1996 ACURA RL KA9 coolant

Electronic Control System

The electronic control system consists of a Powertrain Control Module (PCM), sensors, a A/T clutch pressure control

solenoid and four solenoid valves. Shifting and lock-up are electronically controlled for comfortable driving under all con-

ditions. The PCM is located below the dashboard, under the front lower panel on the passenger's side.

PCM

Throttle Position Sensor

Signal

Engine Coolant Temperature

Sensor Signal

Indicator Light

Self-Diagnosis Signal
PGM-FI

Control System

Shift Control

Lock-up Control

A/T Control System

Self-Diagnosis

Function
Vehicle Speed Sensor

Signal

Service Check Connector

Shift Solenoid

Valve A

Shift Solenoid

Valve B

A/T Clutch Pressure Control

Solenoid Valve

Torque Converter Clutch

(Lock-up Control)

Solenoid Valve A

Torque Converter Clutch

(Lock-up Control)

Solenoid Valve B

Mainshaft Speed Sensor

Signal

Countershaft Speed

Sensor Signal
Interlock SystemProCarManuals.com

Grade Logic Control System

How it works:

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

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

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

slope.ProCarManuals.com

TCS Control Unit Terminal Arrangement

TCS CONTROL UNIT 14P CONNECTOR

Wire side of female terminals

VB: Battery Voltage

Terminal

number

1

2

3

4

5

6

7

8

9

10

11

12

13

14
Wire

color

WHT/GRN

BLU/GRY

WHT/RED

BRN/BLK

GRY/BLK

RED

GRY/WHT

LT

GRN/RED

GRY

PNK/BLK

WHT/BLK

BLU/WHT

BRN/YEL

RED/BLK
Terminal sign

(Terminal name)

FRP

(Front right pulse)

WARN1

(Warning 1)

FLP

(Front left pulse)

LG1

(Logic ground 1)

RRP

(Rear right pulse)

TCV

( traction

control valve)

RLP

(Rear left pulse)

TC-INH

(Traction control

inhibit)

STR-B

(Steering B)

TC-STB

(Traction control

standby)

TC-SW

(Traction control

switch)

VREF

(Voltage

reference)

STR-A

(Steering A)

TPS

(Throttle posi-

tion sensor)
Description

Detects right-front

wheel sensor signal

Drives TCS indicator

light (The indicator light

comes on by the

self-bias)

Detects left-front wheel

sensor signal

Ground for the logic

circuit

Detects right-rear wheel

sensor signal

Detects TCS control

valve sensor signal

Detects left-rear wheel

sensor signal

Fl TCS, TCS opera-

tion permission signal

Detects steering angle

sensor signal B

TCS Fl, TCS opera-

tion start signal

Detects TCS switch

signal

Reference voltage for

the sensors of the

PGM-FI system

Detects steering angle

sensor signal A

Detects throttle position

sensor signal
Voltage

Measurement

terminals

1-GND

2-GND

3-GND

4-GND

5-GND

6-GND

7-GND

8-GND

9-GND

10-GND

11-GND

12-GND

13-GND

14-GND
Conditions

(Ignition Switch ON (ID)

Rotate the right-front

wheel.

Indicator light ON

Indicator light OFF

Rotate the left-front

wheel.

Rotate the right-rear

wheel.

TCS control valve is

fully closed.

TCS control valve is

fully open.

Rotate the right-rear

wheel.

Permission (normal)

Inhibition (the coolant

temperature is 0°C or

below)

Failure (TCS and/or

PCM is failure)

Rotate the steering

wheel.

TCS is functioning.

TCS is not functioning.

Push the TCS switch.

Release the TCS switch.

Rotate the steering

wheel.

Throttle valve is fully

closed.

Throttle valve is fully

open.
Output

voltage

About 2.5 V

About 2 V

VB

About 2.5 V

Below 0.3 V

About 2.5 V

About 0.5V

About 4.5 V

About 2.5 V

About 2.5V

(5 V. Duty 50)

About 5 V

About 0 V

5V 0V

0V

About 5 V

VB

0V

About 5 V

5V 0V

About 0.5 V

About 4.5 VProCarManuals.com

Troubleshooting Precautions

1. In any of these cases, the TCS indicator light may come on or stay on even the TCS system is normal.

The coolant temperature is 32°F (0°C) or below.

The parking brake is applied for more than 30 seconds while the vehicle is being driven.

The tires are not inflated to the specified pressure.

The wheel sensor signal is interrupted during driving at speeds of 6 mph (10 km/h) or above due to, for example, a

vehicle spinning.

The MAP sensor, the coolant temperature sensor, the ICM or the atmospheric pressure sensor system of the PGM-FI

system is faulty.

2. TCS does not function when the TCS indicator light is ON.

3. When both the TCS indicator light and the MIL are ON, troubleshoot the PGM-FI system first.

4. When both the TCS indicator light and the ABS indicator light are ON, troubleshoot the ABS first.

5. The DTC 4-9 (ABS down) is memorized when the ABS control unit cannot output the wheel speed signal due to, for

example, a missing or blown ABS B2 (15 A) fuse. If you fail to erase the DTC of the TCS after troubleshooting the ABS,

the DTC remains in the TCS control unit memory. Therefore, be sure to test-drive the vehicle, and check the TCS indica-

tor light before starting to troubleshoot the TCS.ProCarManuals.com

Troubleshooting

TC-INH Signal (No PGM-FI DTC is indicated)

Check for a short to body ground

in the TC-INH circuit:

1. Disconnect the PCM connec-

tor C (12P) and TCS control

unit 14P connectors.

2. Check for continuity between

the PCM connector C (12P) ter-

minal No. 9 and body ground.

Is there continuity?

Check the PCM:

1. Connect the PCM connector C

(12P).

2. Start the engine.

3. Measure the voltage between

the PCM connector C (12P) ter-

minal No. 9 and body ground.

Does the tester needle swing

to about 2.5 V?

Check for an open in the TC-INH

circuit:

Measure the voltage between the

TCS control unit 14P connector

terminal No. 8 and body ground.

Does the tester needle swing

to about 2.5 V?

Check for loose TCS control unit

connectors. If necessary, substi-

tute a known-good TCS control

unit and recheck.
PCM CONNECTOR C (12P)

Repair short to body ground in

the wire between the PCM and

TCS control unit.
Wire side of female terminals

NOTE: Check under the following condi-

tions.

The coolant temperature is above 32°F

(0°C).

The MIL does not come on.

NOTE: Use the 10 V range or a similar

range in an analog tester.

Check for loose PCM connectors.

If necessary, substitute a known-

good PCM and recheck.

NOTE: Check under the following condi-

tions.

The coolant temperature is above 32°F

(0°C).

The MIL does not come on.

NOTE: Use the 10 V range or a similar

range in an analog tester.
TCS CONTROL UNIT UP CONNECTOR

Repair open in the wire between

the PCM and TCS control unit.

Wire side of female terminalsProCarManuals.com

Both Fans Low Speed

Both fans do not run at low speed

(but both fans run at high speed).

Check for an open in the wire:

1. Remove the radiator fan main

relay from the under-hood

relay box A.

2. Disconnect the radiator fan 2P

connector.

3. Check for continuity between

the No. 2 terminal of the radi-

ator fan main relay 5P socket

and the No. 2 terminal of the

radiator fan 2P connector.
NOTE: It is normal for both fans to run at high speed when the system pressure is above

1,520 kPa (15.5 kgf/cm2, 220 psi), or when the engine coolant temperature is above 194°F

(90°C).

RADIATOR FAN 2P CONNECTOR

Wire side of female terminals

RADIATOR FAN MAIN RELAY 5P SOCKET

Is there continuity?
Repair open in the wire between

the radiator fan main relay and

the radiator fan.

Replace the radiator fan main

relay.ProCarManuals.com