check engine ISUZU TROOPER 1995 Workshop Manual

DRIVEABILITV AND EMISSIONS 6E2-161
SECTION C-1 0
AIR CONDITIONING (A/C) COMPRESSOR CLUTCH CONTROL
SYSTEM
CONTENTS
General Description ..................... 6E2-161 On-Vehicle Service ...................... 6E2-161
Operation ........................... 6E2-161 Chart C-10 Air Conditioning (A/C) System
Diagnosis ............................. 6E2-161 Functional Check ...................... 6E2-162
GENERAL DESCRIPTION
OPERATION
This system consists of a high pressure cut-out switch,
Air Conditioning (A/C) compressor
relay, A/C thermo
switch relay, A/C controller and the compressor.
The high pressure cut-out switch
(normally closed),
opens when the head pressure gets too high. This will
disable
the A/C clutch, before damage can occur to the
compressor or other
A/C components.
When
A/C control switch is "ON" and the high pressure
switch and thermo switch are
closed, a request signal
is sent to the Engine Control Module (ECM). The ECM
will then energize the A/C clutch through the A/C
clutch relay. The A/C controller which is separate from
the ECM will then turn the A/C cooling fan "ON".
The A/C controller controls the A/C cooling fan, as well
as sending a signal to the ECM on model equipped with
automatic transmission.
The
ECM will disable the A/C clutch during Wide Open
Throttle,
or high power steering loads. The ECM has a
slight delay for clutch engagement to allow for the idle
to slightly increase. Refer to CHART C-1 0 for wiring and
circuit description.
DIAGNOSIS
Chart C-10 should be used for the electrical portion of
the A/C circuit. Section 1 B should be used for
diagnosing the refrigerant portion of the system. The
"Scan tool" will be used in diagnosing the system, as it
has the ability to read the A/C request inputto the ECM,
as well as displaying when the ECM has commanded
the
A/C clutch "ON".
ON-VEHICLE SERVICE
For removal and replacement of A/C components,
refer to
A/C (SECTION 1 B) in this Manual.

6E2-162 DRIVEABILITY AND EMISSIONS
CHART C-10
AIR CONDITIONING (A/C) SYSTEM FUNCTIONAL CHECK
Circuit Description:
When the Air Conditioning (A/C) diagnostic test mode is selected, the Engine Control Module (ECM) will supply a
ground to the
A/C clutch relay. Battery positive voltage is then supplied to the A/C clutch through the completing
of circuit through the thermo switch relay, which is part of the A/C "ON/OFF" switch circuit. If the A/C system
exhibits high pressure or
an overheating condition exist, the A/C system will be disabled by the open of the A/C
high pressure switch or the A/C thermo switch.
Diagnostic Aids:
The A/C high pressure switch is located in the high pressure side A/C hose.
The
thermo cut-out switch is part of the A/C evaporator mounted under the dash. For further information about
the
A/C system, refer to A/C (SECTION 1 8).
BRN
TONC FUSE
NC HIGH
PRESSURE SWITCH
(LOCATED IN
RECEIVER/DRYER)
LTGRN
BRN
NC Switch
NC DIODE
BRN a GRY!YEL
THERMO CUT­OUT RELAY
LTGRN PNK/ GRN
NCCOMP CLUTH RELAY
PARTOF1-­FAN I SWITCH I I CIRCUIT I __ I
BLK THERMO CUT-OUT MODULE j_
Fig. 6E2-100
ENGINE
CONTROL
MODULE (ECM)
NC COMPRESSOR CLUTCH RELAY DRIVER OUTPUT
NC REQUEST INPUT

DRIVEABILITV AND EMISSIONS 6E2-163
CHART C-10
AIR CONDITIONING (A/C) SYSTEM FUNCTIONAL CHECK
IGNITION "ON" ENGINE RUNNING.
CYCLE AIR CONDITIONING (A/C) SWITCH "ON" AND "OFF". A/C COMPRESSOR CLUTCH SHOULD
CYCLE "ON" AND "OFF"
DOES IT?
$
$
"SCAN TOOL" INSTALLED.
NO PROBLEM FOUND, REFER TO)>e€TIO'N REQUEST A/C "1B", AIR CONDITIONING"
"SCAN TOOL" SHOULD DISPLAY "YES" FOR FOR SERVICE OF A/C SYSTEM A/C REQUEST AND "ON" FOR A/C CLUTCH.
DOES IT?
$
$
IGNITION "ON", ENGINE "OFF". USING TEST BASIC A/C PROBLEM. REFER TO~ LIGHT, BACK PROBE ENGINE CONTROL MODULE "1B", AIR CONDITIONING"
TERMINAL C9 WITH A/C REQUESTED. LIGHT
SHOULD BE "ON". IS IT?
$ $
USING TEST LIGHT CONNECTED TO BATTERY IGNITION "OFF". REMOVE A/C THERMO
POSITIVE VOLTAGE, BACK PROBE ENGINE RELAY. IGNITION "ON" A/C REQUESTED, CONTROL MODULE TERMINAL PROBE THE GRN/WHT WIRE OF RELAY. "A2". LIGHT SHOULD BE "ON". LIGHT SHOULD BE "ON" IS IT?
IS IT?
I
$ $
~ $ OPEN IN PNK/GRN WIRE I OPEN IN GRN/WHTJ OPEN GRN WIRE
OPEN GRY/YEL WIRE OR WIRE. OR OR FAULTY A/C THERMO SWITCH FAULTY FAULTY A/C CLUTCH RELAY. OR COMPRESSOR RELAY. FAULTY THERMO SWITCH RELAY.
CLEAR DIAGNOSTIC TROUBLE CODES AND CONFIRM "CLOSED LOOP" OPERATION AND NO "CHECK ENGINE" MALFUNCTION INDICATOR LAMP.

DRIVEABILITV AND EMISSIONS 6E2-165
DIAGNOSIS
FUNCTIONAL CHECK OF POSITIVE
CRANKCASE VENTILATION (PCV)
If an engine is idling rough, check for a clogged PCV or
plugged hose. Replace as required. Use the following
procedure.
1. Remove PCV from rocker arm cover.
2. Run the engine at idle.
3. If there is no vacuum at valve, check for plugged
hoses or manifold port, or PCV.
Replace plugged or deteriorated hoses.
4. Stop the engine and remove PCV. Remove
PCV hose. Inspect metered orifice for being
restricted or
plugged. If restricted clean orifice.
With this system, any
blow-by in excess of the system
capacity (from a
badly-worn engine, sustained heavy
load, etc.) is exhausted into the intake manifold and is
drawn into the engine. Proper
operation
of the PCV System is dependent
upon a
sealed engine. If oil sledging or dilution is
noted, and the PCV System is functioning properly,
malfunction
indicator lamp for possible cause and
correct to ensure that system
will function as intended.
RESULTS OF INCORRECT OPERATION
A plugged valve or hose may cause:
• Rough idle.
• Stalling
or slow idle speed.
• Oil leaks.
• Oil
in air cleaner.
• Sludge
in engine.
ON-VEHICLE SERVICE
An engine which is operated without any crankcase
ventilation can be damaged. Periodically, inspect the
PCV, hoses
and clamps and replace any showing
signs
of deterioration.

6F-2 ENGINE EXHAUST (V6 3.2L)
When inspecting or replacing exhaust system
components, make sure there is adequate
clearance
from all points on the underbody to prevent over­
heating the
floor pan and possible damage to the
passenger
compartment insulation and trim materials.
Check complete exhaust system and nearby body
areas and rear compartment lid for broken, damaged,
missing
or mispositioned parts, open seams, holes,
loose
connections or other deterioration which could
permit exhaust fumes to seep into the rear
compartment or passenger compartment. Dust or
water in the rear compartment may be an indication of
a problem in one of these areas. Any faulty areas
should be corrected immediately.
HANGERS
Various types of hangers are used to support exhaust
system(s). These
include conventional rubber straps,
rubber rings, and rubber
blocks.
The installation of exhaust system supports is very
important,
as improperly installed supports can cause
annoying vibrations
which can be difficult to diagnose.
THREE WAY CATAL VTIC CONVERTER
The three way catalytic converter is an emission
control device added to the exhaust system to reduce
pollutants from the exhaust gas stream.
W CAUTION:
VI • The catalytic converter requires the use of
unleaded fuel only.
Periodic
maintenance of the exhaust system is not
required. If the vehicle is raised for other service, it is
advisable to check the condition of the complete
exhaust system.
A
dual bed monolith catalytic converter is used in
combination
with three way catalytic converter.
Catalytic Types:
Three
way (Reduction/Oxidation) catalyst
The catalyst coating on the three way (reduction)
converter contains
platinum and rhodium which
lowers the levels of oxide of nitrogen (NOx) as well as
hydrocarbons (HC) and carbon monoxide (Co).
GASKET
The gasket must be replaced whenever a new exhaust
pipe,
muffler or catalytic converter is installed.

•
"'Tl c3' -..J )> I "'
~ )
DASH
BOARD
DISPLA
V
*
*
*
*
ATF
WARNING
LAMP
CHECK
TRANS
LAMP
POWER DRIVE MODE LAMP WINTER DRIVE MODE LAMP
~----------------
SHIFT INDICATOR
LAMP
COMPENSATION
FOR
ENGINE
LOAD
AIR CONDITIONING SWITCH
TI
DRIVER'S
INPUT
liJ
MANUAL
SELECTOR
~
KICK-DOWN SWITCH
" ~
BRAKE
SWITCH
*
(AfT
SHIFT INDICATOR)
CONTROL
UNIT
---
' ---
I-------------,
il
PUSH BUTTON
FOR
NORMALJPOWER
DRIVE MODE
ON-BOARD DIAGNOSTIC
j4
.. ,
..
l__l--1 L_-$-L_g
ENGINE CONTROL
MODULE
(ECM)
_ IGNITION
CONTROL
I
MODULE
i
THROTTLE POSITION
SENSOR
ENGINE SPEED SENSOR
l
I
I -
ENGINE COOLANT TEMPERATU~,_.TCH
)
I +12 IGNITION
• •
TRANSMISSION
CONTROL MODULE
(TCM)
j
L I
BATTERY
)
--
~
'
5SOLENOID VALVES
il
-·----·
___.
u
PUSH BUTTON
FOR
WINTER DRIVE MODE
OTHERS
OVERDRIVE
OFF
SIGNAL
(CRUISE CONTROLLER)
ABS
SIGNAL
(ABS CONTROLLER)
f.-
n_
VEHICLE SPEED
SENSOR
f-
/
ATF TEMPERATURE SENSOR
L__ L__
[PRNDJ2L
I MODE SWITCH
-
m
.....
r-
)>
m
I
(")
..;=...
-t
)>
;::g 0
c:
2
-1
-
0
(")
s:
(")
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0
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en
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3:
-..;=... r-w 0 I !!!
)

AUTOMATIC TRANSMISSION (4l30-E) 7A-5
TRANSMISSION CONTROL MODULE (TCM)
ENGINE
ENGINE SPEED
ECM ENGINE
COOLANT
TEMPSW
;--J
---
SERIAL DATA
TORQUE
t MANAGEMENT TPS +
.L OUT
I -
4L30E
.J:
X a MODE SWA
Xb MODE SWB
Xc MODE SWC
Xg MODE SWG
A Ac OIL TEMP
Ad ANALOG GND
~~x OUTPUT SPEED HI
1 X1 OUTPUT SPEED LO
II A a TCCHI
Me SHIFT SOL. HI
~Md SHIFT SOL. 1-2/3-4
~Ma SHIFT SOL. 2-3
~Mb BAND APPLY SOL.
~Ab FORCE MOTOR HI
Ac FORCE MOTOR LO
ECM: Engine Control Module
TPS: Throttle Position Sensor
TCC: Torque Converter Clutch
ABS:
Anti-Lock Brake System
-
1
·-c
IGN BATT GND
h+ri A7 AS A4 C1 01
D12 VEHICLE
IGN
BRAKE SW ~ D14 D9 ~
DB AJC REQUEST /o---
CB BB POWER SW
=~
WINTERSW B6
C5 KICK DOWN SW C6 B5
-=
D7 IGN
D16 DIAG INIT. D6
~
D5 C10 CHECK TRANS LAMP
D4 TCM 89 POWER LAMP
A10 ATF WARNING LAMP ~
¥ 83 A11 WINTER LAMP
C14
A12
OD OFF SIGNAL CRUISE 812 84 CONTROLLER
811
C7 ABSSIGNAL ABS
810 CONTROLLER
C12
A2
A3
AS
C15
C16
Fig. 7A-3

7A-6 AUTOMATIC TRANSMISSION (4L30-E)
CONTROL SYSTEM DIAGRAM
L1J ~ (!) z L1J
I
I
lr
t:··
~ .. I I
I
I
AUTOMATIC TRANSMISSION ASSEMBLY
O.:a: :Eo LLJ(J) t-z --' L1J oVl
ENGINE COOLANT TEMPERATURE
ffio ~---a:O wz >LLJ z--' oo uCJ> w::C :::>u at-a:=> ~d
0 0 z ... w, --'"' o-.. (J)N t-.!-u.. J: CJ)
IGNITION
CONTROL .
MODULE
~==PO=W==ER==M=O=D=E=L=A=M=P~r.-------
r-------CHECK TRANS. LAMP
~=W=IN=T=E=R=M=O=D=E=LA=M=P~~--J---
::c u L1J a: 1-:.:: ::c <( :::> <( u L1J --' a: 1-(!) u al :::> >-L1J L1J 0 --' 1-~ z u a: :5 <( ~ ~ --' al Cl.
Cl. L1J i=
i= L1J ~ z :.:: --' --' <( L1J :5 :::> :::> a: z Cl. ::!: ::!: al 0
0 a: L1J 0 >-0 > --'o --' z (l._ 1-<( L1J Cl.Q 0 > __,..., "' 0--' L1J 1-zo u :::> u.. <(Vl a: z J: 0 <( al u.. ::!: CJ)
SHIFT
CONTROL
BAND APPLY CONTROL
TORQUE CONVERTER CLUTCH CONTROL
LINE PRESSURE CONTROL
SAFETY MODE
ON-BOARD DIAGNOSTIC
SYSTEM
TORQUE MANAGEMENT
ATF WARNING CONTROL
r-ABS CONTROL
L--A-T_F_w_A_R_N_I_N_G_L_A_M_P_...Jr---_l 1---------------'
0 L1J "'a: Bio wVl __,z uw J:Vl L1J >
POWER c): TRANSMIT
.... : OIL PRESSURE
CONTROL
MECHANICAL
...• : SIGNAL
LLJJ: ou ELECTRONIC ot:: -•: ::!:~ SIGNAL
KICK DOWN SWITCH
BRAKE SWITCH
POWER MODE SWITCH
WINTER MODE SWITCH
AIR CONDITIONING
SWITCH
ABS
SIGNAL (ASS CONTROLLER)
ABS: Anti-Lock Brake System
Fig. 7A-4
..

AUTOMATIC TRANSMISSION (4L30-E) 7 A-11
FUNCTIONS OF INPUT /OUTPUT COMPONENTS
Components Function
Speed sensor
Senses rotation
of output shaft and feeds the data to Transmission
(fixed
to transmission (T/M)) Control Module (TCM)
Throttle Senses the extent of throttle valve opening and the speed of the throttle
position sensor (TPS) valve lever motion to open the valve and feeds the data to TCM (fed to
(fixed to engine)
Engine Control Module (ECM) also)
I
Brake Switch (SW) Senses whether the driver has pressed the brake pedal or not and feeds
N (fixed
to brake pedal) the
information to TCM
p Kick-down SW (fixed to Senses whether the driver has pushed the accelerator pedal fully or not
u accelerator pedal) and feeds the information to TCM
T Mode
SW (fixed to T/M) Senses the select lever position and feeds the information to TCM
s Power drive SW Senses whether the driver has selected the power mode and feeds the
I (fixed to front console) information to TCM
G T/M
oil temp. sensor
Senses the T/M oil temperature and feeds the data to TCM
N Engine
coolant Senses the engine cooling water temperature and feeds the data to TCM
A temperature
SW (feeds the signal from ECM)
L
Engine speed
signal Feeds the signals monitoring engine speed to TCM from Ignition Control
Module
(fed to ECM also)
Air conditioning Senses whether the air conditioner has been switched on or not and
information feeds the information
to TCM
On-board diagnostic
input By monitoring the Ground (GND), the location of failure is shown on the
T/M
monitor lamp ("CHECK TRANS") by flashing the diagnostic trouble
code
Winter switch
Senses whether the driver has selected the winter mode, and feeds the
(fixed
to front console) information to TCM
Cruise
controller Downshift takes place when Overdrive OFF signal is received from auto
(Overdrive
OFF signal) cruise control unit
Shift
solenoid Selects shift point and gear position suited to the vehicle running con-s 1-2/3-4, 2-3
dition on the basis of TCM output 0 Band apply solenoid
Controls oil flow suited to the vehicle running condition on the basis of L
E TCM output
0 N
Torque
Converter Controls clutch engagement/disengagement suited to the vehicle
u 0 Clutch solenoid running condition on the basis of TCM output
T I Force motor Adjusts the oil pump delivery pressure to line pressure suited to the p D
(Pressure regulator vehicle running condition on the basis of TCM output u valve) T
Power drive mode lamp
Informs the driver whether the vehicle is in power mode or not
s Winter drive mode lamp Informs the driver whether the vehicle is in winter mode or not
I T/M monitor lamp Informs the driver of failure in the system. It also displays the self diagnosis
G
("CHECK TRANS") code.
N Data Link Connector
(DLC) When connected with TECH 1 or tester, can communicate the data for A
L function
check, etc. (fed to ECM also). When TECH 1 is not connected, can
communicate the
signal for torque management with ECM.
Self-diagnosis connector
When short-circuited with the bipolar connector, the T/M monitor lamp
displays
a failure by code.
ATF warning
lamp Lights when ATF oil temperature rises.
ABS signal When the select lever is at "Reverse" or "L" range, sends a signal to the
ABS controller as one of the ABS control conditions.

AUTOMATIC TRANSMISSION (4l30-E) 7A-19
PRELIMINARY INSPECTION CHART
Does symptom reflect
NORMAL OPERATIONS
OF 1994 -95 4L30·E
TRANSMISSION?
(See p.age-1-Ac13)
YES
Check CHART3: TRANSMISSION AND TCM IDENTIFICATION on page-~n.
Check TRANSMISSION FLUID LEVEL and CONDITION. See--page"'7A'•2'0.
Check manual linkage. TCM:
Transmission Control Module
Hydraulic system appears OK!
Are any DTC's stored in TCM?
NO
Refer to MANUAL LINKAGE in this manual.
See~.
Ll_v_e_rify_e_n_g_in_e..:.p_e~rf_or_m_a_n_c_e. ___ l--------1•~1 Refer to Engine Seeticm.
Road
test vehicle to verify concern l----------;..f~s~e;;e-;:ga;;;:;:ge~7.A:o.~2i2f;fo;;r~TiE:SsTTDD~RmlvliiNNiGG~.l
UCHECK TRANS"
flashing >--Y-ES ________ ~ See CHECK TRANS INDICATOR
CHART
on page 7A-23.
Any
Trouble Codes stored by TCM?
YES
See
MECHANICAL/HYDRAULIC DIAGNOSIS.~.
See ELECTRONIC DIAGNOSIS. ~r tliis nusnllal on-JH!ge 7A 45.