1998 ISUZU TROOPER sensor

7A1±48
TRANSMISSION CONTROL SYSTEM (4L30±E)
DTC P0723 Transmission Output Speed Sensor (OSS) Intermittent
D07RW006
Circuit Description
Output speed information is provided to the PCM by the
OSS, which is a permanent magnet (PM) generator. The
PM generator produces a pulsing AC voltage. The AC
voltage level and number of pulses increases as the
speed of the vehicle increases. The PCM then converts
the pulsing voltage to output speed, which is used for
calculations. The vehicle speed can be displayed with a
scan tool.
This DTC detects a low output speed when there is a high
engine speed in a drive gear range. This is a type ªCº
DTC.
Conditions For Setting The DTC
In Park or Neutral:

Transmission output speed change is greater than
10,000 rpm.

Conditions met for 6 seconds.

Engine running time is greater than 2 seconds.
Not in Park or Neutral:

Transmission output speed change is greater than
512 rpm.

Conditions met for 0.075 seconds

Engine running time is greater than 2 seconds.

Engine vacuum is less than 70 kPa.

Output speed is greater than 1,380 rpm for 1 second.

NORAW±NOLAST < 60 rpm for 6 seconds.
NORAW: Latest raw data of output shaft speed.
NOLAST: Filtered pervious data of output speed.
Action Taken When The DTC Sets

Fixed to 4th gear.

Maximum line pressure.

Inhibit TCC engagement.
The PCM will illuminate the CHECK TRANS Lamp.
Conditions For Clearing The MIL/DTC

The PCM will turn off the 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

A OSS DTC P0723 will set when output speed has
been detected and is lost.

Inspect the wiring for poor electrical connection at the
PCM. 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:
5. This test checks the OSS circuit.
6. This test checks the integrity of the OSS.
8. This test checks the 5±volt and ground circuit of the
PCM.

TRANSMISSION CONTROL SYSTEM (4L30±E)7A1±49
DTC P0723 Transmission Output Speed Sensor (OSS) Intermittent
StepActionYe sNo
11. 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. Raise the drive wheels.
5. Start the engine.
6. Place the transmission in any drive range.
With the drive wheels rotating, does the ªTrans Output Speedº
increase with the drive wheel speed?
Go to Diagnostic
Aids
Go to Step 2
2Does the speedometer work?Go to Step 3Go to Step 4
3Check for the most current and/or incorrect calibration.
Is the calibration current?
Go to Step 16Go to Step 4
41. Turn the ignition ªoffº.
2. Disconnect the J3 (BLUE) PCM connector.
3. Using the J39200 DVOM, measure the resistance between
harness connector terminals J3±E1 and J3±E2.
Is the reading 3,000 ohms?
Go to Step 5Go to Step 6
51. Select AC volts.
2. Rotate the rear wheels, ensuring the driveshaft is turning.
Is the voltage greater than 0.5 volts?
Go to Step 7Go to Step 8
6Inspect circuits RED and WHT for a poor connection or an open
circuit.
Was a problem found?
Go to Step 17Go to Step 8
71. Reconnect the J3 (BLUE) PCM connector.
2. Disconnect the OSS harness from the OSS.
3. With the engine ªoffº, turn the ignition ªonº.
4. Using the J 39200 DVOM, measure the voltage at the OSS
harness connector terminals M15±1 and M15±2.
Is the reading between 4.0 to 5.1 volts?
Go to Step 16Go to Step 10
81. Remove the OSS.
2. Check the output shaft speed sensor rotor for damage or
misalignment. Refer to Speed Sensor (Extension Housing) in
Automatic Transmission (4L30±E) section.
Was a problem found?
Go to Step 17Go to Step 9
9Replace the OSS.
Is the replacement complete?
Go to Step 17Ð
10Was the reading in step 8 less than 4.0 volts?Go to Step 12Go to Step 11
11Was the reading in Step 8 greater than 5.1 volts?Go to Step 15Ð
12Using the J 39200 DVOM to chassis ground, measure the voltage
on circuit RED.
Is the reading between 4.0 to 5.1 volts?
Go to Step 13Go to Step 14
13Repair the open in circuit WHT.
Is the repair complete?
Go to Step 17Ð
14Check circuit RED for a short to ground or open.
Was a problem found and corrected?
Go to Step 17Go to Step 16

7A1±50
TRANSMISSION CONTROL SYSTEM (4L30±E)
DTC P0723 Transmission Output Speed Sensor (OSS) Intermittent (Cont'd)
StepNo Ye s Action
15Repair the short to B+ in circuit RED.
Is the repair complete?
Go to Step 17Ð
16Replace the PCM. Refer to Powertrain Control Module (PCM) in
Automatic Transmission (4L30±E) section.
Is the replacement complete?
Go to Step 17Ð
171. After the repair is complete, use the scan tool to select ªDTCº,
then ªClear Infoº function and operate the vehicle under the
following conditions:
Transmission output speed is greater than 101 rpm for 3
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±51
DTC P0730 Transmission Incorrect Gear Ratio
D07RT015
Circuit Description

The Powertrain Control Module (PCM) calculates the
slippage of the converter and transmission based
upon the engine speed, the output speed, and the
current gear ratio.

The slippage of the converter at a high enough engine
speed is low. The transmission should not slip more
than a given value when there is no shift.

This DTC detects a slip at each gear. This is a type
ªCº DTC.
Conditions For Setting The DTC

No Output Speed Sensor DTC(s) P0722, P0723.

Not in Park, Neutral, or Reverse.

Engine speed is greater than 3,500 rpm.
3 seconds since upshift.

3 seconds since downshift.

3 seconds since garage shift (N"D).

And one of the following conditions occur:
± Slip is greater than 508 rpm in 1st gear.
± Slip is greater than 468 rpm in 2nd gear.
± Slip is greater than 449 rpm on 3rd gear.
± Slip is greater than 440 rpm on 4th gear.

All conditions met for 5.5 seconds.Action Taken When The DTC Sets

Maximum line pressure.

The PCM will illuminate the CHECK TRANS Lamp.

7A1±52
TRANSMISSION CONTROL SYSTEM (4L30±E)
Conditions For Clearing The DTC/CHECK
TRANS Lamp

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

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

The DTC can also be cleared from memory when the
vehicle has made 40 warmup cycles without a failure
reported.

The PCM will cancel the DTC Actions Taken items
when the fault conditions no longer exist and the
ignition is cycles ªoffº long enough to power down the
PCM.
Diagnostic Aids

Check for intermittent output speed sensor circuit
problems.

Check for possible incorrect calibration. (PCM part
No., tire specification, and rear axle ratio)
Test Description
The numbers below refer to the step numbers on the
diagnostic chart:
3. This step checks for possible low fluid level causing
slipping resulting in an undefined gear ratio.
4. This step checks for correct gear ratios for
commanded gears.
5. This step checks for low line pressure.
DTC P0730 Transmission Incorrect Gear Ratio
StepActionYe sNo
1Visually inspect the transmission cooling system for fluid leaks.

Refer to Chart 16: Possible Causes of Transmission Fluid
Leaks of Mechanical/Hydraulic Diagnosis Symptoms Index in
Automatic Transmission (4L30±E) section
Was condition found and corrected?
Go to Step 6Go to Step 2
2Refer to Checking Transmission Fluid Level and Condition in
Automatic Transmission (4L30±E) section.
Has transmission fluid checking procedure been performed?
Go to Step 3
Go to Checking
Transmission
Fluid Level and
Condition in
Automatic
Transmission
(4L30±E) section
31. Install the scan tool.
2. Turn the ignition switch to the ªonº position.
3. Engine not running.
NOTE: Before clearing DTC(s) use the scan tool to record the
ªFailure Recordsº for reference, as data will be lost when the ªClear
Infoº function is used.
4. Record the Failure Record data.
5. Use the scan tool snapshot mode to record transmission gear
ratios.
6. Drive vehicle in transmission gear ranges 1, 2, 3, and D with
the engine speed is greater than 3,500 rpm for 5.5 seconds.
7. Record each transmission gear.
1st:2.73 ± 2.99
2nd:1.54 ± 1.71
3rd:0.93 ± 1.05
4th:0.66 ± 0.78
Does commanded gear ratio match ranges as shown?
Refer to
Diagnostic Aids
Go to Step 4
4Perform line pressure check.

Refer to Line Pressure Test in Automatic Transmission
(4L30±E) section.
Was condition found and corrected?
Go to Step 6Go to Step 5

TRANSMISSION CONTROL SYSTEM (4L30±E)7A1±65
DTC P1835 Kickdown Switch Always On
D07RW033
Circuit Description

When the driver presses the accelerator pedal down
fully, the kickdown switch closes, sending a ground
signal to the Powertrain Control Module (PCM).

This information is used to perform shifts at high
engine speed.

When the kickdown switch is closed, the Throttle
Position Sensor (TPS) is already is at 100%.

This DTC detects a closed kickdown switch when TP
angle is less than 70%.

This is a type ªDº DTC.
Conditions For Setting The DTC

No TPS DTCs P0122 or P0123.

TP angle is less than 70%.

Kickdown switch is ªonº.

All conditions met for 1 second.
Action Taken When The DTC Sets.

Kickdown mode control is off.

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 the wiring harness for a short to ground
between the PCM and kickdown switch.

Check the kickdown switch for failure.

Check kickdown adjustment.
Test Description
The numbers below refer to the step numbers on the
diagnostic chart:
2. This test checks for short to ground or kickdown
switch failure.
4. This test checks for regulation kickdown switch.

MANUAL TRANSMISSION7B±5
Manual Transmission Assembly
Transmission and Associated Parts
220RW108
Legend
(1) Gear Control Lever and Knob
(2) Transfer Control Lever and Knob
(3) Front Console Assembly
(4) Grommet Assembly
(5) Transfer Protector
(6) Rear Propeller Shaft
(7) Front Propeller Shaft
(8) Exhaust Pipe
(9) Backup Lamp, 4WD Indicator, and 1±2
Indicator Switch Harness Connector
(10) Speedometer Sensor and 2WD±4WD Actuator
Harness Connector(11) Slave Cylinder Heat Protector
(12) Harness Heat Protector
(13) Slave Cylinder
(14) Dust Cover
(15) Engine Rear Mount Nut
(16) Engine Rear Mount Bolt
(17) Engine Rear Mount
(18) Third Crossmember
(19) Flywheel Under Cover
(20) Transmission Retaining Bolt
(21) Transmission Assembly with Transfer Case

7B±6MANUAL TRANSMISSION
Removal
NOTE: Before remove the transmission and transfer
assembly from the vehicle, change the transfer mode to
2WD using push button on dash panel.
1. Remove engine hood.
2. Disconnect battery ground cable.
3. Remove the gear control lever knob.
4. Remove the front console assembly.
5. Remove the grommet assembly.
6. Remove the transmission control lever and transfer
control lever.
235RW014
7. Raise and support the vehicle with suitable jack
stand.
8. Remove transfer protector.
9. Remove the rear propeller shaft.
NOTE: Apply alignment marks on the flange at the both
front and rear side.
(4JX1)
401RW060
10. Remove the front propeller shaft.
NOTE: Apply alignment marks on the flange at both the
front and rear sides.
401RS003
11. Disconnect two oxygen sensor connectors from the
transmission harness (6VE1).
12. Remove the front and 3 way exhaust pipe (6VE1).
Remove the exhaust pipe with catalytic converter
(4JX1).
(4JX1)
150RW041