2002 ISUZU AXIOM low oil pressure

7A1±10
TRANSMISSION CONTROL SYSTEM (4L30±E)
Functions of Input / Output Components
ComponentsFunction
Speed sensor
(fixed to transmission)Senses rotation of output shaft and feeds the data to Powertrain Control Module
(PCM).
Throttle position sensor
(TPS)
(fixed to engine)Senses the extent of throttle valve opening and the speed of the throttle valve
lever motion to open the valve. Feeds the data to PCM.
I
N
Brake switch
(fixed to brake pedal)Senses whether the driver has pressed the brake pedal or not and feeds the
information to PCM.
N
P
UMode switch (fixed to
transmission)Senses the select lever position, and feeds the information to PCM.
U
T

S
Power drive switch
(fixed to front console)Senses whether the driver has selected the power mode, and feeds the
information to PCM.
S
IT/M oil temperature sensorSenses the T/M oil temperature and feeds the data to PCMI
G
N
A
Engine coolant
temperature sensorSenses the engine coolant temperature, and feeds the data to PCM.
A
LEngine speed signalFeeds the signals monitoring engine speed to PCM from crank angle sensor.L
Air conditioning informationSenses whether the air conditioner has been switched on or not, and feeds the
information to PCM.
Winter switch (fixed to front
console)Senses whether the driver has selected the winter mode, and feeds the
information to PCM.
Cruise controller
(Overdrive OFF signal)Downshift takes place when overdrive OFF signal is received from auto cruise
controller integrated in PCM.
O
U
T
S
Shift solenoid A, BSelects shift point and gear position suited to the vehicle running condition on
the basis of PCM output.
P
U
TS
O
L
E
Band apply solenoidControls oil flow suited to the vehicle running condition on the basis of PCM
output.

S
I
G
E
N
O
I
Torque Converter
Clutch PWM solenoidControls clutch apply suited to the vehicle running condition on the basis of PCM
output.
G
N
A
LI
DForce motor
(Pressure regulator
valve)Adjusts the oil pump delivery pressure to line pressure suited to the vehicle
running condition on the basis of PCM output.

7A1±16
TRANSMISSION CONTROL SYSTEM (4L30±E)
060R200033
Once the test vehicle has been identified an ªApplication
(Powertrain) Menuº screen appears. Please select the
appropriate application.
The following table shows, which functions are used for
the available equipment versions.
F0: Diagnostic Trouble Codes
F0: Read DTC Info Ordered By Priority
F1: Clear DTC Information
F2: DTC Information
F1: Data Display
F0: Transmission Data
F2: Snap Shot
F3: Actuator Tests
F0: Lamps
F0: Check Light
F1: Winter Drive Lamp
F2: Power Drive Lamp
F3: AT Oil Temperature Lamp
F1: Solenoids
F0: Solenoid 1-2/3-4 Test
F1: Solenoid 2-3 Test
F2: TCC Solenoid
F3: Band Apply Solenoid
F4: Pressure Control Solenoid (PCS)
F4: Function Tests
F0: Reset Oil Life Monitor

TRANSMISSION CONTROL SYSTEM (4L30±E)7A1±17
Diagnostic Trouble Codes
The purpose of the ªDiagnostic Trouble Codesº mode is to
display stored PCM trouble codes.
When ªDiagnostic Trouble Codesº is selected an
ªApplication Menuº screen appears.
Clear DTC Information
The purpose of the ªClear DTC Informationº mode is to
command the clearing of stored PCM trouble codes.
When ªClear DTC Informationº is selected, a ªClear DTC
Informationº, warning screen appears. This screen
informs you that by cleaning DTC's, ªall stored DTC
information in controller will be erasedº.
Do you want to clear DTC's (Yes/No).
Press either the Yes or No key when answering.
After clearing codes, confirm system operation by test
driving the vehicle.
Allow the vehicle to shift through all four forward gears in a
manner which attempts to repeat the failure condition.
NOTE: When the trouble has not been repaired and the
trouble code cannot be erased, check the vehicle again.
DTC Information
When ªDTC Informationº is selected, an ªApplication
Menuº appears with a list of DTC information function
keys addressing DTC specifics and their origins.
Function key selections may vary for particular vehicle
and/or system.
Data Display
The purpose of the ªData Displayº mode is to
continuously monitor data parameters.
The current actual values of all important sensors and
signals in the system are display through F1 mode.
When ªData Displayº is selected an ªApplication Menuº
appears. Please select either ªEngineº or ªTransmission
Data Displayº.
See ªTransmission Dataº on next page.
Snapshot
When ªSnapshotº is selected an ªApplication Menuº
appears.
When ªTransmission Snapshotº application is selected
from the ªApplication Menuº, a ªSnapshot Menuº
appears, displaying several options. ªSnapshotº options
may vary from one system to another.
ªSnapshotº allows a recording of all vehicle parameters.
There parameters may then be replayed at a future point
in time.
This action allows you to focus on making the condition
occur, rather than trying to view all of the data in
anticipation of the fault. The snapshot will collect
parameter information around a trigger point that you
select.
When a snapshot is taken. It is recorded onto the
PCMCIA memory card. When the Tech 2 is powered
down. Snapshots are not lost.
Actuator Tests
The purpose of ªActuator Testsº mode is to check for
correct operation of electronic system actuators.Lamps
You can operate the lamps by pressing the ON and OFF
buttons.
Preconditions: none
Solenoid
Solenoid 1-2/3-4, Solenoid 2-3, TCC Solenoid
You can operate the solenoids by pressing the ON and
OFF buttons.
Preconditions: P±N position, no vehicle speed, no engine
speed
Band Apply Solenoid
You can operate the solenoid by pressing the ON and
OFF buttons.
Preconditions: P-N position, idle engine speed, no vehicle
speed.
Pressure Control Solenoid (PCS)
You can set desired PCS Current using the ªIncrementº
(+25) and ªDecrementº (±25) button. The PC Solenoid
Data informs about PCS Current, Pressure and Duty
Cycle.
Preconditions: P±N position, no engine speed, no vehicle
speed
Reset Oil Life Monitor
Displays parameter ªOil Life Monitorº and resets to 100%
if Yes-button is pressed on Reset-question. ªNoº leaves
test.
Preconditions: no vehicle speed, no engine speed
NOTE:
Freeze Frame (Powertrain DTC A/B Type)
Freeze Frame is an element of the Diagnostic Manage-
ment System which stores various vehicle information at
the moment an emissions-related fault is stored in
memory and when the MIL is commanded on. These data
can help to identify the cause of a fault. Refer to
Storing
And Erasing Freeze Frame Data
for more detailed in-
formation.
Failure Records (Powertrain DTC C/D Type)
Failure Records data is an enhancement of the OBD II
Freeze Frame feature. Failure Records store the same
vehicle information as does Freeze Frame, but it will store
that information for any fault which is stored in on-board
memory, while Freeze Frame stores information only for
emission-related faults that command the MIL on.

7A1±56
TRANSMISSION CONTROL SYSTEM (4L30±E)
DTC P0742 Torque Converter Clutch (TCC) System Stuck On
D07R200008
Circuit Description
The PCM energizes the TCC solenoid by creating an
ignition voltage on circuit BRN/BLU. When ignition
voltage is energized by the PCM, the TCC solenoid stops
converter signal oil from exhausting. This causes
converter signal oil pressure to increase and move the
TCC valve. The TCC solenoid will deenergize when the
PCM no longer provides ignition voltage. When the TCC
solenoid is deenergized, it will exhaust fluid and release
the TCC.
This DTC detects low torque converter slip when the TCC
is commanded ªoffº. This is a type ªBº DTC.
Conditions For Setting The DTC
The following conditions occur once per TCC cycle, three
consecutive times:

No TPS DTCs P0122 or P0123.

No OSS DTCs P0722 or P0723.

No TCC solenoid DTC P1860.

TP angle is greater than 20%.

Engine speed is greater than 500 rpm and less than
3,000 rpm.

Engine vacuum is between 0 and 70 kPa.

Commanded gear is not 1st.

Gear range is D4.

TCC is commanded ªoffº.

No TCC Stuck off DTC P1870.
TCC slip speed is between ±20 and 40 rpm for 2
seconds.

Vehicle speed is greater than 25 km/h (15 mph) and
less than 120 km/h (75 mph).

Speed ratio is greater than 0.9 and less than 2.0.
Action Taken When The DTC Sets

For lamp illuminate refer to DTC type definition (type
B).

Inhibit TCC engagement.
Conditions For Clearing The MIL/DTC

The PCM will turn off the MIL and CHECK TRANS
Lamp after three consecutive ignition cycles without a
failure reported.

The DTC can be cleared from the PCM history by
using a scan tool.

The DTC will be cleared from history when the vehicle
has achieved 40 warmup cycles without a failure
reported.

The PCM will cancel the DTC default actions when
the fault no longer exists and the ignition is cycled ªoffº
long enough to power down the PCM.

TRANSMISSION CONTROL SYSTEM (4L30±E)7A1±59
DTC P0748 Pressure Control Solenoid (PCS) (Force Motor) Circuit Electrical
StepActionYe sNo
1Were you sent here from the ªPowertrain On±Board Diagnostic
(OBD) System Checkº?
Go to Step 2
Go to OBD
System Check
Refer to
Driveability and
Emission in
Engine section
21. Install the scan tool.
2. With the engine ªoffº, turn the ignition switch ªonº.
NOTE: Before clearing DTC(s), use the scan tool to record ªFailure
Recordsº for reference, as data will be lost when the ªClear Infoº
function is used.
3. Record the DTC ªFailure Recordsº.
4. While the engine is operating, put the transmission in Park.
5. Using the scan tool, apply 70 through 1060 milliampere (mA)
while observing ªPC Ref. Currentº and ªPC Act. Currentº.
Is the ªPC Act. Currentº reading always within 160 mA?
Go to Diagnostic
Aids
Go to Step 3
31. Turn the ignition ªoffº.
2. Disconnect the transmission 4±way connector E±40.
3. Using the J39200 DVOM, measure the resistance between
terminals E40±2(B) and E40±4(C).
Is the resistance within 3±7 ohms?
Go to Step 7Go to Step 4
41. Remove the transmission oil pan. Refer to Solenoid (Adapter
Case Valve Body) in Automatic Transmission (4L30±E)
section.
2. Disconnect the internal wiring harness at the PCS.
3. Measure the resistance of the PCS.
Is the resistance within 3±7 ohms?
Go to Step 6Go to Step 5
5Replace the PCS.
Is the replacement complete?
Go to Step 10Ð
6Repair the internal wiring harness for an open.
Is the repair complete?
Go to Step 10Ð
7Inspect/repair circuits VIO/WHT and VIO/RED.
Was a problem found?
Go to Step 10Go to Step 8
8Inspect/repair circuits VIO/WHT and VIO/RED for a short to
ground or poor connections.
Was a problem found?
Go to Step 10Go to Step 9
9Replace the PCM. Refer to Powertrain Control Module (PCM) in
Automatic Transmission (4L30±E) section.
Is the replacement complete?Go to Step 10Ð
101. After the repair is complete, use the scan tool to select ªDTCº,
then ªClear Infoº function and ensure the following conditions
are met:
The PCS duty cycle is not at its electrical high or low limit.
2. Review the scan tool ªDTC Infoº.
Has the last test failed or is the current DTC displayed?
Begin diagnosis
again
Go to
Step 1
Repair verified
Exit DTC table

TRANSMISSION CONTROL SYSTEM (4L30±E)7A1±75
DTC P1850 Brake Band Apply Solenoid Malfunction
D07R200010
Circuit Description

The brake band apply solenoid is a normally open
solenoid which controls the flow of fluid for brake band
application. The Powertrain Control Module (PCM)
uses Pulse Width Modulation (PWM) and changes
the duty cycle to control the solenoid. The PCM turns
the solenoid on (energized) and off (deenergized) at a
constant frequency. The length of time the solenoid is
energized during each on/off cycle is called the pulse
width. By varying or ªmodulatingº the pulse width, the
solenoid output pressure is changed. Since the
solenoid is normally open, increasing the pulse width
increases the duty cycle and decreases the output
pressure. PWM control provides smooth band
application without an accumulator. The band is only
applied in first and second gears.

In the event of an electrical failure (open), the
solenoid regulates at the maximum oil flow (0% duty
cycle).

The solenoid is activated by a current. This current is
produced by applying a voltage to one side (the High
side) and a ground to the other side (Low side).

The High Side Driver (HSD) is a circuit of the PCM
that acts as a switch between the solenoids and the
supply voltage. The High side of the solenoid is
permanently supplied with voltage. When the ignition
is off, the HSD is turned off.This DTC detects a continuous open or short to ground in
the brake band apply solenoid circuit or the brake band
apply solenoid. This is a type ªDº DTC.
Conditions For Setting The DTC

Battery voltage is between 10 and 16 volts.

Ignition is ªonº, Engine ªrunº.

The PCM commands the solenoid ªonº and the
voltage remains high (B+), or the PCM commands
the solenoid ªoffº and the voltage remains low (zero
volts).

All conditions met in 1.34 ~ 1.56 seconds.
Action Taken When The DTC Sets

Inhibit brake band apply solenoid.

The PCM will not illuminate the Malfunction Indicator
Lamp (MIL).
Conditions For Clearing The DTC

The DTC can be cleared from the PCM history by
using a scan tool.

The DTC will be cleared from history when the vehicle
has achieved 40 warmup cycles without a failure
reported.

The PCM will cancel the DTC default actions when
the fault no longer exists and the ignition is cycled ªoffº
long enough to power down the PCM.

TRANSMISSION CONTROL SYSTEM (4L30±E)7A1±79
DTC P1860 TCC PWM Solenoid Electrical
D07R200011
Circuit Description
The PCM allows current to flow through the solenoid coil
according to the duty cycle (percentage of ªonº and ªoffº
time). This current flow through the solenoid coil creates
a magnetic field that magnetizes the solid core. The
magnetized core attracts the check ball to seat against
spring pressure. This blocks the exhaust for the TCC
signal fluid and allows 2±3 drive fluid to feed to TCC signal
circuit.The TCC signal fluid pressure acts on the TCC
regulator valve to regulate line pressure and to apply fluid
pressure to the torque converter clutch shift control valve.
When the TCC shift valve is in the apply position,
regulated apply fluid pressure is directed through the TCC
valve to apply the torque converter clutch. The TCC
PWM solenoid is used in conjunction with the TCC PWM
solenoid to regulate fluid to the torque converter. The
TCC PWM solenoid is attached to the valve body within
the transmission.
This DTC detects a continuous open or short to ground or
ignition in the TCC circuit or the TCC PWM solenoid. This
is a type ªBº DTC.
Conditions For Setting The DTC

Battery voltage is between 10 and 16 volts.

No shift solenoid A DTCs P0751 or P0752 or P0753.

No shift solenoid B DTCs P0756 or P0757 or P0758.

Ignition is ªonº, Engine ªrunº.

The PCM commands the solenoid ªonº and the
voltage remains low (zero volts).

The PCM commands the solenoid ªoffº and the
voltage remains high (B+).

All conditions met for 0.875 ~ 1.25 seconds.
Action Taken When The DTC Sets

Inhibit TCC engagement.
For lamp illuminate refer to
DTC type definition (type
B).
Conditions For Clearing The MIL/DTC

The PCM will turn off the MIL and CHECK TRANS
Lamp after three consecutive ignition cycles without a
failure reported.

The DTC can be cleared from the PCM history by
using a scan tool.

The DTC will be cleared from history when the vehicle
has achieved 40 warmup cycles without a failure
reported.

The PCM will cancel the DTC default actions when
the fault no longer exists and the ignition is cycled ªoffº
long enough to power down the PCM.
Diagnostic Aids

Inspect the wiring for poor electrical connections at
the PCM and at the transmission connector. Look for
possible bent, backed out, deformed or damaged
terminals. Check for weak terminal tension as well.
Also check for a chafed wire that could short to bare
metal or other wiring. Inspect for a broken wire inside
the insulation.

When diagnosing for a possible intermittent short or
open condition, move the wiring harness while
observing test equipment for a change.
Test Description
The numbers below refer to the step numbers on the
diagnostic chart
:
3. This test checks for voltage to the solenoid.
4. This test checks the ability of the PCM and wiring to
control the ignition circuit.
9. This test checks the resistance of the TCC solenoid
and the internal wiring harness.

8A±22LIGHTING SYSTEM
Light NameBulb No.Rated
PowerNumber of
BulbsLens ColorRemarks
Headlight9005/900660w/51w2WhiteHalogen
Front Turn signal Light/
Front Side Marker Light/Parking Light1157NA27w/8w2Amber
Rear Turn Signal Light744021w2Amber
Backup Light92118w2White
Taillight/Stoplight744321w/5w2Red
High Mounted Stoplight92118w2Red
License Plate Light (Tailgate type)1685w2White
Map LightÐ8w2White
Dome LightÐ10w1White
Luggage Room LightÐ5w1White
Courtesy LightÐ3.4w4White
Check TransÐ1.4w1RedMeter
A/T Oil TempÐ1.4w1RedMeter
Cruise SetÐ1.4w1GreenMeter
Power DriveÐ1.4w1AmberMeter
Winter DriveÐ1.4w1GreenMeter
Turn SignalÐ1.4w2GreenMeter
Check TODÐ1.4w1RedMeter
High BeamÐ1.4w1BlueMeter
ABSÐ1.4w1AmberMeter
Seat BeltÐ2w1RedMeter
Indicator/Warning
Malfunction Indicator
(Check Engine)Ð1.4w1AmberMeter
Indicator/Warning
LightLow FuelÐ1.4w1AmberMeterg
Reduced PowerÐ1.4w1AmberMeter
Sports ModeÐ1.4w1GreenMeter
TOD FrontÐ1.1w1GreenMeter
TOD AutoÐ1.1w1GreenMeter
TOD RearÐ1.1w1GreenMeter
Oil PressureÐ1.4w1RedMeter
Brake SystemÐ1.4w1RedMeter
ChargeÐ1.4w1RedMeter
A/T Shift PositionÐ1.1w7
P,N,D,3,2,L
:Green
R: Amber
Meter
Air BagÐ2w1RedMeter
Illumination LightMeterÐ3.4w4Meter
Shift leverÐ1.4w1WhiteShift lever
Vanity MirrorÐ2w2WhiteSun Visor
Cigarette LighterÐ1.4w1WhiteCigarette
Lighter
AshtrayÐ1.4w1WhiteAshtray