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Isuzu KB P190. Manual - part 1096

7A2-100 TRANSMISSION CONTROL SYSTEM (JR405E)

Faulty

gearshift schedule (different from shift

speed chart)

earshift frequently

earshift point is low

or high at all points

earshift point is low

or high at limited area

kick-

dow

gearshift

nly

4th gear is not selectable

ear is changed from 2nd to 3rd in 2 range

ear is changed from 1st to 2nd in L range

ear is changed from 3rd to 4th in 3 range

Low

max

imum speed or poor acceleration

nly

4th gear is not selectable

ise or v

ibration occurs during in R

, D

, 3, 2

or L range

Engine brake does not apply

in L range

Engine stalls before v

ehicle stops from

running

Vehicle mov

es in P range or parking is not

disengaged in other than P range

Large creeping force

Small creeping force

Large noise during idle w

ith v

ehicle stop

Judder O

ccurs at Lock U

Large Shock at Lock U

Lock U

p Point is H

igh or Low

Error, open or short circuit

Open or short circuit

Error, open or short circuit

Open or short circuit

Out of standard value

Faulty operation

Clogged passage

Slip

Seizure

Faulty operation

Separation

Faulty operation

Engine speed signal

Accelerator pedal position signal

Input shaft speed sensor

Output shaft speed sensor

Powe

r drive or 3rd start switch

Transmission range switch

TCM pow

er or ground

Transmission fluid temperature sensor

Pressure control solenoid

Torque converter clutch solenoid

Low & reverse brake solenoid

2-4 brake solenoid

High clutch solenoid

Low clutch solenoid

Ground return circuit

Low & reverse brake fluid pressure sw

itch

2-4 brake fluid pressure switch

High clutch fluid pressure sw

itch

Transmission fluid quantity

Control spool valve

High clutch solenoid accumulator

Low clutch solenoid accumulator

Low & reverse brake solenoid accumulator

2-4 brake solenoid accumulator

High clutch accumulator

2-4 brake accumulator

Pressure control solenoid hydraulic circuit

Torque converter clutch hydraulic circuit

High clutch solenoid hydraulic circuit

Low clutch solenoid hydraulic circuit

Low & reverse brake solenoid hydraulic circuit

2-4 brake solenoid hydraulic circuit

Oil cooler

Torque converter

iagnostic category

Pos

ible c

aus

Electrical

Disordered selector lever cable

Disordered transmission range sw

itch

Faulty line pressure

Faulty engine idle speed

Clutch

(brake

)

Torque converter clutch piston

draulic control

Pow

rtrain

TRANSMISSION CONTROL SYSTEM (JR405E) 7A2-101

ransmission fluid leaks from breather

ransmission fluid leaks betw

een engine

and conv

erter housing

ransmission fluid leaks betw

een conv

erter

housing and transmission case

ransmission fluid leaks betw

een

transmission case and ex

tension housing

ransmission fluid leaks from oil pan

ransmission fluid leaks from manual shaft

oil seal

ransmission fluid leaks from oil cooler pipe

joint

ransmission ov

erheat

ode lamp (pow

er driv

e or 3rd start) does

not turn O

ode lamp (pow

er driv

e or 3rd start) does

not turn O

A/T

oil temperature lamp turns O

Selector lev

r feeling is faulty

Poor fuel consumption

Shift indic

tor is

faulty

Abnormal smell

ransmission fluid quantity

is low

or high

Z10

ransmission fluid quantity

is low

or high

Z11

Abnormal transmission fluid pressure

Error, open or short circuit

Open or short circuit

Error, open or short circuit

Open or short circuit

Out of standard value

Faulty operation

Clogged passage

Slip

Seizure

Faulty operation

Separation

Faulty operation

Engine speed signal

Accelerator pedal position signal

Input shaft speed sensor

Output shaft speed sensor

Powe

r drive or 3rd start switch

Transmission range switch

TCM pow

er or ground

Transmission fluid temperature sensor

Pressure control solenoid

Torque converter clutch solenoid

Low & reverse brake solenoid

2-4 brake solenoid

High clutch solenoid

Low clutch solenoid

Ground return circuit

Low & reverse brake fluid pressure sw

itch

2-4 brake fluid pressure switch

High clutch fluid pressure sw

itch

Transmission fluid quantity

Control spool valve

High clutch solenoid accumulator

Low clutch solenoid accumulator

Low & reverse brake solenoid accumulator

2-4 brake solenoid accumulator

High clutch accumulator

2-4 brake accumulator

Pressure control solenoid hydraulic circuit

Torque converter clutch hydraulic circuit

High clutch solenoid hydraulic circuit

Low clutch solenoid hydraulic circuit

Low & reverse brake solenoid hydraulic circuit

2-4 brake solenoid hydraulic circuit

Oil cooler

Torque converter

Clutch

(brake

)

Torque converter clutch piston

draulic control

Pow

rtrain

iagnostic category

Pos

ible c

aus

Electrical

Disordered selector lever cable

Disordered transmission range sw

itch

Faulty line pressure

Faulty engine idle speed

7A2-102 TRANSMISSION CONTROL SYSTEM (JR405E)

A1: Vehicle Does Not Run in D, 3, 2 L and R Range

A2: Vehicle Does Not Run in R Range

Checks

Action

Definition:
Vehicle does not run even though the accelerator pedal is being stepped on.

Diagnosis Hints

Trouble in transmission main unit is suspected. The trouble in the transmission main
unit may originate from the input circuits or output circuits; these circuits should also be
checked to prevent a reoccurrence of the trouble.

Transmission Range Switch &
Selector Lever Cable Checks

Inspect the transmission range switch and selector lever cable for misadjusting or
disordering. Refer to On-Vehicle Service section.

Transmission Fluid Checks

Inspect the transmission fluid for the following conditions. If the transmission fluid is
extremely blacked, contaminated or smells burnt, slipping of clutch is suspected.

• Low quantity

• Contamination

• Smell

Line Pressure Checks

Inspect the line pressure in all ranges for a possible dropped pressure. Refer to Line
Pressure Test in Test Instruction section.

Stall Speed Checks

Inspect the stall speed in all ranges. Refer to Stall Test in Test Instruction section.

Control Valve Body Checks

Inspect the valve body for the following conditions.

• Faulty operation

• Sticking spool valve

• Sticking shift solenoid valve. Perform function check. Refer to On-Vehicle Service

section.

• Clogged hydraulic circuit

Torque Converter Checks

Inspect the torque converter for faulty operation or sticking.

Clutch and Brake Checks

Inspect the low clutch, reverse clutch, low one-way clutch and low & reverse brake for
slipping.

Additional Checks

• Inspect the parking mechanism for faulty operation.

• Inspect the engine for proper outputs.

Checks

Action

Definition:
Vehicle does not run in R range only. It runs correctly in forward range.

Diagnosis Hints

Trouble in transmission main unit is suspected. The trouble in the transmission main
unit may originate from the input circuits or output circuits; these circuits should also
be checked to prevent a reoccurrence of the trouble.

Transmission Range Switch &
Selector Lever Cable Checks

Inspect the transmission range switch and selector lever cable for misadjusting or
disordering. Refer to On-Vehicle Service section.

Transmission Fluid Checks

Inspect the transmission fluid for the following conditions. If the transmission fluid is
extremely blacked, contaminated or smells burnt, slipping of clutch is suspected.

• Low quantity

• Contamination

• Smell

Line Pressure Checks

Inspect the line pressure in R range for a possible dropped pressure. Refer to Line
Pressure Test in Test Instruction section.

Stall Speed Checks

Inspect the stall speed in R range. Refer to Stall Test in Test Instruction section.

TRANSMISSION CONTROL SYSTEM (JR405E) 7A2-103

A3: Vehicle Does Not Run in D, 3, 2 and L Range

B1: Vehicle Runs in N Range

Control Valve Body Checks

Inspect the valve body for the following conditions.

• Faulty operation

• Sticking spool valve

• Sticking shift solenoid valve. Perform function check. Refer to On-Vehicle Service

section.

• Clogged hydraulic circuit

Torque Converter Checks

Inspect the torque converter for faulty operation or sticking.

Clutch and Brake Checks

Inspect the reverse clutch and low & reverse brake for slipping.

Additional Checks

• Inspect the parking mechanism for faulty operation.

• Inspect the engine for proper outputs.

Checks

Action

Checks

Action

Definition:
Vehicle does not run in D, 3, 2 and L range only. It runs correctly in R range.

Diagnosis Hints

Transmission Range Switch &
Selector Lever Cable Checks

Inspect the transmission range switch and selector lever cable for misadjusting or
disordering. Refer to On-Vehicle Service section.

Transmission Fluid Checks

Inspect the transmission fluid for the following conditions. If the transmission fluid is
extremely blacked, contaminated or smells burnt, slipping of clutch is suspected.

• Low quantity

• Contamination

• Smell

Line Pressure Checks

Inspect the line pressure in forward ranges for a possible dropped pressure. Refer to
Line Pressure Test in Test Instruction section.

Stall Speed Checks

Inspect the stall speed in forward ranges. Refer to Stall Test in Test Instruction section.

Control Valve Body Checks

Inspect the valve body for the following conditions.

• Faulty operation

• Sticking spool valve

• Sticking shift solenoid valve. Perform function check. Refer to On-Vehicle Service

section.

• Clogged hydraulic circuit

Torque Converter Checks

Inspect the torque converter for faulty operation or sticking.

Clutch and Brake Checks

Inspect the low clutch and low one-way clutch for slipping.

Additional Checks

• Inspect the parking mechanism for faulty operation.

• Inspect the engine for proper outputs.

Checks

Action

Definition:
Creeping force appears in N range. Vehicle moves unless the brake pedal is stepped on in N range.

Diagnosis Hints

Transmission Range Switch &
Selector Lever Cable Checks

Inspect the transmission range switch and selector lever cable for misadjusting or
disordering. Refer to On-Vehicle Service section.

Content .. 1094 1095 1096 1097 ..