low oil pressure ISUZU TF SERIES 2004 Workshop Manual

DIAGNOSIS (JR405E) 7A2-157
No. Wire
Color Pin Name Input /
OutputConnected toMeasurement
Item Measurement
Condition StandardInspection
Point at
Trouble
At other than
R range, L
range 1st gear More than 10
V Related
harness
B12 YEL Low & Reverse Brake Pressure Switch InputLow & reverse
brake pressure
switch Voltage
At R range, L
range 1st gear Less than 2VPressure
switch
Related
harness
B13 YEL/
RED Vehicle Speed Sensor InputVehicle speed
sensor Voltage (Wave
form) At run in L
range in 1 st
gear 20 km/h.
Circuit tester
(+) to B13 pin,
(-) to B5 pin. Pulse
generated (At
AC range
approx. 6.8V)Vehicle
speed sensor
B14 BLU/
BLK ATF Thermo Sensor Ground - ATF thermo
sensor Continuity Normally Continuity Related
harness
B15 BLK Ground - Ground Voltage Normally Less than 2VRelated
harness
B16 - - - - - - - -
At lock-up.
Circuit tester
(+) to B17 pin,
(-) to B5 pin. Pulse
generated (At
AC range
approx. 2.2 -
9.0V) Related
harness
B17 BLK Lock-up Duty Solenoid OutputLock-up duty
solenoid Voltage (Wave
form)
At unlock-up.
Circuit tester
(+) to B17 pin,
(-) to B5 pin. Pulse
generated (At
AC range
approx. 1.0 -
2.0V) Duty solenoid
At key switch
ON 10 – 14.5V Related
harness
B18 WHT V ign (Ignition Power Supply) Input Key switch Voltage
At key switch
OFF Less than 2V Fuse
At R range 10 – 14.5V Related
harness
B19 RED/
YEL R Range Switch Input Inhibitor switch Voltage
At other than
R range Less than 2VInhibitor
switch
At other than
3rd or 4th
gear More than 10
V Related
harness
B20 WHT/
BLK High Clutch Oil Pressure Switch InputHigh clutch
pressure switch Voltage
At 3rd or 4th
gear Less than 2VPressure
switch
At L range 10 – 14.5V Related
harness
B21 PNK/
BLK L Range Switch Input Inhibitor switch Voltage
At other than
L range Less than 2VInhibitor
switch
B22 GRY/
RED Ground Return Output Shift solenoid Continuity Normally Continuity Related
harness
At N range 10 – 14.5V Related
harness
B23 VIO Line Pressure Solenoid OutputLine pressure
solenoid Voltage
At D range
stall Less than 2V Solenoid

7A3-16 ON-VEHICLE SERVICE (JR405E)
SOLENOIDS, OIL PRESSURE SWITCH AND OIL TEMPERATURE
SENSOR
244L300003
Legend
1. High clutch oil pressure switch connector
(wire color: Gray)
2. 2-4 brake oil pressure switch connector
(wire color: Brown)
3. Low and reverse brake oil pressure switch connector
(wire color: White)
4. Low and reverse brake duty solenoid connector
(wire color: Pink and White)
5. High clutch duty solenoid connector
(wire color: Green and Gray)

6. Lock-up duty solenoid connector
(wire color: Yellow and Black)
7. 2-4 brake duty solenoid connector
(wire color: Blue and Brown)
8. Low clutch duty solenoid connector
(wire color: Orange and Black)
9. Line pressure solenoid connector
(wire color: Pink)

ON-VEHICLE SERVICE (JR405E) 7A3-19
Install or Connect
1. Align the manual valve and the manual plate of the
transmission case.
43ASSY119
2. Install the control valve assembly and tighten the 12
fixing bolts to the specified torque.

Number of bolts Length Color
10 (A) 40 mm (1.57 in) Gold
2 (B) 30 mm (1.18 in) Gold

Bolt torque : 8 N·m (69 lb·in)
3. Connect the 2 harness connectors.
4. If removed, install the oil strainer.
Refer to “Solenoids, Oil Pressure Switch and Oil
Temperature Sensor” previously in this section.
5. Install the new gasket and oil pan.
Bolt torque : 8 N·m (69 lb·in)
6. Fill the fluid.
Refer to “ATF CHANGE” in this section.
7. Connect the negative battery cable.
8. Remove the wheel blocks.

FLUSHING THE TRANSMISSION FLUID COOLER AND LINE
The fluid cooler and lines may be flushed under the
following condition. This will help prevent more trouble
after the transmission is repaired.
1. When the abnormal amount of debris are found.
2. When the abnormal wear or chips on gears and
shafts are found while overhauling.
3. When the abnormal clutch facing wear and oil
contamination are found.

Procedures
1. Block the wheels.
2. Disconnect negative battery cable.
3. Raise vehicle and support with suitable safety
stands.
4. Disconnect fluid cooler lines at transmission case
and fluid cooler.
5. Flush and back-flush the fluid cooler and lines using
solvent and compressed air.
Note:
DO NOT exceed 197 kPa (29 psi) air pressure or
damage may result to oil cooler.

6. Remove all remaining solvent from the system with
compressed air.
7. Flush the cooling system again with Automatic
Transmission Fluid (ATF).
After the final flush, connect all lines.
Cooler line joint connector torque :
44 N·m (33 lb·ft)
8. Replenish ATF
9. Start engine to test the system for the free flow o
f
fluid. If the flow is restricted, the cooler assembly o
r
lines must be replaced.
Repeated cleaning and flushing may not remove all
debris from the fluid cooler circuit.
Move the select lever through the various ranges and
return to neutral.
Check for fluid level.
If the fluid level is below the specified range, ATF
must be added.
10. Connect negative battery cable.
11. Remove safety stands.
12. Remove wheel blocks.

7A4-12 UNIT REPAIR (JR405E)

06CV19

5. Solenoid
6. Oil pressure switch Remove the 6 solenoids together and the 3 oil pressure
switchs.


07CV17

7. Control valve upper body
8. Control valve lower body
9. Separation plate
Remove the 17 bolts securing the control valve uppe
r
body, the control valve lower body, and the separation
plate.


08CV16



Separate the upper body, the lower body, and the
separation plate.
NOTE:
Take care not to drop or lose the parts at the inside of the
control valve.

Inspection


Inspect the separation plate for wear and other damage.

UNIT REPAIR (JR405E) 7A4-15
244L300003
Legend
1. High clutch oil pressure switch connector
(wire color: Gray)
2. 2-4 brake oil pressure switch connector
(wire color: Brown)
3. Low and reverse brake oil pressure
switch connector (wire color: White)
4. Low and reverse brake duty solenoid
connector (wire color: Pink and White)
5. High clutch duty solenoid connector
(wire color: Green and Gray)


6. Lock-up duty solenoid connector (wire
color: Yellow and Black)
7. 2-4 brake duty solenoid connector (wire
color: Blue and Brown)
8. Low clutch duty solenoid connector (wire
color: Orange and Black)
9. Line pressure solenoid connector (wire
color: Pink)

UNIT REPAIR (JR405E) 7A4-23

CONTROL VALVE LOWER BODY

10CV11
Legend
1. Retainer plate, spring, and steel ball
2. Retainer plate, plug, spring, and
pressure regulator valve
3. Retainer plate, spring, and high clutch
accumulator
4. Retainer plate, plug, low and reverse
brake fail valve A, and spring
5. Retainer plate, plug, spring, and fail
valve
6. Retainer plate, plug, low and reverse
brake amp valve, and spring
7. Oil pressure switch
8. Oil filter
9. Solenoid
10. Line pressure solenoid
11. Lock-up solenoid

12. Harness bracket
13. Solenoid fixing plate
14. Harness assembly
15. Retainer plate, plug, spring, and 2-4
brake fail valve A
16. Retainer plate, plug, spring, and low
clutch amp valve B
17. Retainer plate, spring, and torque
converter relief valve
18. Oil strainer
19. Control valve lower body
20. Retainer plate, spring, and 2-4 brake
solenoid accumulator
21. Oil pressure switch

UNIT REPAIR (JR405E) 7A4-27

Spring specifications
No. Valve nomenclature Free length
(mm / in) Outside
diameter (mm
/ in) Linear
diameter (mm
/ in) Number of
coils
14 Pressure relief 49.0 / 1.929 7.6 / 0.299 1.1 / 0.043 17.3
15 Pressure regulator 30.5 / 1.201 14.0 / 0.551 1.4 / 0.055 5.7
16 Low and reverse brake fail (A) 22.0 / 0.866 7.0 / 0.276 0.6 / 0.024 10.0
17 Fail 23.0 / 0.906 11.0 / 0.433 0.5 / 0.020 13.2
18 Low and reverse brake amp 19.5 / 0.768 7.9 / 0.311 0.5 / 0.020 6.9
19 2 – 4 brake fail (A) 24.8 / 0.976 8.5 / 0.335 0.9 / 0.035 7.8
20 Low clutch amp (B) 26.0 / 1.024 11.0 / 0.433 0.5 / 0.020 6.9
21
Torque converter relief More than 47.2
/ 1.858 9.2 / 0.362 1.6 / 0.063 20.2
22 2 – 4 brake solenoid accumulator 31.4 / 1.236 9.8 / 0.386 1.3 / 0.051 9.3
23 High clutch accumulator 51.0 / 2.008 6.5 / 0.256 0.8 / 0.031 23.5

Oil pressure switch
Apply compressed air (392 kPa/4.0 kg/cm2) to the oil pressure
switch to check the oil pressure switch continuity between the
connector and screw.






244L300011

Oil temperature sensor (harness assembly)
Check the oil temperature sensor resistance between harness
terminals 7 and 6 (ground).

Oil temperature sensor resistance: 2,400




2,600 ohms
(20
 )


Solenoid
Measure the resistance of each solenoid.

Resistance:
Brown connector – 3.0
 3.4 ohms (20
 C)
Gray connector – 12.0
 13.2 ohms (20
 C)
White connector – 12.2
 13.4 ohms (20
 C)

Reassembly steps

Coat the parts with ATF before installing them.

Install the control valve to the control valve lower body.

Install the oil filter to the control valve lower body.