2004 ISUZU TF SERIES low oil pressure

POWER-ASSISTED STEERING SYSTEM 3B-7


Power Steering System Test
Test Procedure
F02RX002
Legend
(1) Bolt
(2) Hose
(3) Power Steering Unit
(4) Power Steering Pump


Test of fluid pressure in the power steering system is
performed to determine whether or not the oil pump and
power steering unit are functioning normally.
The power steering system test is used to identify and
isolate hydraulic circuit difficulties. Prior to performing
this test, the following inspections and corrections, i
f
necessary, must be made.


Inspect pump reservoir for proper fluid level.


Inspect pump belt for proper tension.


Inspect pump driver pulley condition.
1. Place a container under the pump to catch the fluid
when disconnecting or connecting the hoses.
2.
With the engine NOT running, disconnect the
pressure hose at the power steering pump and
install power steering tester 5-8840-0135-0 as
shown in the illustration. The gage must be between
the shutoff valve and pump. Open the shutoff valve.
3. Check the fluid level. Fill the reservoir with powe
r
steering fluid, to the "Full" mark. Start the engine,
then turn the steering wheel and momentarily hold it
against a stop (right or left). Turn the engine off and
check the connections at tester for leakage.
4. Bleed the system. Refer to Bleeding the Powe
r
Steering System in this section.
5. Start the engine and check the fluid level. Add
power steering fluid if required. When the engine is
at normal operating temperature, increase engine
speed to 1500 rpm.
CAUTION: Do not leave shutoff valve fully closed
for more than 5 seconds, as the pump could
become damaged internally.

3B-8 POWER-ASSISTED STEERING SYSTEM

6. Fully close the shutoff valve. Record the highest
pressures.


If the pressure recorded is within 9300-9800 kPa
(95-100 kg/cm
2/1350-1420 psi), the pump is
functioning within its specifications.


If the pressure recorded is higher than 9800 kPa
(100 kg/cm
2/1420 psi), the valve in the pump is
defective.


If the pressure recorded is lower than 9300 kPa (95
kg/cm
2/1350 psi), the valve or the rotating group in
the pump is defective.
7. If the pump pressures are within specifications,
leave the valve open and turn (or have someone
else turn) the steering wheel fully in both directions.
Record the highest pressures and compare with the
maximum pump pressure recorded in step 6. If this
pressure cannot be built in either side of the powe
r
steering unit, the power steering unit is leaking
internally and must be replaced.
8. Shut the engine off, remove the testing gauge.
9. Reconnect the pressure hose, check the fluid level
and make the needed repairs.
10. If the problem still exists, the steering and fron
t
suspension must be thoroughly examined.

Maintenance
The hydraulic system should be kept clean and fluid
level in the reservoir should be checked at regula
r
intervals and fluid added when required. Refer to
Recommended Fluids and Lubricants in General
Information section for the type of fluid to be used and
the intervals for filling.
If the system contains some dirt, flush it as described in
this section. If it is exceptionally dirty, the pump must be
completely disassembled before further usage. (The
steering unit cannot be disassembled.)
All tubes, hoses, and fittings should be inspected for
leakage at regular intervals. Fittings must be tight. Make
sure the clips, clamps and supporting tubes and hoses
are in place and properly secured.
Power steering hoses and lines must not be twisted,
kinked or tightly bent. Air in the system will cause
spongy action and noisy operation. When a hose is
disconnected or when fluid is lost, for any reason, the
system must be bled after refilling. Refer to Bleeding the
Power Steering System in this section.


Inspect belt for tightness.


Inspect pulley for looseness or damage. The pulle
y
should not wobble with the engine running.


Inspect hoses so they are not touching any othe
r
parts of the vehicle.


Inspect fluid level and fill to the proper level.

Fluid Level
1. Run the engine until the power steering fluid
reaches normal operating temperature, about 55
C (130
F), then shut the engine off.
2. Check the level of fluid in the reservoir.
3. If the fluid level is low, add power steering fluid as
specified in General Information to the proper level
and install the receiver cap.
4. When checking the fluid level after the steering
system has been serviced, air must be bled from
the system. Refer to Bleeding the Power Steering
System in this section.

Bleeding The Power Steering System
When a power steering pump or unit has been installed,
or an oil line has been disconnected, the air that has
entered the system must be bled out before the vehicle
is operated. If air is allowed to remain in the powe
r
steering fluid system, noisy and unsatisfactory operation
of the system may result.

Bleeding Procedure
When bleeding the system, and any time fluid is added
to the power steering system, be sure to use only powe
r
steering fluid as specified in General Information.
1. Fill the pump fluid reservoir to the proper level and
let the fluid settle for at least two minutes.
2. Start the engine and let it run for a few seconds. Do
not turn the steering wheel. Then turn the engine
off.
3. Add fluid if necessary.
4. Repeat the above procedure until the fluid level
remains constant after running the engine.
5. Raise and support the front end of the vehicle so
that the wheels are off the ground.
6. Start the engine. Slowly turn the steering wheel right
and left, lightly contacting the wheel stops.
7. Add power steering fluid if necessary.
8. Lower the vehicle, set the steering wheel at the
straight forward position after turning it to its full
steer positions 2 or 3 times, and stop the engine.
9. Check the fluid level and refill as required.
10. If the fluid is extremely foamy, allow the vehicle to
set a few minutes, then repeat the above procedure.

Flushing The Power Steering System
1. Raise and support the front end of the vehicle off
the ground until the wheels are free to turn.
2. Remove the fluid return line at the pump inlet
connector and plug the connector port on the pump.
Position the line toward a large container to catch
the draining fluid.
3. While running the engine at idle, fill the reservoi
r
with new power steering fluid. Turn the steering
wheel in both directions. Do not contact or hold the
steering wheel to the wheel stops. This will cause
the pump to go to pressure relief mode, which ma
y
cause a sudden fluid overflow at the reservoir.

POWER-ASSISTED STEERING SYSTEM 3B-21

Power Steering Pump and Associated Parts (C24SE)
RTW33BLF000801

Legend
(1) Pump Assembly
(2) Hose, Suction
(3) Hose, Flexible

(4) Bolt
(5) Connector, Pressure switch

Removal
1. Remove the drive belt.
2. Remove the pulley
3. Place a drain pan below the pump.
4. Disconnect the suction hose.
5. Disconnect the flexible hose.
6. Disconnect the oil pressure switch connector.
7. Remove the power steering fixing bolt and remove
the pump assembly.

Installation
1. Install the pump assembly to the pump braket,
tighten the fixing bolt to the specified torque.
Torque: 34-46 N·m (3.5-4.7 kg·m/25-34 lb ft)
2. Connector the oil pressure switch connector.
3. Install the flexible hose.
Tighten the eye bolt to specified torque.
Torque: 49-59 N·m (5.0-6.0 kg·m/36-43 lb ft)
4. Install the pulley and tighten the bolt to the specified
torque.
Torque: 69-88 N·m (7.0-9.0 kg·m/51-65 lb ft)

5. Install the drive belt.
6. Connect the suction hose, then fill and bleed
system.
Refer to Bleeding the Power Steering System in this
section.

3B-24 POWER-ASSISTED STEERING SYSTEM

Side Plate
The sliding faces of parts must be free from step wear
(more than 0.01 mm), which can be felt by the finger
nail. The parts with minor scores may be reused after
lapping the face.

Valve
The sliding face of the valve must be free from burrs
and damage. The parts with minor scores may be
reused after smoothing with emery cloth (#800 or finer).

Shaft
Oil seal sliding faces must be free from a step wear
which can be felt by the finger nail. Needle bearing fitting
face must be free from damage and wear.

O-ring, Oil Seal, Retaining Ring
Be sure to discard used parts, and always use new
parts for installation. Prior to installation, lubricate all
seals and rings with power steering fluid.

Pressure Switch
Check the switch operation as follows:
With engine idling and A/C on, turn the steering wheel
fully to the left; compressor should interrupt and engine
idle speed will increase. Shut off A/C and again turn
steering fully to the left; engine idle will increase. I
f
system fails to function properly, disconnect connector
at the pressure switch and repeat system check while
testing continuity across disconnected SW connector.

Reassembly
1. Install oil seal to front housing. Be sure to discard
used oil seal, and always use new parts fo
r
installation.
CAUTION: When installing the oil seal, be careful
not to damage the oil seal contacting surface of the
housing.
2. Install shaft assembly.
3. Install the vanes to roter with curved face in contact
with the inner wall of cam.
442RS005
4. Install rotor and vanes to cam.
5. Install pin to front housing.
6. Install two new O-rings to front housing. Be sure to
discard used O-ring.
7. Install side plate.
CAUTION: When installing side plate, be careful not
to damage its inner surface. Damaged side plate
may cause poor pump performance, pump seizure
or oil leakage.
8. Install pump cartridge assembly to front housing.
9. Install snap ring to shaft end.
10. Install rear housing with a new O-ring. Be sure to
discard used O-ring. Then install bolt and tighten it
to specified torque.
Torque: 22-26 N




m (2.2-2.7 kg




m/16-20 lb ft)
11. Install suction pipe with a new O-ring. Be sure to
discard used O-ring. Then install bolt and tighten it
to specified torque.
Torque: 7.8-12 N




m (0.8-1.2 kg




m/6-9 lb ft)
12. Install relief valve and spring.
13. Install connector with a new O-ring. Be sure to
discard used O-ring. Tighten the connector to
specified torque.
Torque: 49-69 N




m (5.0-7.0 kg




m/36-51 lb ft)
14. Install pressure switch assembly and tighten it to
specified torque.
Torque: 15-20 N




m (1.5-2.0 kg




m/11-14 lb ft)

3B-26 POWER-ASSISTED STEERING SYSTEM

Power Steering Pump and Associated Parts (6VE1)
RTW33BLF000701

Legend
(1) Pump Assembly
(2) Hose, Suction
(3) Hose, Flexible


(4) Bolt
(5) Connector, Pressure switch

Removal
1. Remove the drive belt.
2. Place a drain pan below the pump.
3. Disconnect the suction hose.
4. Disconnect the flexible hose.
5. Disconnect the oil pressure switch connector.
6. Remove the power steering fixing bolt and remove
the pump assembly.

Installation
1. Install the pump assembly to the pump braket,
tighten the fixing bolt to the specified torque.
Torque: 31-63 N·m (3.2-6.4 kg·m/23-46 lb ft)
2. Connector the oil pressure switch connector.
3. Install the flexible hose.
Tighten the eye bolt to specified torque.
Torque: 49 - 59 N·m (5.0 – 6.0 kg·m/36 - 43 lb ft)
4. Install the drive belt.
5. Connect the suction hose, then fill and bleed
system.
Refer to Bleeding the Power Steering System in this
section.

3B-28 POWER-ASSISTED STEERING SYSTEM

Inspection and Repair
Make all necessary adjustments, repairs, and part
replacements if wear, damage, or other problems are
discovered during inspection.

Rotor
442RS002
Check that the groove in the vane is free from excessive
wear and that the vane slides smoothly. When par
t
replacement becomes necessary, the pump cartridge
should be replaced as a subassembly.

Vane
442RS003
Sliding faces of the vane should be free from wear.
(Particularly the curved face at the tip that contact with
the cam should be free from wear and distortion). When
part replacement becomes necessary, the pump
cartridge should be replaced as a subassembly.

Cam
The inner face of the arm should have a uniform contact
pattern without a sign of step wear. When part
replacement becomes necessary, the pump cartridge
should be replaced as a subassembly.

Side Plate
The sliding faces of parts must be free from step wear
(more than 0.01 mm), which can be felt by the finge
r
nail.
The parts with minor scores may be reused after lapping
the face.

Relief Valve
The sliding face of the valve must be free from burrs
and damage. The parts with minor scores may be
reused after smoothing with emery cloth (#800 or finer).

Shaft
Oil seal sliding faces must be free from a step wear
which can be felt by the finger nail. Bushing fitting face
must be free from damage and wear.

O-ring, Oil Seal, Snap Ring
Be sure to discard used parts, and always use new
parts for installation. Prior to installation, lubricate all
seals and rings with power steering fluid.

Pressure Switch
Check the switch operation as follows:
With engine idling and A/C on, turn the steering wheel
fully to the left; compressor should interrupt and engine
idle speed will increase. Shut off A/C and again turn
steering fully to the left; engine idle will increase. I
f
system fails to function properly, disconnect connecto
r
at the pressure switch and repeat system check while
testing continuity across disconnected SW connector.

Reassembly
1. Install oil seal to front housing. Be sure to discard
used oil seal, and always use new parts fo
r
installation.
CAUTION: When installing the oil seal, be careful
not to damage the oil seal contacting surface of the
housing.
2. Install shaft assembly.

TRANSMISSION CONTROL SYSTEM (AW30–40LE) (V6 3.5L) 7A2-1
TRANSMISSION
TRANSMISSION CONTROL SYSTEM (AW30–40LE) (V6 3.5L)
CONTENTS

Service Precaution .................................................
7A2-2
General Description ...............................................
7A2-2
Electronic Control Diagram ...............................
7A2-3
Transmission Control Module (TCM) (1/2) ......
7A2-4
Transmission Control Module (TCM) (2/2) ......
7A2-5
TCM Point Table .................................................
7A2-6
TCM Voltage & Resistance Check Sheet .......
7A2-7
Control System Diagram ....................................
7A2-9
Control and Functions ........................................
7A2-10
Gear Shift Control 3rd start ...............................
7A2-10
Mode Type ...........................................................
7A2-10
Mode Selection ....................................................
7A2-10
Comparison of mode ..........................................
7A2-11
3rd start Mode .....................................................
7A2-11
Backup Mode .......................................................
7A2-11
Functions of Input / Output Components ........
7A2-12
CAN bus systems in automatic transmission
control (AW30-40LE) ........................................
7A2-13
High speed CAN bus ..........................................
7A2-13
Diagnosis .................................................................
7A2-13
Electronic Diagnosis ...........................................
7A2-13
Check Trans Indicator ........................................
7A2-13
On Board Diagnostic Check ..............................
7A2-13
"Check Trans" Check .........................................
7A2-14
Tech 2 OBD Connection ....................................
7A2-17
Snapshot Display With TIS2000 .................. 7A2-23
Service Programming System (SPS)............. 7A2-27
OBD Diagnostic Management System ............
7A2-30
16 - Terminal Data Link Connector (DLC) ......
7A2-31
Clear DTC ............................................................
7A2-32
DTC Check ..........................................................
7A2-32
TCM Precaution ..................................................
7A2-32
Information On TCM ...........................................
7A2-32
TCM Diagnostic Trouble Codes ........................
7A2-33
DTC P0560 (FLASHING CODE 25)
System Voltage Error ...........................................
7A2-34

DTC P0602 (FLASHING CODE 63)
Transmission Control Module (TCM)
Programming Error ................................................
7A2-36
DTC P0705 (FLASHING CODE 17)
Transmission Range Sensor Circuit
Malfunction .............................................................
7A2-38
DTC P0712 (FLASHING CODE 15)
Transmission Oil Temperature Sensor
Circuit Low Input ....................................................
7A2-42
DTC P0713 (FLASHING CODE 16)
Transmission Oil Temperature Sensor
Circuit Hight Input ..................................................
7A2-45
DTC P0717 (FLASHING CODE 14)
Input Speed Sensor Signal Error .........................
7A2-48
DTC P0722 (FLASHING CODE 11)
Output Speed Sensor Signal Error .....................
7A2-51
DTC P0743 (FLASHING CODE 33)
Torque Converter Clutch Electrical .....................
7A2-54
DTC P0748 (FLASHING CODE 35)
Pressure Control Solenoid Electrical ..................
7A2-57
DTC P0753 (FLASHING CODE 31)
Shift Solenoid S1 Electrical ..................................
7A2-60
DTC P0758 (FLASHING CODE 32)
Shift Solenoid S2 Electrical ..................................
7A2-63
DTC P1767 (FLASHING CODE 67)
ECM CAN Invalid ...................................................
7A2-66
DTC P1790 (FLASHING CODE 61)
Transmission Control Module ROM
Checksum Error .....................................................
7A2-69
DTC P1791 (FLASHING CODE 62)
Transmission Control Module RAM
Error .........................................................................
7A2-71
DTC U2104 (FLASHING CODE 65)
CAN BUSS OFF ....................................................
7A2-73

7A2-6 TRANSMISSION CONTROL SYSTEM (AW30 –40LE) (V6 3.5L)

TCM Point Table



RTW37ASF000101-1


PIN No. SIGNAL NAME
A1 GND
A2 PRESSURE CONTROL SOLENOID GND
A3 —
A4 PRESSURE CONTROL SOLENOID
A5 L-up SOLENOID
A6 STARTER SW(IG1)
A7 CAN COMMUNICATION (-)
A8 —
A9 —
A10 —
A11 T/M OIL TEMPERATURE SENSOR
A12 T/M OIL TEMPERATURE SENSOR GND
A13 —
A14 —
A15 SHIFT SOLENOID (S2)
A16 SHIFT SOLENOID (S1)
A17 CAN COMMUNICATION (+)
A18 —
A19 —
A20 —
A21 —
A22 —
A23 GND
A24 BATTERY

PIN No. SIGNAL NAME
B1 NEUTRAL START SW (R)
B2 POWER LAMP
B3 CHECK TRANS LAMP
B4 PATTERN SELECT SW (3rd START)
B5 SPEED SENSOR (+)
B6 INPUT REVOLUTION SENSOR (+)
B7 NEUTRAL START SW (D)
B8 NEUTRAL START SW (N)
B9 NEUTRAL START SW (3)
B10 3rd START LAMP
B11 OIL TEMPERATURE WARNING LAMP
B12 DIAGNOSIS TERMINAL
B13 PATTERN SELECT SW (POWER)
B14 SPEED SENSOR (-)
B15 —
B16 INPUT REVOLUTION SENSOR (+)
B17 —
B18 NEUTRAL START SW (L)
B19 NEUTRAL START SW (2)
B20 NEUTRAL START SW (P)
B21 TRANSMISFER LOW 4 SW
B22 BRAKE LAMP SW
B23 DIAGNOSIS OUT PUT
B24 —
B25 —
B26 CRUISE CONTROL UNIT