . Switc h th e fiel d selecto r t o th e " A (Ground) "
positio n momentarily , an d chec k th e amperag e reading .
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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

Idle Contro l Syste m
Alternato r (ALT ) F R Signa l
This signal s th e EC M whe n th e Alternato r (ALT ) i s charging .
Is ther e approx . 5 V ?
Chec k th e operatio n o f th e ALT :
1 . Tur n th e ignitio n switc h OFF .
2 . Reconnec t th e AL T GR N 4 P
connecto r t o th e ALT .
3 . 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 radiato r fa n
come s on , the n le t i t idle .
4 . Measur e voltag e betwee n EC M
connecto r terminal s D 5 an d A26 .
Doe s th e voltag e decreas e whe n
headlight s an d rea r defogge r ar e
turne d on ?
Chec k fo r a n ope n in th e wir e (AL T
F line) :
1. Tur n th e ignitio n switc h OFF .2. Disconnec t th e negativ e bat -
ter y cabl e fro m th e battery .
3 . Disconnec t th e EC M connec -
tor D (22P) .4. Disconnec t th e GR N 4 P con -
necto r fro m th e ALT .
5 . Connec t th e AL T 4 P connecto r
termina l No . 4 to bod y groun d
with a jumpe r wire .6. Chec k fo r continuit y betwee nbody groun d an d EC M con -necto r termina l D5 .
I s ther e continuity ?
Se e th e AL T inspectio n (se e
sectio n 23 ). EC
M CONNECTOR S
A (26P)D (22P)
Wire sid e o f femal e terminal s
D (22P)
Repai r shor t i n th e wir e betwee nthe EC M (D5 ) and th e ALT .
ALT F R signa l i s OK .
ALT GR N 4P CONNECTO R (C127 )
JUMPE R WIR E
Wir e sid e o f femal e terminal s
Repai r ope n wir e betwee n th e
ECM (D5 ) and th e ALT .
ECM CONNECTO R D (22P )
Wir e sid e o f femal e terminal s
Substitut
e a known-goo d EC M
an d recheck . I f prescribe d voltag e
i s no w available , replac e th e origi -
nal ECM .
Is ther e continuity ?
Chec
k fo r a shor t i n th e wir e (AL T
F line) :
1 . Tur n th e ignitio n switc h OFF .
2 . Disconnec t th e negativ e bat -
ter y cabl e fro m th e battery .
3 . Disconnec t th e EC M connecto r
D (22P) .4. Chec k fo r continuit y betwee n
bod y groun d an d EC M con -
necto r termina l D5 .
Chec
k fo r a shor t i n th e wir e (AL T
F line) :
1 . Disconnec t th e GR N 4 P con -
necto r fro m th e ALT .
2 . Tur n th e ignitio n switc h O N (II) .
3 . Measur e voltag e betwee n EC M
connecto r terminal s D 5 an d A26 .
Inspectio
n o f AL T F R Signal .
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Description

Outline

The air conditioner system removes heat from the passenger compartment by circulating refrigerant through the system

as shown below.

High-temperature/

high-pressure gas

Suction and compression
Radiation of heat
High-temperature/

high-pressure liquid

Traps debris,

and removes

moisture
High-temperature/

high-pressure liquid

COMPRESSOR

Less moisturized

low-pressure vapor
CONDENSER

Absorption of heat

EVAPORATOR
More liquidified

low-pressure vapor
RECEIVER/DRYER

EXPANSION VALVE

HEATER/EVAPORATOR/BLOWER
UNIT

CONDENSER
SUCTION LINE

COMPRESSOR

RECEIVER/DRYER

DISCHARGE LINE

This vehicle uses HFC-134a (R-134a) refrigerant which does not contain chlorofluorocarbons. Pay attention to the follow-

ing service items:

Do not mix refrigerants CFC-12 (R-12) and HFC-134a (R-134a). They are not compatible.

Use only the recommended polyalkyleneglycol (PAG) refrigerant oil (ND-OIL 8) designed for the R-134a compressor.

Intermixing the recommended (PAG) refrigerant oil with any other refrigerant oil will result in compressor failure.

All A/C system parts (compressor, discharge line, suction line, evaporator, condenser, receiver/dryer, expansion valve.

O-rings for joints) have to be proper for refrigerant R-134a. Do not confuse with R-12 parts.

Use a halogen gas leak detector designed for refrigerant R-134a.

R-12 and R-134a refrigerant servicing equipment are not interchangeable. Use only a Recovery/Recycling/Charging System

that is U.L.-listed and is certified to meet the requirements of SAE J2210 to service R-134a air conditioning systems.

Always recover the refrigerant R-134a with an approved Recovery/Recycling/Charging System before disconnecting

any A/C fitting.
RECEIVER LINE

CONDENSER LINEProCarManuals.com

A/C Syste m Servic e
Pressur e Tes t Char t
NOTE : Performanc e Tes t i s o n pag e 22-68 .
Test result s
Discharg e (high )
pressur e abnor -
mally hig h
Discharg e pres -
sur e abnormall y
low
Suctio n (low )
pressur e abnor -
mally lo w
Suctio n pres -
sur e abnormall y
high
Suctio n an d dis -
charg e pres -
sure s abnormall y
hig h
Suctio n an d dis -
charg e pressur e
abnormall y lo w
Refrigeran t leak s
Relate d symptom s
After stoppin g compressor, pres-
sur e drop s t o abou t 20 0 kP a
(2.0 kgf/cm2, 2 8 psi ) quickly , an d
the n fall s gradually .
Reduce d o r n o ai r flo w throug h
condense r
Lin e to condense r i s excessivel y
hot.
Hig h an d lo w pressure s ar e bal -
ance d soo n afte r stoppin g compres -
sor . Lo w sid e is highe r tha n normal .
Outle t o f expansio n valv e is no t
frosted , lo w pressur e gaug e indi -
cate s vacuum .
Expansio n valv e is no t frosted , an d
low-pressur e lin e is no t cold . Low -
pressur e gaug e indicate s vacuum .
Discharg e temperatur e is low , an d
th e ai r flo w fro m vent s i s restricted .
Expansio n valv e is frosted .
Receiver/drye r outle t i s cool , an d
inle t i s war m (shoul d b e war m
durin g operation) .
Low-pressur e hos e an d chec k
join t ar e coole r tha n th e tempera -
tur e aroun d evaporator .
Suctio n pressur e is lowere d whe n
condense r i s coole d b y water .
Hig h an d lo w pressur e ar e equal -
ize d a s soo n a s th e compresso r i s
stopped , an d bot h gauge s fluctu -
ate whil e running .
Reduced ai r flo w throug h con -
denser .
Low-pressur e hos e an d meta l en d
area s ar e coole r tha n evaporator .
Temperatur e aroun d expansio n
valv e i s to o lo w compare d wit h
tha t aroun d receiver/dryer .
Compresso r clutc h i s dirty .
Compresso r bolt(s ) ar e dirty .
Compresso r gaske t i s we t wit h oil . Probabl
e caus e
Ai r i n syste m
• Clogge d condense r o r
radiato r fin s
• Condense r o r radiato r fa n
no t workin g properl y
Restricte d flo w o f refriger -
an t i n syste m
• Fault y compresso r dis -
charg e valv e
• Fault y compresso r sea l
• Fault y expansio n valv e
• Moistur e i n syste m
• Froze n expansio n valv e
• Fault y expansio n valv e
Froze n evaporato r
Clogge d expansio n valv e
Clogge d receiver/drye r
• Expansio n valv e ope n to o
lon g
• Loos e expansio n capillar y
tub e
Excessiv e refrigeran t i n sys -
tem
• Fault y gaske t
• Fault y hig h pressur e valv e
• Foreig n particl e stuc k in
high-pressur e valv e
• Clogge d condense r o r
radiato r fin s
• Condense r o r radiato r fa n
no t workin g properl y
Clogge d o r kinke d lo w pres -
sur e hos e part s
Clogge d high-pressur e lin e
Compresso r shaf t sea l leakin g
Leakin g aroun d bolt(s )
Gaske t leakin g Remed
y
Recover , evacuate , an d
recharg e wit h specifie d amount .
Evacuation : se e pag e 22-8 1
Charging : se e pag e 22-8 2
• Clean .
• Chec k voltag e an d fa n rpm .
• Chec k fa n direction .
Restricte d line s
Replac e th e compressor .
• Replace .
• Recover , evacuate , an d
recharg e wit h specifie d
amount .
Replac e th e expansio n valve .
Run th e fa n wit h compresso r
off, the n chec k A/ C thermostat .
Clea n o r replace .
Replace .
Repair o r replace .
Recover , evacuate , an d
recharg e wit h specifie d amount .
Replac e th e compressor .
• Clea n condense r an d radia -
tor.
• Chec k voltag e an d fa n rpm .
• Chec k fa n direction .
Repai r o r replace .
Repai r o r replace .
Replac e th e compressor .
Tighte n bolt(s ) o r replac e com -
pressor .
Replac e th e compressor .
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Recovery

Use only service equipment that is U.L.-listed and is cer-

tified to meet the requirements of SAE J2210 to remove

HFC-134a (R-134a) from the air conditioner system.

CAUTION: Exposure to air conditioner refrigerant and

lubricant vapor or mist can irritate eyes, nose and

throat. Avoid breathing the air conditioner refrigerant

and lubricant vapor or mist.

If accidental system discharge occurs, ventilate work

area before resuming service.

R-134a service equipment or vehicle air conditioner sys-

tems should not be pressure tested or leak tested with

compressed air.

Some mixtures of air and R-134a have been

shown to be combustible at elevated pressures and can

result in fire or explosion causing injury or property dam-

age. Never use compressed air to pressure test R-134a

service equipment or vehicle air conditioner systems.

Additional health and safety information may be obtained

from the refrigerant and lubricant manufacturers.

1. Connect a R-134a refrigerant Recovery/Recycling/

Charging System to the vehicle, as shown, following

the equipment manufacturer's instructions.

2. Measure the amount of refrigerant oil removed from

the A/C system after the recovery process is com-

pleted.

NOTE: Be sure to install the same amount of new

refrigerant oil back into the A/C system before charg-

ing.
Recovery/Recycling/Charging System

HIGH-PRESSURE

SIDE
LOW-PRESSURE

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