wheel ISUZU TROOPER 1995 Workshop Manual

New or service sensors will already have the
compound
applied to the threads. If a sensor is
removed
from an engine and iffor any reason it
is to be reinstalled, the threads must have anti­
seize compound
applied before reinstallation.
•
Apply anti-seize compound or equivalent to
threads of oxygen sensor if necessary.
• Tighten the oxygen sensor to the specified
torque.
1~1 Torque N·m (lb·ft) 55 (40)
1. H02S wiring connector
THROTTLE POSITION (TP) SENSOR
Fig. 6E2-59
E) REMOVAL
Preparation: • Battery negative cable.
1. Throttle Position (TP) sensor wiring connector
2. TP sensor fixing screw
3. TP sensor
I••IINSTALLATION
3. TP sensor
2. TP sensor fixing screw
• Tighten the fixing screw to the specified torque.
~~~ Torque N·m (lb·in) I 2 (18)
• Use a "Scan tool" to check TP sensor output
voltage with throttle closed, should be under
0.85 volts. If over 0.85 volts, check for binding
throttle shaft, or TP sensor lever. If all OK,
replace TP sensor.
1.
TP sensor wiring connector
DRIVEABILITY AND EMISSIONS 6E2-1 07
MANIFOLD ABSOLUTE PRESSURE
(MAP) SENSOR
1. Vacuum hose
) 0~
2 .• ,.~,,~,~
conne~ JJJ
4. Sensor
Fig. 6E2-60
E) REMOVAL
Preparation: • Battery negative cable.
1. Vacuum hose
2. Electrical connector
3. Attaching screws
4. Sensor
I••IINSTALLATION
4. Sensor
3. Attaching screws
2. Electrical connector
1. Vacuum hose
VEHICLE SPEED SENSOR (VSS)
Refer to INSTRUMENT PANEL CLUSTER AND
CONSOLE of this manual for replacement of vehicle
speed sensor located in instrument panel.
POWER STEERING PRESSURE (PSP)
SWITCH
Refer to STEERING, SUSPENSION, TIRES AND
WHEELS for service of the power steering pressure
switch.
PARK/NEUTRAL
SWITCH POSITION
(PNP}
See
Section AUTOMATIC TRANSMISSION GENERAL
INFORMATION Section for park/neutral position
switch.
"On-Vehicle Service" and adjustment
procedures are
also listed there.

6E2-112 DRIVEABILITY AND EMISSIONS
CHART C-1E
POWER STEERING PRESSURE (PSP) SWITCH DIAGNOSIS
Circuit Description:
The Power Steering Pressure
(PSP) Switch is normally open to ground, and GRNIYEL wire will be near the battery
positive
voltage.
Turning the steering wheel increases power steering oil pressure and its load on an idling engine. The pressure
switch
will close before the load can cause an idle problem.
Closing
the switch causes GRN/YEL wire to read less than 1 volt. The Engine Control Module (ECM) will increase
the
idle air rate and disengage the air conditioning relay.
•
A pressure switch that will not close, or an open GRNIYEL wire, may cause the engine to stop, when power
steering loads are high.
• A switch that will not open or a GRNIYEL wire shorted to ground, may affect idle quality and will cause the air
conditioning
relay to be de-energized.
Test Description:
Numbers
below refer to circled numbers on the diagnostic chart.
CD Different makes of "Scan tools" may display the state of this switch in different ways. Refer to "Scan tool"
operator's manual to determine how this input is indicated.
® Checks to determine if GRNIYEL wire is shorted to ground.
@ This should simulate a closed switch.
POWER STEERING PRESSURE SWITCH ENGINE
CONTROL
MODULE(ECM)
I SIGNAL
r
BLU ---(~ BLU --+8 .. •f---BLU --{~ GRN/YEL ~ ~ B +
(LOCATED IN THE POWER
STEERING PUMP HIGH PASSENGERS CHASSIS PRESSURE LINE)
SIDE GROUND
FENDER
Fig. 6E2-65
•

DRIVEABILITY AND EMISSIONS 6E2-113
CHART C-1E
POWER STEERING PRESSUR,.E (PSP) SWITCH DIAGNOSIS
CD • WITH ENGINE IDLING, "SCAN TOOL" SHOULD DISPLAY POWER STEERING PRESSURE (PSP) SWITCH TO BE "NORMAL" DOES IT?
•
TURN STEERING WHEEL AGAINST STOP. ® • DISCONNECT PSPS. • "SCAN TOOL" SHOULD DISPLAY "HIGH"
DOES IT? • "SCAN TOOL" SHOULD INDICATE "NORMAL".
@ • DISCONNECT PSP SWITCH HARNESS CONNECTOR.
• JUMPER GRNIYEL WIRE TO GROUND. • "SCAN TOOL" SHOULD DISPLAY "ON" DOES IT? DOES
IT?
POOR CONNECTION OR OPEN GRN/YEL WIRE OR FAULTY ENGINE
CONTROL MODULE. GRN/YEL
WIRE SHORTED TO GROUND OR FAULTY ENGINE
CONTROL MODULE
CLEAR
DIAGNOSTIC TROUBLE CODES AND CONFIRM "CLOSED LOOP" OPERATION AND NORMAL "CHECK ENGINE" MALFUNCTION
INDICATOR LAMP OPERATION.

1~1 Measure (If Installing a New Idle Air
Control (lAC) Valve) (Fig. 6E2-82)
• Distance between tip of idle air control (lAC)
valve pintle and mounting flange.
-
If greater than 28 mm, finger pressure to
slowly retract the pintle. The force required
to retract the pintle
of a new valve will not
cause damage to the valve.
Fig. 6E2-82
E) INSTALLATION
3. lAC valve assembly
2. lAC valve attaching screw
1. lAC valve electrical connector
MINIMUM THROTTLE BODY (TB)
POSITION CHECK
The minimum throttle body (TB) position (throttle stop
screw) adjustment
for the 3.2L should not be
considered the
"minimum idle speed", as on other fuel
injected engines. Low internal friction and provision
for slight production variations and various operation
altitudes resulted in a calibrated
minimum TB position
which is too
low to allow most engines to idle. The
adjustment is preset at the factory and no further
adjustment should be necessary.
If there is a complaint of high idle speed, vacuum leaks
should be considered the
most likely cause. Because
the Engine
Control Module (ECM) "learns" Idle lAC, it is
even less likely
that a stalling complaint would be due
to
an incorrect minimum TB position. In either case,
the
"Symptoms," Section "6E2-B" and lAC valve check
CHART C-2C should be referred to.
If it is determined that the minimum TB position is
suspect,
be sure lAC valve is not "lost'' (not actually at
the location indicated by current
lAC "counts"). The
lAC valve could be "lost" if ECM power has been
interrupted
with the ignition "ON", or the lAC valve has
been disconnected
with the engine running since the
last reset,
as described previously in this section in the
"lAC Valve Assembly" general description.
DRIVEABILITY AND EMISSIONS 6E2-127
The minimum TB position may be checked using the
following procedure.
1. Block drive wheels, and apply parking brake.
2. Connect "Scan tool" to the data link connector.
3. Start engine and allow to reach operating
temperature (about
go•q and "Closed Loop".
4. A/T-shift to DRIVE ("D") and then back to neutral
("N").
5. Select power steering pressure switch input on
"Scan tool". With air conditioning and all electrical
accessories
"OFF", transmission in natural, "Scan
tool" should read "OFF" or "NORMAL". (If not,
refer to
CHART C-1 E to diagnose and repair faulty
power steering pressure switch circuit before
proceeding).
Allow idle to stabilize.
6. Select lAC valve display on "Scan tool", and read
lAC valve counts. If between 5-45 counts, the
minimum
TB position adjustment is acceptable. It
is important to allow idle speed to stabilize to
assure correct counts are determined.
If counts in step 6 are too low, check for intake air
(vacuum) leaks at hoses,
TB and intake manifold or
damaged throttle lever and correct as necessary.
Also, refer to
CHART C-2C facing page "Diagnostic
Aids". If no vacuum leaks or other cause of
excessive air into the intake are found, it may be
necessary
to replace the TB to correct the low idle
speed problem. Refer to
"TB Replacement" in this
section.
If counts in Step 6 are too high, check for damaged
throttle lever or airflow restriction by the
TB. If no
problem is evident, remove inlet air
duct at the TB,
and
clean residue from inside of TB bore and from
edges of TB using carburetor cleaner and a shop
towel. (Do Not use a cleaner that contains methyl
ethyl ketone.
It is an extremely strong solvent, and
not necessary for this type of deposit). Re-check
"Scan tool" lAC valve counts, per the preceding
procedure.
If counts are still too high it may be necessary to
replace the
lAC valve or the TB assembly, If no
vacuum leaks are indicated
or engine loads are
present.
Minimum Throttle Body (TB) Position
(Non-Adjustable)
\fl CAUTION:
VI • It is extremely unlikely that this adjustment will
ever be necessary on a TB that has not been
tampered
with after production! If idle
revolution per minute is low, you may need
to
replace the TB to correct the low idle speed.

DRIVEABILITY AND EMISSIONS 6E2-131
CHART C-2C
IDLE AIR CONTROL (lAC) SYSTEM CHECK
CD • IGNITION "OFF", CONNECT IDLE AIR CONTROL (lAC) DRIVER* TO lAC VALVE. • SET PARKING BRAKE, BLOCK WHEELS, AIR CONDITIONING "OFF".
• IDLE ENGINE IN PARK (A/T) OR NEUTRAL (MIT). • INSTALL "SCAN TOOL" AND DISPLAY REVOLUTION PER MINUTE (RPM). • WITH lAC DRIVER, EXTEND AND RETRACT lAC VALVE. • ENGINE SPEED SHOULD DECREASE AND INCREASE AS lAC IS CYCLED.
I
1 I • RPM CHANGES I NO RPM CHANGE I
I I • RPM SHOULD CHANGE SMOOTHLY
WITH EACH • CHECK lAC PASSAGES.
I FLASH OF THE lAC DRIVER LIGHT FROM 700 RPM • IF OK, REPLACE lAC.
TO ABOUT 1500 RPM. DOES IT?
I
~ cf
• INSTALL APPROPRIATE lAC NODE LIGHT* IN • CHECK lAC PASSAGES.
l ENGINE CONTROL MODULE HARNESS. • IF OK, REPLACE lAC. ®
• CYCLE lAC
DRIVER AND NODE LIGHTS.
• BOTH LIGHTS SHOULD CYCLE RED AND GREEN BUT NEVER "OFF" AS RPM IS CHANGED OVER
ITS RANGE. DO THEY?
I
cf ~ IF CIRCUIT(S) DID NOT TEST GREEN AND RED, CHECK •
USING THE OTHER CONNECTOR ON THE lAC
FOR: DRIVER
PIGTAIL, CHECK RESISTANCE
•
FAULTY CONNECTOR TERMINAL CONTACTS. ACROSS
lAC COILS.
• OPEN CIRCUITS INCLUDING CONNECTIONS. •
SHOULD BE 40 TO 80 OHMS BETWEEN lAC
• CIRCUITS SHORTED TO GROUND OR VOLTAGE. TERMINALS "A" TO "B" AND "C" TO "D".
• FAULTY ENGINE CONTROL MODULE CONNECTION I OR ENGINE CONTROL MODULE.
~
l REPAIR AS NECESSARY AND RETEST. l NOT OK I .
_l
• CHECK RESISTANCE BETWEEN lAC I REPLACE lAC VALVE I TERMINALS "B" AND "C" AND "A" AND RETEST. AND "D". • SHOULD BE INFINITE.
I
~
l
I NOT OK I
]
AC DRIVER AND NODE LIGHT REQUIRED. * I J lAC VALVE AND CIRCUIT OK. I REPLACE lAC VALVE J 37027 FROM KENT-MOORE, INC. REFER TO "DIAGNOSTIC AIDS" ON AND RETEST. FACING~
~ CLEAR DIAGNOSTIC TROUBLE CODES AND CONFIRM "CLOSED LOOP" OPERATION AND NORMAL "CHECK ENGINE" MALFUNCTION
INDICATOR LAMP OPERATION.
------

6E2-138 DRIVEABILITY AND EMISSIONS
SECTION C4
ELECTRONIC IGNITION (EI) SYSTEM/IGNITION CONTROL (IC)
CONTENTS
General Description . . . . . . . . . . . . . . . . . . . . . 6E2-138
Purpose
............................ 6E2-138
Operation
........................... 6E2-138
Results of Incorrect Operation . . . . . . . . . . . 6E2-139
How diagnostic trouble code (DTC) 42 is
Determined ........................ 6E2-139
Diagnosis. . . . . . . . . . . . . . . ............. 6E2-139
Diagnostic
trouble code (DTC) 12 . . . . . . . . . 6E2-139
On-Vechicle Service . .

. . . . . . . . . . . . . . . . . . . 6E2-139
Electronic Ignition (EI) Assembly .......... 6E2-139
Crankshaft Position (CKP) Sensor ......... 6E2-140
Ignition Coil
.......................... 6E2-140
Ignition Control
Module (ICM) ............ 6E2-140
Ignition
Timing ....................... 6E2-140
Chart
C-4D-1 Electronic Ignition (EI) misfire
at
Idle .............................. 6E2-142
Chart C-4D-2 Electronic Ignition (EI) misfire
Under Load .......................... 6E2-144
GENERAL DESCRIPTION
PURPOSE
The Electronic Ignition (EI) system controls fuel
combustion by providing a spark to ignite the
compressed
air/fuel mixture at the correct time. To
provide improved engine performance,
fuel economy,
and
control of exhaust emissions, the Engine Control
Module
(ECM) controls spark advance timing with the
Ignition Control (IC) system.
OPERATION
The "EI" is a "waste spark" system in which 2 plugs are
fired
simultaneously from one coil. The spark plugs are
paired
to a coil, so that when both fire, one cylinder is
on the compression stroke and the other is on exhaust.
There is
Iitie resistance across the plug gap on the
exhaust stroke, so the
plug requires very little voltage
to fire, thereby providing the other plug (compression)
with maximum available voltage.
The system uses a magnetic Crankshaft Position (CKP)
sensor which protrudes into the block, within
approximately .050" of the crankshaft reluctor. The
reluctor is a special wheel cast on the crankshaft that
has seven machined
slots, six of which are equally
spaced 60° apart). The seventh slot is spaced 1 oo from
one
of the other slots. As the reluctor rotates with the
crankshaft, the
slots change the magnetic field of the
sensor, causing
an induced voltage pulse.
By counting the time between pulses, the Ignition
Control Module (ICM)
can recognize the pulse of the
seventh
slot (sync pulse). Based on this sync pulse, the
module sends the reference signal to the ECM to
calculate CKP (used to fire coils in correct sequence)
and engine speed.
To
properly control timing, the ECM relies on the
following information:
• Engine load (manifold absolute pressure or
vacuum).
• Atmospheric (barometric) pressure.
• Engine temperature.
• Intake air temperature.
• CKP
• Engine speed (revolution per minute).
The ignition
control system consisits of the "EI"
assembly (coils, module,
and CKP sensor), ECM and
connecting wires. These circuits
perform the following
functions:
• "EI" reference
The CKP sensor sends a signal to the ICM which
generates a reference
pulse which is sent to the
ECM. The ECM uses this signal to calculate CKP
and engine speed (also used to trigger the
injector).
• Reference ground (GND)
This wire is GNd through the module and makes
sure the GNd circuit has no
voltage drop between
the
ICM and the ECM, which if open, could affect
performance.
• Bypass
At about 400 revolution per minute, the ECM
applies 5 volts to this circuit to switch spark timing
control from the ICM to the ECM. An open or
grounded bypass circuit
will set a diagnostic
trouble code 42 and the engine will run at base
timing,
plus a small amount of advance built into
the
ICM.
• IGNITION CONTROL (IC)
The ECM uses this circuit (when bypass voltage is
applied) to trigger the "EI" module. The ECM uses
the
CKP to base its calculation of the amount of
spark advance needed under present engine
conditions.
•

(
f
CROSS
SECTION
"'T1 ce· ~ .....
1. TORQUE CONVERTER-CLUTCH (TCC)
5.
REVERSE
CLUTCH (RC)
2.
FOURTH CLUTCH (C4)
6.
SECOND
CLUTCH (C2)
3.
OVERRUN CLUTCH
(OC)
7.
THIRD
CLUTCH (C3)
4. OVERDRIVE
UNIT
8.
RAVIGNEAUX
PLANETARY
GEARSET
9.
BRAKE
BAND (B)
10.
OVERDRIVE
FREE WHEEL
(ONE
WAY
CLUTCH) (OFW)
11.
SPRAG
FREE WHEEL
(ONE WAY
CLUTCH)
(PFW)
(
(') 0 2 CJ) -1 ::D c (') ::! 0 2
)> c: -f 0 s: )> -f n -f ::D )> 2 en s: c;; en s 2 -;; ,... w 0 I m -...... )> I w

7A-12 AUTOMATIC TRANSMISSION (4L30-E)
RANGE REFERENCE CHART
1-2/3-4 2-3 0/DRIVE OVERRUN FOURTH THIRD REVERSE SECOND BAND ROLLER ENGINE RANGE
GEAR SOL
SOL
CLUTCH CLUTCH
CLUTCH CLUTCH CLUTCH CLUTCH MBLY BRAKING N_c. N.O.
(OFW) (OCl
(C4)
(C3) (RC)
(C2) (B)
P-N OFF
ON APPLIED NO
R REVERSE OFF
ON LD APPLIED APPLIED LD NO
1ST OFF
ON LD APPLIED LD APPLIED NO
2ND ON ON LD APPLIED APPLIED FW APPLIED YES D 3RD ON
OFF LD APPLIED APPLIED APPLIED NE YES
4TH OFF OFF FW APPLIED APPLIED APPLIED NE YES
1ST OFF ON
LD APPLIED LD APPLIED NO
3 2ND ON ON LD APPLIED APPLIED FW APPLIED
YES
3RD ON OFF LD APPLIED APPLIED APPLIED NE YES
1ST OFF
ON LD APPLIED APPLIED LD APPLIED YES 2 2ND ON
ON LD APPLIED APPLIED FW APPLIED YES
L 1ST OFF
ON LD APPLIED APPLIED LD APPLIED
YES
LD : LOCKED IN DRIVE FW: FREEWHEELING NE : NOT EFFECTIVE
TORQUE CONVERTER CLUTCH
B
C4lil RC 1/f ~
C2 I I
C3
PFW ~
Qe OFW
Qe: ENGINE
TORQUE Qt: TURBINE TORQUE Qo: OUTPUT SHAFT TORQUE

7 A-20 AUTOMATIC TRANSMISSION (4L30-E)
CHECKING TRANSMISSION FLUID
LEVEL AND CONDITION
Checking fluid level and condition (color and odor)
at
regular intervals will provide early diagnosis
information about the transmission. This inform­
ation may be used to correct a condition that, if not
detected early, could result in major transmission
repairs.
IMPORTANT: When new, automatic transmission
fluid is red in color. As the vehicle is driven, the
transmission
fluid will begin to look darker in color.
The
color may eventually appear light brown.
A DARK
brown color with burnt odor may indicate
excessive
fluid deterioration and signal a need for
fluid change.
FLUID LEVEL
When adding
or changing fluid, use only DEXRON
®-Ill.
Refer to the Maintenance and Lubrication (Section 0
of this manual) for maintenance information and
servicing
interval.
\f CAUTION: DO NOT OVERFILL
Overfilling will cause foaming, loss ~f fluid,
abnormal shifting and possible damage to
the transmission.
1. Start engine and drive vehicle until normal AfT
oil operating temperature is reached:
NOTE: The automatic transmission fluid level
must be checked with the vehicle at normal
A/T oil operating temperature: 75 TO 85°C
(167 TO 185°F) MEASURED WITH TECH1 SCAN
TOOL.
Temperature will greatly affect transmission
fluid level.
If the vehicle is not at normal AfT oil operating
temperature and the proper checking
procedures are
not followed, the result could
be a false reading of the fluid level indicator
and
an incorrect adjustment of the fluid level.
2. Park vehicle on level ground.
3. Move gear selector to "Park".
4. Apply parking brake and block wheels.
5. Allow vehicle to idle for 3 minutes with all
accessories turned off.
6. Check fluid level with engine running at idle:
Fluid should
be in "HOT" area on AfT dipstick
(Fig. 7A-6).
Check also color and condition (Refer to next
page.)
Hot
Cold ---IIU 0
0
Min
Dipstick
Fig. 7A-6
\f CAUTION:
DO NOT CHECK FLUID LEVEL UNDER THESE
CONDITIONS: •
At high ambient temperature above 30°C
(86°F).
Immediately after driving at sustained highway
speeds.
• In heavy city traffic during hot weather.
If vehicle is towing a trailer.
If the vehicle has been operated under these
conditions,
shut the engine off and allow the
vehicle to "cool" for thirty (30) minutes. After the
cool-down period, restart the vehicle and continue
from step 2 above.
'~I
......

STALL TEST
The stall test allows you to check the transmission for
internal abrasion and the oneway clutch for slippage.
Torque converter performance can also be evaluated.
The
stall test results together with the road test results
will identify transmission components requiring ser­
vicing or adjustment.
Stall Test Procedure:
1. Check the level of the engine coolant, the engine
oil, and the automatic transmission fluid.
Replenish
if necessary.
2. Block the wheels and set the parking brake.
3. Connect a tachometer to the engine.
4. Start the engine and allow it to idle until the
engine coolant temperature reaches
70 -8o·c
(158 -176.F).
5. Hold the brake pedal down as far as it will go.
6. Place the selector in the "D" range.
7. Gradually push the accelerator pedal to the floor.
The throttle valve
will be fully open.
Note the engine speed at which the tachometer
needle stabilizes.
Stall Speed
\fl NOTE:
2150 ± 150 rpm (SOHC)
2200 ± 150 rpm (DOHC)
VI Do not continuously run this test longer than 5
........, seconds.
8. Release the accelerator pedal.
9. Place the selector in the "N" range.
10. Run the engine at 1,200 rpm for one minute.
This
will cool the transmission fluid.
11. Repeat Steps 7-10 for the "3", "2", "L" and "R"
ranges.
AUTOMATIC TRANSMISSION (4L30-E) 7A-41