1995 ACURA TL engine coolant

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

GRADE LOGIC CONTROL SYSTEM

How it works:

The TCM compares actual driving conditions with driving conditions memorized in the TCM, based on the input from the

vehicle speed sensor, throttle position sensor, engine coolant temperature sensor, barometric pressure sensor, brake

switch signal and shift lever position signal, to control shifting while a vehicle is ascending or descending a slope, or

reducing speed.

SENSORS

SIGNALS DETECTED

TCM
Electronic Control System (cont'd)ProCarManuals.com

Component Locations

BRAKE SWITCH

TRANSMISSION CONTROL

MODULE (TCM)

ENGINE CONTROL

MODULE (ECM)

THROTTLE POSITION (TP)

SENSOR

ENGINE COOLANT

TEMPERATURE (ECT)

SENSOR
LOCK-UP CONTROL SOLENOID

VALVE ASSEMBLY

MAINSHAFT SPEED SENSOR

COUNTERSHAFT SPEED

SENSOR

VEHICLE SPEED

SENSOR (VSS)
AUTOMATIC TRANSAXLE (A/T)

GEAR POSITION SWITCH

SHIFT CONTROL SOLENOID

VALVE ASSEMBLY*

LINEAR SOLENOID*

*: Located in transmission.ProCarManuals.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

Ignition Syste m
Descriptio n
Ignition Timin g Control :
Th e programme d ignitio n (PGM-IG ) use d i n thi s engin e provide s optimu m contro l o f ignitio n timing . A microcompute r
determine s th e timin g i n respons e t o engin e spee d an d intak e ai r flo w mass . Th e inpu t signal s ar e transmitte d b y th e
TDC/CKP/CY P sensor , throttl e positio n (TP ) sensor , engine coolant temperatur e (ECT ) sensor , an d MA F sensor . Thi s sys -
tem , whic h i s no t dependen t o n a governo r o r vacuu m diaphragm , i s capabl e o f settin g lea d angle s wit h complicate d char -
acteristic s whic h canno t b e provide d b y conventiona l governor s o r diaphragms .
Basi c Control :
The contro l uni t ha s store d withi n it th e optimu m basi c ignitio n timin g fo r operatin g condition s base d upo n engin e spee d
and intak e ai r flo w mass . Wit h compensatin g signal s fro m sensors , th e syste m determine s optimu m ignitio n timin g an d
duratio n fo r ambien t condition s an d send s voltag e pulse s t o th e ICM .
Compensatio n of ignitio n timing :
Compensatio n Ite m
Idlin g
Compensatio n a t warm-u p
ECT compensatio n Relate
d Senso r an d Informatio n
TDC/CKP/CY P senso r
MAF senso r
ECT senso r
ECT senso r
Descriptio n
Ignition timin g i s controlle d t o th e targe t spee d
wit h compensatio n accordin g t o th e idlin g speed .
La g angl e is adjuste d accordin g t o warm-u p con -
dition s t o brin g abou t a goo d balanc e betwee n
operating performanc e an d exhaus t ga s level .
Compensatio n fo r lea d angl e a t lo w engin e
coolan t temperatur e an d la g angl e a t hig h engin e
coolan t temperature .
Control a t Start :
Ignitio n timin g is fixe d a t 5 ° BTD C fo r cranking . Th e crankin g is detecte d b y th e TD C senso r (crankin g rpm ) an d starte r signal .
ProCarManuals.com

Charging System

Description

To improve fuel economy, the alternator control system within the ECM changes the voltage generated at the alternator in

accordance with driving conditions.

Throttle position (TP) sensor

Engine coolant temperature

(ECT) sensor

Intake air temperature (IAT)

sensor

TDC/CKP/CYP sensor

Vehicle speed sensor (VSS)

ELD

Air conditioning signal
ECM

Alternator

STARTER SWITCH ON
Generated voltage decreases from 14.0 V to 12.5 V

AND

ELECTRICAL LOAD below 15 A

and

VEHICLE SPEED between 9 mph (15 km/h) and

44 mph (70
km/h)

and

ENGINE SPEED between 1,100 rpm and 3,000 rpm

and

ENGINE COOLANT TEMPERATURE above 176°F

(80°C)

and

A/C SWITCH OFF

and

INTAKE AIR TEMPERATURE above 65°F (18°C)
AND

FUEL CUT-OFF CON-

TROL function is not

engaged.ProCarManuals.com