sensor ISUZU TROOPER 1998 Service Repair Manual

TRANSMISSION CONTROL SYSTEM (4L30±E)7A1±21
NOTE: To use the DTC again to identify a problem, you
will need to reproduce the fault or the problem. This may
require a new test drive or just turning the ignition on (this
depends on the nature of the fault).
1. IF you have a Tech2:
1. Connect the Tech2 if it is still not connected
GOTHROUGH Tech2 OBD II CONNECTION.
2. Push ªF4º and answer ªYesº to the question ªDo
you really want to clear the codes?º
a. When a malfunction remains as it is the Tech2
displays ª4L30E CODES NOT CLEAREDº. This
means that the problem is still there or that the
recovery was not done. Please GOTO DTC
CHECK.
b. When a malfunction has been repaired and the
recovery is done. The Tech2 displays ª4L30E
CODES CLEAREDº.
2. IF you have no Tech2:
To clear the DTC, remove Fuse ªStop, A/T CONTº
(C±14, 15A) for at least 10 seconds.
DTC Check
1. Diagnostic Trouble Codes (DTC) have been identified
by Tech2.
2. You have written the list of the DTCs. The order of the
malfunctions has no meanings for this PCM. Usually
only one or two malfunctions should be set for a given
problem.
3. Check directly the DTCs you identified. The DTCs are
sorted by number. Refer to Diagnostic Trouble Code
(DTC) Identification in this section.
PCM Precaution
The PCM can be damaged by:
1. Electrostatic discharge
2. The short circuit of some terminals to voltage or to
ground.
Electrostatic Discharge Damage Description:
1. Electronic components used to control systems are
often designed to carry very low voltage, and are very
susceptible to damage caused by electrostatic
discharge. It is possible for less than 100 volts of
static electricity to cause damage to some electronic
components. By comparison, it takes as much as
4,000 volts for a person to even feel the zap of a static
discharge.2. There are several ways for a person to become
statically charged. The most common methods of
charging are by friction and induction. An example of
charging by friction is a person sliding across a car
seat, in which a charge of as much as 25,000 volts
can build up. Charging by induction occurs when a
person with well insulated shoes stands near a highly
charged object and momentarily touches ground.
Charges for the same polarity are drained off, leaving
the person highly charged with the opposite polarity.
Static charges of either type can cause damage,
therefore, it is important to use care when handling
and testing electronic components.
NOTICE: To prevent possible electrostatic
discharge damage:
1. Do not touch the PCM connector pins or soldered
components on the PCM circuit board.
2. Be sure to follow the guidelines listed below if
servicing any of these electronic components:
3. Do not open the replacement part package until it is
time to install the part.
4. Avoid touching electrical terminals of the part.
5. Before removing the part from its package, ground
the package to a known good ground on the vehicle.
6. Always touch a known good ground before handling
the part. This step should be repeated before
installing the part if the part has been handled while
sliding across the seat, while sitting down from a
standing position or while walking some distance.
Information On PCM
1. The Powertrain Control Module (PCM) is located in
the center console and is the control center of the
electronic transmission control system.
2. The PCM must be maintained at a temperature below
185
F (85
C) at all times. This is most essential if the
vehicle is put through a paint baking process. The
PCM will become inoperative if its temperature
exceeds 85
C (185
F). Therefore, it is
recommended that the PCM be removed or that
temporary insulation be placed around the PCM
during the time the vehicle is in a paint oven or other
high temperature process.
3. The PCM is designed to process the various inputs
and then respond by sending the appropriate
electrical signals to control transmission upshift,
downshift, shift feel and torque converter clutch
engagement.
4. The PCM constantly interprets information from the
various sensors, and controls the systems that affect
transmission and vehicle performance. By analyzing
operational problems, the PCM is able to perform a
diagnostic function by displaying DTC(s) and aid the
technician in making repairs.
Intermittent Conditions
If the Tech2 displays a diagnostic trouble code as
intermittent, or if after a test drive a DTC does not
reappear though the detection conditions for this DTC are
present, the problem is most likely a faulty electrical

7A1±22
TRANSMISSION CONTROL SYSTEM (4L30±E)
connection or loose wiring. Terminals and grounds should
always be the prime suspect. Intermittents rarely occur
inside sophisticated electronic components such as the
PCM.
Use the DTC information to understand which wires and
sensors are involved.
When an intermittent problem is encountered, check
suspect circuits for:
1. Poor terminal to wire connection.
2. Terminals not fully seated in the connector body
(backed out).
3. Improperly formed or damaged terminals.
4. Loose, dirty, or corroded ground connections:
HINT: Any time you have an intermittent in more than
one circuit, check whether the circuits share a
common ground connection.
5. Pinched or damaged wires.
6. Electro±Magnetic Interference (EMI):
HINT: Check that all wires are properly routed away
from spark plug wires, distributor wires, coil, and
generator. Also check for improperly installed
electrical options, such as lights, 2±way radios, etc.Use the F3 SNAPSHOT mode of the Tech2 to help isolate
the cause of an intermittent fault. The snapshot mode will
record information before and after the problem occurs.
Set the snapshot to ªtriggerº on the suspect DTC. If you
notice the reported symptom during the test drive, trigger
the snapshot manually.
After the snapshot has been triggered, command the
Tech2 to play back the flow of data recorded from each of
the various sensors. Signs of an intermittent fault in a
sensor circuit are sudden unexplainable jump in data
values out of the normal range.
Transmission And PCM Identification
The chart below contains a list of all important information
concerning rear axle ratio, Powertrain Control Module
(PCM), and transmission identification.
VEHICLE
Rr axlePCMTRANSMISSION
TypeEngine
Rr axle
RatioISUZU Parts No.Calibration
CodeIsuzu Part No.Model Code
Isuzu /
Trooper3.2L V64.555
8±16254±949±0
8±16254±749±0
8±16253±989±0
G208±96018±272±3FP (4X4)

7A1±24
TRANSMISSION CONTROL SYSTEM (4L30±E)
Diagnostic Trouble Code (DTC)
Identification
DTC NUM-
BERDTC NAMEDTC TYPEªCHECK
TRANSº
P0218Transmission Fluid Over TemperatureD
P0560System Voltage MalfunctionCFlash
P0705Transmission Range Switch (Mode Switch) Illegal PositionD
P0706Transmission Range Switch (Mode Switch) PerformanceD
P0712Transmission Fluid Temperature Sensor Circuit Low Input
(TFT)D
P0713Transmission Fluid Temperature (TFT) Sensor Circuit High
InputD
P0719TCC Brake Switch Circuit High (Stuck ON)D
P0722Transmission Output Speed Sensor (OSS) Low InputCFlash
P0723Transmission Output Speed Sensor (OSS) IntermittentCFlash
P0730Transmission Incorrect Gear Ratio FlashCFlash
P0748Pressure Control Solenoid (PCS) (FORCE MOTOR) Circuit
ElectricalCFlash
P0753Shift Solenoid A ElectricalCFlash
P0758Shift Solenoid B ElectricalCFlash
P1790ROM Transmission Side Bad Check SumCFlash
P1792EEPROM Transmission Side Bad Check SumCFlash
P1835Kickdown Switch Always OND
P1850Brake Band Apply Solenoid MalfunctionD
P1860TCC Solenoid ElectricalD
DTC TYPEDEFINITION
CFlashing Check Trans on 1st failure
DNo lamps
NOTE: On the following charts, refer to the Powertrain
Control Module (PCM) section for the Wiring System, and
the Body and Accessories section for circuit diagram
details, parts location, and connector configuration.

TRANSMISSION CONTROL SYSTEM (4L30±E)7A1±25
DTC P0218 Transmission Fluid Over Temperature
D07RW029
Circuit Description
The Transmission Fluid Temperature (TFT) sensor is a
thermister that controls the signal voltage to the PCM.
The PCM supplies a 5±volt reference to the sensor on
circuit RED/BLK±GRN/RED. When the transmission fluid
is cold, the sensor resistance is high and the PCM will
sense high signal voltage. As the fluid temperature
warms to a normal transmission operating temperature of
100
C (212
F), the sensor resistance becomes less and
the voltage decreases to 1.5 to 2.0 volts.
This DTC detects a high transmission temperature for a
long period of time. This is a type ªDº DTC.
Conditions For Setting The DTC

No TFT DTCs P0712 or P0713.

TFT is greater than 135
C (275
F).

All conditions met for 21 seconds.
Action Taken When The DTC Sets

Hot mode TCC Shift Pattern.

The PCM will not illuminate the CHECK TRANS
Lamp.

ATF Lamp ON. (TFT is greater than 145
C (293
F).)

Disable E±side TCC OFF request.
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 warm±up 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 16±way 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.

Check harness routing for a potential short to ground
in circuit RED/BLK±GRN/RED.

Scan tool TFT sensor temperature should rise
steadily to about 100
C (212
F), then stabilize.

Check for a ªskewedº (mis±scaled) sensor by
comparing the TFT sensor temperature to the
ambient temperature after a vehicle cold soak. A
ªskewedº sensor can cause delayed garage shifts or
TCC complaints.

Check for a possible torque converter stator problem.

Verify customer driving habits, trailer towing, etc.
Test Description
The numbers below refer to the step numbers on the
diagnostic chart.
3. This test checks for a ªskewedº sensor or shorted
circuit.
4. This test simulates a TFT DTC P0713.

7A1±26
TRANSMISSION CONTROL SYSTEM (4L30±E)
DTC P0218 Transmission Fluid Over Temperature
StepActionYe sNo
1Perform the following checks:

Check for possible engine system problems.

Transmission fluid checking procedure. Refer to Checking
Transmission Fluid Level and Condition in Automatic
Transmission (4L30±E) Section.
Were the checks performed?
Go to Step 2Ð
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 ªClear Infoº
function is used.
3. Record the DTC ªFailure Recordsº.
Is the TFT sensor signal voltage less than 0.33 volts?
Go to Step 3
Go to Diagnostic
Aids
31. Turn the ignition ªoffº.
2. Disconnect the transmission 16±way connector H±53
(additional DTCs may set).
Is the TFT sensor signal voltage greater than 4.92 volts?
Go to Internal
Wiring Harness
Check.
Go to Step 4
4Inspect/repair circuit RED/BLK±GRN/RED for a short to ground.
Was a problem found?
Go to Step 6Go to Step 5
51. Inspect the PCM for poor connections.
2. Replace the PCM if no poor connections were found.
Is the replacement complete?
Go to Step 6Ð
61. After the repair is complete, use the scan tool to select ªDTCº,
then ªClear Infoº function and ensure the following conditions
are met:
TFT is less than 125
C (257
F) for at least 10 seconds.
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

7A1±36
TRANSMISSION CONTROL SYSTEM (4L30±E)
DTC P0712 Transmission Fluid Temperature (TFT) Sensor Circuit Low Input
D07RW029
Circuit Description
The TFT sensor is a thermister that controls the signal
voltage to the PCM. The PCM supplies a 5±volt reference
signal to the sensor on circuit RED/BLK±GRN/RED.
When the transmission fluid is cold, the sensor resistance
is high. The PCM detects high signal voltage. As the
transmission fluid temperature increases to the normal
operating temperature of 100
C (212
F), the sensor
resistance becomes less and the voltage decreases to
1.5 to 2 volts. With transmission fluid over temperature
and DTC P0218 also set, check the transmission cooling
system.
This DTC detects a continuous short to ground in the TFT
signal circuit or the TFT sensor. This is a type ªDº DTC.
Conditions For Setting The DTC

Battery voltage is between 10 and 16 volts.

Ignition is ªonº.

TFT sensor indicating a voltage less than 0.4 volts.

All conditions met for 20 seconds.
Action Taken When The DTC Sets

Transmission default temperature will be:
80
C (176
F) if engine temperature code is set.
100
C (212
F) if engine temperature is warm.
80
C (176
F) if engine run time is greater than 5
minutes.
21
C (69.8
F) if engine run time is less than 5
minutes.

The PCM will not illuminate the CHECK TRANS
Lamp.
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.
Diagnostic Aids

Check harness routing for a potential short to ground
in circuit RED/BLK±GRN/RED. Scan tool TFT
display should rise steadily to about 100
C (212
F),
then stabilize.

Inspect the wiring for poor electrical connection at the
PCM and at the transmission 16±way 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.

The temperature to resistance value scale may be
used to test the TFT sensor at the various
temperature levels to evaluate the possibility of a
ªskewedº (mis±scaled) sensor.
A ªskewedº sensor could result in delayed garage
shifts or TCC complaints.

Verify customer driving habits, trailer towing, etc.
Test Description
The numbers below refer to the step numbers on the
diagnostic chart:
3. This test checks for a short to ground or a ªskewedº
sensor.
4. This test checks for an internal fault within the
transmission by creating an open.

TRANSMISSION CONTROL SYSTEM (4L30±E)7A1±37
Resistance Chart

C

FResistance (k
)
±40±40672
03265
206825
801762.5
1202480.78
1503040.37
DTC P0712 Transmission Fluid Temperature (TFT) Sensor Circuit Low Input
StepActionYe sNo
1Perform the transmission fluid checking procedure. Refer to
Checking Transmission Fluid Level and Condition in Automatic
Transmission (4L30±E) section.
Was the fluid checking procedure performed?
Go to Step 2
Refer to
Checking
Transmission
Fluid Level and
Condition in
Automatic
Transmission
(4L30±E) 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 ªFreeze
Frameº and ªFailure Recordsº for reference, as data will be lost
when the ªClear Infoº function is used.
3. Record the DTC ªFreeze Frameº and ªFailure Recordsº.
Does the scan tool display a TFT sensor signal voltage less than
0.4 volts?
Go to Step 3
Go to Diagnostic
Aids
31. Turn the ignition ªoffº.
2. Disconnect the transmission 16±way connector H±53.
3. Turn the ignition ªonº.
Does the TFT signal voltage change to match the voltage 4.92
volts?
Go to Step 4Go to Step 9
4Using the J39200 DVOM, measure the resistance between
terminals 3(C) and 5 (D).
Is the resistance within specifications? (See Resistance Chart.)
Go to Diagnostic
Aids
Go to Step 5
51. Disconnect the transmission 5±way connector M±6.
2. Using the J39200 DVOM, measure the resistance between
terminals 3(C) and 5(D).
Is the resistance within specifications? (See Resistance Chart.)
Go to Diagnostic
Aids
Go to Step 6
61. Remove the transmission oil pan. Refer to Transmission Oil
Temperature Sensor (Adapter Case) in Automatic
Transmission (4L30±E) section.
2. Check the internal wiring harness for a short to ground.
Was a problem found?
Go to Step 8Go to Step 7
71. Disconnect the internal wiring harness at the TFT sensor.
2. Measure the resistance of the TFT sensor.
Is the resistance within specifications? (See Resistance Chart.)
Go to Diagnostic
Aids
Go to Step 8
8Replace the TFT Sensor.
Is the replacement complete?
Go to Step 12Ð

7A1±38
TRANSMISSION CONTROL SYSTEM (4L30±E)
DTC P0712 Transmission Fluid Temperature (TFT) Sensor Circuit Low Input (Cont'd)
StepNo Ye s Action
9Check circuit RED/BLK±GRN/RED for a short to ground.
Was a problem found?
Go to Step 12Go to Step 10
10Check the PCM for faulty connections.
Was a problem found?
Go to Step 12Go to Step 11
11Replace the PCM. Refer to Powertrain Control Module (PCM) in
Automatic Transmission (4L30±E) section.
Is the replacement complete?
Go to Step 12Ð
121. After the repair is complete, use the scan tool to select ªDTCº,
then ªClear Infoº function and ensure the following conditions
are met:
TFT sensor indicates a voltage greater than 0.33 volts for 2
seconds.
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±39
DTC P0713 Transmission Fluid Temperature (TFT) Sensor Circuit High Input
D07RW029
Circuit Description
The TFT sensor is a thermistor that controls the signal
voltage to the PCM. The PCM supplies a 5±volt reference
signal to the sensor on circuit RED/BLK±GRN/RED.
When the transmission fluid is cold, the sensor resistance
is high and the PCM will sense high signal voltage. As the
transmission fluid temperature warms to the normal
operating temperature of 100
C (212
F), the sensor
resistance becomes less and the voltage decreases to
about 1.5 to 2 volts.
This DTC detects a continuous open or short to power in
the TFT signal circuit or the TFT sensor. This is a type ªDº
DTC.
Conditions For Setting The DTC

Battery voltage is between 10 and 16 volts.

Ignition is ªonº.

TFT sensor indicating a voltage greater than 4.86
volts.

All conditions met for 20 seconds.
Action Taken When The DTC Sets

Transmission default temperature will be:
80
C (176
F) if engine temperature code is set.
100
C (212
F) if engine temperature is warm.
80
C (176
F) if engine run time is greater than 5
minutes.
21
C (69.8
F) if engine run time is less than 5
minutes.

The PCM will not illuminate the CHECK TRANS
Lamp.
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.
Diagnostic Aids

Inspect the wiring for poor electrical connection at the
PCM and at the transmission 16±way 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.

Scan tool displays transmission fluid temperature in
degrees. After transmission is operating, the
temperature should rise steadily to about 100
C
(212
F), then stabilize.

The temperature to resistance value scale may be
used to check the TFT sensor at the various
temperature levels to evaluate the possibility of a
ªskewedº (mis±scaled) sensor.
A ªskewedº sensor could result in hard shifts or TCC
complaints.
Test Description
The numbers below refer to the step numbers on the
diagnostic chart:
3. This check verifies problem in the TFT sensor circuit.
4. This test simulates a TFT sensor DTC P0712. If the
PCM recognizes the low signal voltage (high
temperature), and the scan tool displays 146
C
(295
F) or greater, the PCM and wiring are OK.

7A1±40
TRANSMISSION CONTROL SYSTEM (4L30±E)
5. This test checks the TFT sensor and internal wiring
harness.
Resistance Chart

C

FResistance (k
)
±40±40672
03265
206825
801762.5
1202480.78
1503040.37
DTC P0713 Transmission Fluid Temperature (TFT) Sensor Circuit High Input
StepActionYe sNo
1Perform the transmission fluid checking procedure.
Refer to Checking Transmission Fluid Level and Condition in
Automatic Transmission (4L30±E) section.
Was the fluid checking procedure performed?
Go to Step 2
Refer to
Checking
Transmission
Fluid Level and
Condition in
Automatic
Transmission
(4L30±E) 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 ªFreeze Frameº and ªFailure Recordsº.
Does the scan tool display a TFT sensor signal voltage greater
than 4.86 volts?
Go to Step 3
Go to Diagnostic
Aids
31. Turn the ignition ªoffº.
2. Disconnect the transmission 16±way connector H±53.
3. Install a fused jumper wire from terminal 3(C) to 5(D) on the
engine harness.
4. Turn the ignition ªonº.
Does the TFT signal voltage drop to less than 0.4 volts?
Go to Step 4Go to Step 9
41. Turn the ignition ªoffº.
2. Using the J39200 DVOM, measure the resistance between
terminals 3(C) and 5(D).
Is the resistance within specifications? (See Resistance Chart.)
Go to Diagnostic
Aids
Go to Step 5
51. Disconnect the transmission 5±way connector M±6.
2. Using the J39200 DVOM, measure the resistance between
terminals 3(C) and 5(D).
Is the resistance within specifications? (See Resistance Chart.)
Go to Diagnostic
Aids
Go to Step 6
61. Remove the transmission oil pan.
2. Check the internal wiring harness for an open. Refer to
Transmission Oil Temperature Sensor (Adapter Case) in
Automatic Transmission (4L30±E) section.
Was a problem found and corrected?
Go to Step 13Go to Step 7
71. Disconnect the internal wiring harness at the TFT sensor.
2. Measure the resistance of the TFT sensor.
Is the resistance within specifications? (See Resistance Chart.)
Go to Diagnostic
Aids
Go to Step 8