Isuzu D-Max / Isuzu Rodeo (TFR/TFS). Manual — part 1776

DIAGNOSIS 7A2-155

DIAGNOSIS 7A2-156

TCM VOLTAGE CHECK

TCM voltage check is done to check for transmission and TCM

problems which cannot be detected by self-diagnosis.

Additionally, it severs as a back-up check for self-diagnosis.

Measure the voltage drop and make a continuity test for each of
sensors, solenoids and switches.

If the voltage is within the specified range and continuity exists,
that particular area of the TCM and transmission assembly is
normal.

If voltage deviation or lack of continuity is discovered, disconnect
the applicable parts and check of them individually.

Inspection Tool

Use a circuit tester and an oscilloscope to measure voltage and
circuit continuity.

Insert the test probes from the connector wiring side. TCM
terminals are extremely small.

Wrap a piece of thin wire around the probe of tester.

This will make measurement easier.

TCM Pin Assignment

Connect to White Connector Connect to Grey Connector

No.

Wire

Color

Pin Name

Input /

Output

Connected to

Measurement

Item

Measurement

Condition

Standard

Inspection

Point at
Trouble

A1

RED

V BATT (Battery Back-up Power

Supply)

Input

Battery Voltage

-

Battery

voltage

Related

harness

At P range

Battery

voltage

Related

harness

A2

YEL/

VIO

P Range Switch

Input

Inhibitor switch

Voltage

At other than

P range

Less than 2V

Inhibitor

switch

At brake

stepped

Battery

voltage

Related

harness

A3

RED Brake

Switch

Input

Brake

switch

Voltage

At brake no

stepped

Less than 2V Brake switch

At lamp OFF

Battery

voltage

Related

harness

A4

PNK/

WHT

3rd Start Indicator Lamp

Output 3rd start lamp

Voltage

At lamp ON

Less than 2V Lamp

A5

GRN

K-line signal (Tech 2 serial

communication)

Input/

Output

Tech 2

-

-

-

Related

harness

A6

- -

- -

-

-

-

-

DIAGNOSIS 7A2-157

No.

Wire

Color

Pin Name

Input /

Output

Connected to

Measurement

Item

Measurement

Condition

Standard

Inspection

Point at
Trouble

Related

harness

Engine

Speed

Sensor

A7

BLK/

RED

Engine Speed Sensor

Input

ECM

Voltage (Wave

form)

At 1500rpm.

Circuit tester

(+) to A7 pin,

(-) to B5 pin.

Pulse

generated

(At AC range

approx. 5.5

V)

ECM

A8

- -

- -

-

-

-

-

A9

- -

- -

-

-

-

-

Related

harness

Speed

sensor

Speed meter

A10

BLK/

YEL

Vehicle Speed Sensor Out (2WD Only) Output Speed meter

Voltage (Wave

form)

At run in L

range in 1st

gear 20 km/h.

Circuit tester

(+) to A10 pin,

(-) to B5 pin.

Pulse

generated

(At AC range

approx. 6.5

V)

TCM

At switch

pushed

Less than 2V

Related

harness

A11

GRN/

WHT

3rd Start Select Switch

Input

3rd start switch

Voltage

At switch off

Battery

voltage

3rd start

switch

At 4L

Less than 2V

Related

harness

A12

BLU/

WHT

4L Mode Switch (4WD Only)

Input

Transfer control

unit

Voltage

At other than

4L

Battery

voltage

4L switch

A13

- -

- -

-

-

-

-

A14

- -

- -

-

-

-

-

A15

- -

- -

-

-

-

-

At fully close

Off duty 10%

Related

harness

ECM

A16

RED/

WHT

Throttle Position Sensor

Input

ECM

Wave form

(140Hz Duty

signal) *1

At fully open

Off duty 90%

Throttle

position

sensor

At 3 range

Battery

voltage

Related

harness

A17

BLK/

GRN

3 Range Switch

Input

Inhibitor switch

Voltage

At other than

3 range

Less than 2V

Inhibitor

switch

At key switch

ON

Battery

voltage

Related

harness

A18

YEL/

BLK

DIAG Switch

Input

Data link

connector

Voltage

At short circuit

of DIAG

switch

Less than 2V

At lamp OFF

Battery

voltage

Related

harness

A19

ORG/

BLU

A/T OIL TEMP Indicator Lamp

Output

AT OIL TEMP

indicator lamp

Voltage

At lamp ON

Less than 2V Lamp

At lamp OFF

Battery

voltage

Related

harness

A20

GRN/

YEL

CHECK TRANS Indicator Lamp

Output

CHECK TRANS

indicator Lamp

Voltage

At lamp ON

Less than 2V Lamp

At lamp OFF

Battery

voltage

Related

harness

A21

PNK POWER DRIVE Indicator Lamp

Output

POWER DRIVE

indicator lamp

Voltage

At lamp ON

Less than 2V Lamp

A22

- -

- -

-

-

-

-

A23

- -

- -

-

-

-

-

DIAGNOSIS 7A2-158

No.

Wire

Color

Pin Name

Input /

Output

Connected to

Measurement

Item

Measurement

Condition

Standard

Inspection

Point at
Trouble

At lamp OFF

Battery

voltage

Related

harness

A24

GRN/

YEL

Power Drive Select Switch

Input

Power drive

switch

Voltage

At lamp ON

Less than 2V Lamp

At other than

2nd or 4th

gear

More than 10

V

Related

harness

B1

RED/

YEL

2-4 Brake Pressure Switch

Input

2-4 brake

pressure switch

Voltage

At 2nd or 4th

gear

Less than 2V

Pressure

switch

At 2 range

Battery

voltage

Related

harness

B2

PNK/

BLK

2 Range Switch

Input

Inhibitor switch

Voltage

At other than

2 range

Less than 2V

Inhibitor

switch

Input

Related

harness

B3

BRN/

RED

Turbine Sensor

Turbine sensor

Voltage (Wave

form)

At run in L

range in 1st

gear 20 km/h.

Circuit tester

(+) to B3 pin,

(-) to B5 pin.

Pulse

generated

(At AC range

approx. 6.2

V)

Turbine

sensor

ATF temp.

20

°

C

Approx. 1.55

V

Related

harness

B4

BLU ATF

Thermo

Sensor

Input

ATF thermo

sensor

Voltage

ATF temp.

60

°

C

Approx. 0,7V

Thermo

sensor

B5

BLK Ground

-

Ground

Voltage

Normally

Less than 2V

Related

harness

Related

harness

B6

BLU/

BLK

Low & Reverse Brake Duty Solenoid

Output

Low & reverse

brake duty

solenoid

Voltage (Wave

form)

P, N range.

Circuit tester

(+) to B6 pin,

(-) to B22 pin.

Pulse

generated

(At AC range

approx.

6.8V)

Duty solenoid

Related

harness

B7

BLK/

YEL

2-4 Brake Duty Solenoid

Output

2-4 brake duty

solenoid

Voltage (Wave

form)

P, N range.

Circuit tester

(+) to B7 pin,

(-) to B22 pin.

Pulse

generated

(At AC range

approx.

6.8V)

Duty solenoid

Related

harness

B8

RED High Clutch Duty Solenoid

Output

High clutch duty

solenoid

Voltage (Wave

form)

P, N range.

Circuit tester

(+) to B8 pin,

(-) to B22 pin.

Pulse

generated

(At AC range

approx.

6.8V)

Duty solenoid

Related

harness

B9

WHT/

RED

Low Clutch Duty Solenoid

Output

Low clutch duty

solenoid

Voltage (Wave

form)

4th gear in D

range. Circuit

tester (+) to

B9 pin, (-) to

B22 pin.

Pulse

generated

(At AC range

approx.

6.8V)

Duty solenoid

At N range

Battery

voltage

Related

harness

B10

RED/

BLK

N Range Switch

Input

Inhibitor switch

Voltage

At other than

N range

Less than 2V

Inhibitor

switch

At D range

Battery

voltage

Related

harness

B11

BLU D Range Switch

Input

Inhibitor switch

Voltage

At other than

D range

Less than 2V

Inhibitor

switch