1998 ISUZU TROOPER check transmission fluid

TRANSMISSION CONTROL SYSTEM (4L30±E)7A1±1
TRANSMISSION
TRANSMISSION CONTROL SYSTEM (4L30±E)
CONTENTS
Service Precaution 7A1±2. . . . . . . . . . . . . . . . . . . . . .
General Description 7A1±2. . . . . . . . . . . . . . . . . . . . .
Shift Control 7A1±6. . . . . . . . . . . . . . . . . . . . . . . . . .
Band Apply Control 7A1±6. . . . . . . . . . . . . . . . . . . .
Torque Converter Clutch Control 7A1±6. . . . . . . . .
Line Pressure Control 7A1±6. . . . . . . . . . . . . . . . . .
On±Board Diagnostic System 7A1±6. . . . . . . . . . .
Fail Safe Mechanism 7A1±6. . . . . . . . . . . . . . . . . . .
Torque Management Control 7A1±6. . . . . . . . . . . .
ATF Warning Control 7A1±6. . . . . . . . . . . . . . . . . . .
ABS Control (If equipped) 7A1±6. . . . . . . . . . . . . .
Winter Drive Mode 7A1±9. . . . . . . . . . . . . . . . . . . . .
Backup Mode 7A1±9. . . . . . . . . . . . . . . . . . . . . . . . .
Functions of Input / Output Components 7A1±10. .
Diagnosis 7A1±11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Check Trans Indicator 7A1±11. . . . . . . . . . . . . . . . . .
Diagnostic Check 7A1±11. . . . . . . . . . . . . . . . . . . . . .
ªCheck Transº Check 7A1±12. . . . . . . . . . . . . . . . . .
Tech2 OBD II Connection 7A1±13. . . . . . . . . . . . . . .
OBD II Diagnostic Management System 7A1±18. .
16 ± Terminal Data Link Connector (DLC) 7A1±19.
Malfunction Indicator Lamp (MIL) 7A1±20. . . . . . . .
Types Of Diagnostic Trouble Codes
(DTCs) 7A1±20. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Clear DTC 7A1±20. . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC Check 7A1±21. . . . . . . . . . . . . . . . . . . . . . . . . . .
PCM Precaution 7A1±21. . . . . . . . . . . . . . . . . . . . . . .
Information On PCM 7A1±21. . . . . . . . . . . . . . . . . . .
Intermittent Conditions 7A1±21. . . . . . . . . . . . . . . . .
Transmission And PCM Identification 7A1±22. . . . .
Diagnostic Trouble Code (DTC)
Identification 7A1±24. . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0218 Transmission Fluid Over
Temperature 7A1±25. . . . . . . . . . . . . . . . . . . . . . . . . . . Conditions For Setting The DTC 7A1±25. . . . . . . . .
Action Taken When The DTC Sets 7A1±25. . . . . . .
Conditions For Clearing The DTC 7A1±25. . . . . . . .
Diagnostic Aids 7A1±25. . . . . . . . . . . . . . . . . . . . . . . .
Test Description 7A1±25. . . . . . . . . . . . . . . . . . . . . . .
DTC P0560 System Voltage Malfunction 7A1±27. . .
DTC P0705 Transmission Range Switch
(Mode Switch) Illegal Position 7A1±30. . . . . . . . . . . .
DTC P0706 Transmission Range Switch
(Mode Switch) Performance 7A1±33. . . . . . . . . . . . . .
DTC P0712 Transmission Fluid Temperature
(TFT) Sensor Circuit Low Input 7A1±36. . . . . . . . . . .
DTC P0713 Transmission Fluid Temperature
(TFT) Sensor Circuit High Input 7A1±39. . . . . . . . . . .
DTC P0719 TCC Brake Switch Circuit High
(Stuck On) 7A1±42. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0722 Transmission Output Speed
Sensor (OSS) Low Input 7A1±45. . . . . . . . . . . . . . . . .
DTC P0723 Transmission Output Speed
Sensor (OSS) Intermittent 7A1±48. . . . . . . . . . . . . . .
DTC P0730 Transmission Incorrect
Gear Ratio 7A1±51. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0748 Pressure Control Solenoid
(PCS) (Force Motor) Circuit Electrical 7A1±54. . . . .
DTC P0753 Shift Solenoid A Electrical 7A1±56. . . . .
DTC P0758 Shift Solenoid B Electrical 7A1±59. . . . .
DTC P1790 ROM Transmission Side Bad
Check Sum 7A1±63. . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P1792 EEPROM Transmission Side
Bad Check Sum 7A1±64. . . . . . . . . . . . . . . . . . . . . . . .
DTC P1835 Kickdown Switch Always On 7A1±65. . .
DTC P1850 Brake Band Apply Solenoid
Malfunction 7A1±67. . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P1860 TCC Solenoid Electrical 7A1±71. . . . . . .

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.