Fan control ACURA TL 1995 Service Repair Manual

Troubleshooting

Radiator Fan Control Module Input Tests

NOTE: Perform the following tests with the radiator fan control module 8P connector connected, the ignition switch ON (II),

and the A/C switch OFF. If you find the cause of a problem, correct it before you continue.

RADIATOR FAN CONTROL MODULE 8P CONNECTOR

WIRE SIDE OF FEMALE TERMINALS

Terminal

No.

4

6

7

2

3

1

8

5
Wire

color

BLK

WHT/GRN

BLK/YEL

BLK/YEL

YEL/WHT

YEL

LT

GRN/YEL

ORN
Test condition

Check for voltage to body

ground.

Check for battery voltage:

Check for battery voltage:

Ignition switch - ON (II)

Check for battery voltage:

Ignition switch - ON (II)

Check for battery voltage:

Ignition switch - ON (II)

Check for battery voltage:

Ignition switch - ON (II)

Connect to body ground:

Ignition switch - ON (II)

Check for voltage.
Desired results

There should be less

than one volt.

There should be battery

voltage.

Condenser fan and radia-

tor fan should come on.

Approx. 11 V (engine oil

temperature below 198°F

[92°C])
Corrective action if desired results are

not obtained

Repair open to body ground.

Check No. 56 (10 A) fuse in the under-

hood fuse/relay box; if OK, repair open

in the WHT/GRN wire.

Check No. 4* fuse in the under-dash

fuse/relay box; if OK, repair open in the

BLK/YEL wire.

Check No. 7 (7.5 A) fuse in the under-

dash fuse/relay box; if OK, repair open in

the BLK/YEL wire.

Replace the radiator fan control module.

Before you connect the new radiator fan

control module, disconnect both fan

relays. Check for continuity between the

YEL/WHT (or YEL) wire and ground, using

the 20 scale on your ohmmeter. There

should be no continuity. If there is conti-

nuity, the new radiator fan control mod-

ule will be damaged when you connect it.

Check for an open in the LT GRN/YEL

wire between the radiator fan control

module and the condenser fan relay or

the radiator fan relay. If OK, check for an

open in the YEL/WHT wire between the

radiator fan control module and the radi-

ator fan relay, or the YEL wire between

the radiator fan control module and the

condenser fan relay. If OK, test the con-

denser fan relay or the radiator fan relay.

Faulty engine oil temperature switch,

short to body ground, or faulty radiator

fan control module.

*No. 4 (15 A):'96 model

No. 4 (20 A): '97 and '98 modelsProCarManuals.com

A/C System Service

Performance Test

The performance test will help determine if the air con-

ditioner system is operating within specifications.

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

damage. Never use compressed air to pressure test R-

134a service equipment or vehicle air conditioner sys-

tems.

Additional health and safety information may be obtained

from the refrigerant and lubricant manufacturers.

1.

2.
Connect a R-134a refrigerant Recover/Recycling/

Charging System to the vehicle, as shown, follow-

ing the equipment manufacturer's instructions.

Insert a thermometer in the center vent outlet.

Determine the relative humidity and air tempera-

ture.
Recovery/Recycling/Charging System

HIGH-PRESSURE

SIDE

LOW-PRESSURE

SIDE

3. Test conditions:

Avoid direct sunlight.

Open hood.

Open front doors.

Set the temperature control dial on MAX COOL,

the mode control switch on VENT and the recir-

culation control switch on RECIRCULATE.

Turn the A/C switch on, and the fan switch on

MAX.

Run the engine at 1,500 rpm.

No driver or passengers in vehicle

4. After running the air conditioning for 10 minutes

under the above test conditions, read the delivery

temperature from the thermometer in the dash vent

and the high and low system pressure from the A/C

gauges.ProCarManuals.com

Fan Control s
Componen t Locatio n Inde x
ENGIN E COOLAN TTEMPERATUR E (ECT )SWITC H
Test , sectio n 10
Removal , sectio n 1 0
Radiato r Fa n Control :
Whe n th e engine oil temperatur e is abov e approximatel y 198° F (92°C ) afte r th e engin e ha s stopped , th e radiato r fa n wil l ru n
fo r abou t 1 5 minutes . Th e engin e coolan t temperatur e (ECT ) switc h i s i n th e thermosta t housing . Th e engin e oi l tempera -
tur e switc h i s locate d o n th e valv e cover . Th e radiato r fa n contro l modul e is locate d behin d th e glov e box .
ENGIN E OI L TEMPERATUR ESWITCHTest, sectio n 6
Replacement , sectio n 6
Test , page 23-109
Removal , sectio n 1 0 Test
, page 23-109
Removal , sectio n 1 0 Terminals
, page 23-93
Test
, page 23-62
Test, page 23-62
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

Troubleshooting

Radiator Fan Control Module Input Tests

NOTE: Perform the following tests with the radiator fan control module 8P connector connected, the ignition switch ON (II),

and the A/C switch OFF. If you find the cause of a problem, correct it before you continue.

RADIATOR FAN CONTROL MODULE 8P CONNECTOR

WIRE SIDE OF FEMALE TERMINALS

Terminal

No.

4

6

7

2

3

1

8

5
Wire

color

BLK

WHT/GRN

BLK/YEL

YEL/BLK

YEL/WHT

YEL

LT

GRN/YEL

WHT/GRN
Test condition

Check for voltage to body

ground.

Check for battery voltage:

Check for battery voltage:

Ignition switch - ON (II)

Check for battery voltage:

Ignition switch - ON (II)

Check for battery voltage:

Ignition switch - ON (II)

Check for battery voltage:

Ignition switch - ON (II)

Connect to body ground:

Ignition switch - ON (II)

Check for voltage.
Desired results

There should be less

than one volt.

There should be battery

voltage.

Condenser fan and radia-

tor fan should come on.

Approx. 11 V (engine

coolant temperature

below 207°F [97°C])
Corrective action if desired results are

not obtained

Repair open to body ground.

Check No. 39 (10 A) fuse in the under-

hood fuse/relay box; if OK, repair open

in the WHT/GRN wire.

Check No. 4* fuse in the under-dash

fuse/relay box; if OK, repair open in the

BLK/YEL wire.

Check No. 8 (7.5 A) fuse in the under-

dash fuse/relay box; if OK, repair open in

the YEL/BLK wire.

Replace the radiator fan control module.

Before you connect the new radiator fan

control module, disconnect both fan

relays. Check for continuity between the

YEL/WHT (or YEL) wire and ground, using

the 20 k scale on your ohmmeter. There

should be no continuity. If there is conti-

nuity, the new radiator fan control mod-

ule will be damaged when you connect it.

Check for an open in the LT GRN/YEL

wire between the radiator fan control

module and the condenser fan relay or

the radiator fan relay. If OK, check for an

open in the YEL/WHT wire between the

radiator fan control module and the con-

denser fan relay, or the YEL wire between

the radiator fan control module and the

radiator fan relay. If OK, test the con-

denser fan relay or the radiator fan relay.

Faulty engine coolant temperature (ECT)

switch B, short to body ground, or faulty

radiator fan control module.

* No.4 (15 A): '95 and '96 models

No.4 (20 A): '97 and '98 modelsProCarManuals.com

Relay and Control Unit Locations

Engine Compartment (cont'd)

INTERMITTENT WIPER

RELAY

Wire colors: BLU/YEL, GRN/YEL,

BLK, GRN/BLK and BLU/WHT

A/C COMPRESSOR CLUTCH RELAY

Wire colors: RED/BLU, RED,

YEL/BLK and WHT

CONDENSER FAN RELAY

Wire colors: LT GRN/YEL,

WHT/GRN, YEL/WHT and WHT

RADIATOR FAN RELAY

Wire colors: LT GRN/YEL,

WHT/BLU, YEL and WHTProCarManuals.com

CLIMATE CONTROL UNIT

RADIATOR

FAN CONTROL

MODULE

ABS CONTROL UNIT

('95 -97 models)

KEYLESS DOOR LOCK CONTROL

UNIT ('98 model)

SECURITY CONTROL

UNIT

ABS CONTROL UNIT

('98 model)

MOONROOF OPEN RELAY

Wire colors: GRY, GRN/YEL,

GRN,
YEL and BLK
MOONROOF CLOSE RELAY

Wire colors: GRY/RED, GRN/RED,

GRN,
YEL and BLK
TRANSMISSION

CONTROL

MODULE (TCM)ProCarManuals.com

Fan Control s
Componen t Locatio n Inde x
RADIATO R FA N CONTRO L
MODUL E
Terminals , pag e 23-10 9
ENGIN E COOLAN T TEMPERATUR E
(ECT ) SWITC H B
Test , sectio n 1 0
Replacement , sectio n 1 0
RADIATO R FA N
Test , pag e 23-10 9
Removal , sectio n 1 0
CONDENSE R FA N
Test , pag e 23-10 9
Removal , sectio n 1 0
ENGIN E COOLAN T TEMPERATUR E
(ECT ) SWITC H A
Test , sectio n 1 0
Removal , sectio n 1 0
RADIATO R FA N RELA YWire colors : WHT ,
YEL , WHT/BLU ,
L T GRN/YE L
Test , pag e 23-6 2
Description :
Radiator Fa n Contro l Syste m
Whe n th e engin e coolan t temperatur e (ECT ) i s abov e approximatel y 207° F (97°C ) afte r th e engin e ha s stopped , th e radiato r
fan wil l ru n fo r abou t 1 5 minutes .
The engin e coolan t temperatur e (ECT ) switc h B is o n th e thermosta t cover , an d th e radiato r fa n contro l modul e is locate d
unde r th e righ t sid e o f th e dash .
CONDENSE R FA N RELA Y
Wir e colors : WHT , YEL/WH T
WHT/GRN , L T GRN/YE L
Test , pag e 23-6 2
ProCarManuals.com

Fan Controls

Troubleshooting

NOTE: The numbers in the table show the troubleshooting sequence.ProCarManuals.com