1998 ISUZU TROOPER transmission fluid

TRANSMISSION CONTROL SYSTEM (4L30±E)7A1±59
DTC P0758 Shift Solenoid B Electrical
D07RW009
Circuit Description

The shift solenoid B is a simple on/off solenoid
located in the main case valve body. It is normally
open. When the port is open, fluid pressure actuates
the shift valve. In first or second gear, the Powertrain
Control Module (PCM) energizes the solenoid to
close a fluid inlet port.

The solenoid is activated by current. This current is
procuded 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. In BACKUP
MODE or when the ignition is off, the HSD is turned
off.
This DTC detects a continuous open or short to ground in
the shift solenoid B circuit or shift solenoid B. This is a
type ªCº DTC.
Conditions For Setting The DTC

Ignition is ªonº, Engine ªrunº.

Battery voltage is between 10 and 16 volts.

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 for 0.33 seconds.
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

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.

7A1±66
TRANSMISSION CONTROL SYSTEM (4L30±E)
DTC P1835 Kickdown Switch Always On
StepActionYe sNo
11. Install the scan tool.
2. With the engine ªonº, 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.
Does the scan tool display ªKickdown switchº ªlowº (closed
switch)?
Go to Step 2Go to Step 3
21. Turn the ignition ªoffº.
2. Disconnect the J3 (BLUE) PCM connector.
3. Using the J39200 DVOM, check a continuity between PCM
connector terminal J3±F11 and ground.
Is there a continuity?
Go to Step 4Go to Step 7
3The TP angle goes from 0% to 100% with the accelerator pedal
depressed.
Is the kickdown switch ªonº when TP angle is below 70%?
Go to Step 5
Go to Diagnostic
Aids
41. Disconnect the kickdown switch connector B±10.
2. Using the J39200 DVOM, check a continuity between
terminals B10±1 and B10±2.
Is there a continuity?
Go to Step 6Go to Step 8
5Adjust the kickdown switch.
Is the kickdown switch ªonº when TP angle is above 95%?
Go to Step 9Ð
6Replace the kickdown switch.
Is the replacement complete?
Go to Step 9Ð
7Replace the PCM. Refer to Powertrain Control Module (PCM) in
Automatic Transmission (4L30±E) section.
Is the replacement complete?
Go to Step 9Ð
8Repair the short to ground in circuit LT BLUE.
Is the repair complete?
Go to Step 9Ð
91. After the repair is complete, use the scan tool to select ªDTCº,
then ªClear Infoº function and ensure the following condition is
met:
The torque converter stator temperature switch circuit does not
indicate a hot mode when the transmission fluid temperature is
less than 60
C (140
F) for at least 5 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±67
DTC P1850 Brake Band Apply Solenoid Malfunction
D07RW009
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 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 1.3 seconds.
Action Taken When The DTC Sets

Inhibit brake band apply solenoid.

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.

TRANSMISSION CONTROL SYSTEM (4L30±E)7A1±71
DTC P1860 TCC Solenoid Electrical
D07RW010
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 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 solenoid is
used in conjunction with the TCC solenoid to regulate fluid
to the torque converter. The TCC 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 solenoid. This is a
type ªDº DTC.
Conditions For Setting The DTC

Battery voltage is between 10 and 16 volts.

No shift solenoid A DTC P0753.

No shift solenoid B DTC 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 0.25 seconds.
Action Taken When The DTC Sets

Inhibit TCC engagement.
The PCM will not illuminate the CHECK TRANS
Lamp.
Conditions For Clearing The MIL/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 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.
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.

8DÐ284 WIRING SYSTEM
Anti-lock Brake System (ABS)
General Description
The circuit consists of EHCU (Electronic Hydraulic
Control Unit), wheel speed sensor, GÐsensor,
stoplight switch or brake switch (w/cruise control),
backup light switch, transmission switchÐ1, 2,
indicator light and data link connector.
EHCU controls brake fluid pressure applied to front
and rear wheels to prevent wheels from locking by
using speed sensor and GÐsensor signals.
Based on wheel speed signals from speed sensor,
EHCU activates solenoid valves incorporated into
the control unit to increase, maintain or decrease
brake fluid pressure.
Refer to AntiÐlock Brake System in Brakes section.

METER AND GAUGE8E–1
METER AND GAUGE
CONTENTS
Service Precaution 8E–1. . . . . . . . . . . . . . . . . . . . . .
General Description 8E–1. . . . . . . . . . . . . . . . . . . . .
Meter Assembly 8E–2. . . . . . . . . . . . . . . . . . . . . . . . .
General Description 8E–2. . . . . . . . . . . . . . . . . . . . .
Layout for Meters/Gauges, Warning Lights,
Indicator Lights and Illumination Lights 8E–2. . .
Table for Meter/Gauge Connector Terminal
Connections 8E–8. . . . . . . . . . . . . . . . . . . . . . . . . .
Removal 8E–14. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 8E–14. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Warning Light Bulb, Indicator Light Bulb,
Illumination Light Bulb, A/T Indicator
Light Bulb 8E–14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removal 8E–14. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 8E–14. . . . . . . . . . . . . . . . . . . . . . . . . . . . Vehicle Speed Sensor 8E–15. . . . . . . . . . . . . . . . . . .
Removal 8E–15. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 8E–15. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel Tank Unit 8E–15. . . . . . . . . . . . . . . . . . . . . . . . . .
Removal 8E–15. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 8E–15. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Multi Meter 8E–16. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removal 8E–16. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 8E–16. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Ambient Sensor 8E–16. . . . . . . . . . . . . . . . . . . . . . . . .
Removal 8E–16. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 8E–16. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Main Data and Specifications 8E–17. . . . . . . . . . . . .
Service Precaution
WARNING: I F S O E Q U IPPED WITH A
SUPPLEMENTAL RESTRAINT SYSTEM (SRS),
REFER TO THE SRS COMPONENT AND WIRING
LOCATION VIEW IN ORDER TO DETERMINE
WHETHER YOU ARE PERFORMING SERVICE ON OR
NEAR THE SRS COMPONENTS OR THE SRS
WIRING. WHEN YOU ARE PERFORMING SERVICE
ON OR NEAR THE SRS COMPONENTS OR THE SRS
WIRING, REFER TO THE SRS SERVICE
INFORMATION. FAILURE TO FOLLOW WARNINGS
COULD RESULT IN POSSIBLE AIR BAG
DEPLOYMENT, PERSONAL INJURY, OR
OTHERWISE UNNEEDED SRS SYSTEM REPAIRS.
CAUTION: Always use the correct fastener in the
proper location. When you replace a fastener, use
ONLY the exact part number for that application.
ISUZU will call out those fasteners that require a
replacement after removal. ISUZU will also call out
the fasteners that require thread lockers or thread
sealant. UNLESS OTHERWISE SPECIFIED, do not
use supplemental coatings (Paints, greases, or other
corrosion inhibitors) on threaded fasteners or
fastener joint interfaces. Generally, such coatings
adversely affect the fastener torque and the joint
clamping force, and may damage the fastener. When
you install fasteners, use the correct tightening
sequence and specifications. Following these
instructions can help you avoid damage to parts and
systems.
General Description
The circuit consists of the starter switch, meter assembly,
vehicle speed sensor, transmission switch, lighting
switch, turn signal switch, thermo unit, oil pressure unit,
Powertrain Control Module (PCM), fuel tank unit, 4WD
switch, oil pressure switch, parking brake switch, brake
fluid switch, seat belt switch, illumination controller, multi
meter and ambient sensor.