1995 ISUZU TROOPER Workshop Manual

AUTOMATIC TRANSMISSION (4L30-E) 7A-113
DIAGNOSTIC TROUBLE CODE (DTC) 42
SOLENOID 2-3 SHORT TO PLUS
• Ignition switch OFF.
• Disconnect Transmission Control Module (TCM)
connectors C-90 and C-91.
• Connect ohmmeter between connector C-90 terminals A3 and A7 (TCM ignition) then between A3
and A4 (TCM battery) then between A3 and C12.
IF: Short circuit:
• Check for faulty connector or wiring between terminal A3 and the shorted terminal.
•
Repair.
• Connect ohmmeter between A3 and A2 then between
A3 and A9.
IF: Short circuit:
The
problem is intermittent. GOTO INTERMmENT CONDITIONS.

7A-114 AUTOMATIC TRANSMISSION (4l30-E)
DIAGNOSTIC TROUBLE CODE (DTC) 43
TCC HIGH SHORT TO GROUND
This DTC does NOT flash the CHECK TRANS
indicator and does NOT set the BACKUP MODE.
Circuit Description:
• The Torque Converter Clutch (TCC) solenoid is a
simple ON/OFF solenoid connected to the
adapter case
valve body. When the solenoid is
energized
by the Transmission Control Module
(TCM), it opens a fluid port. When the port is
open,
line pressure actuates the converter clutch
control valve
which engages the torque converter
clutch by exhausting the fluid. The TCM engages
the
torque converter clutch only when all of the
following conditions exist:
G) The transmission is at operating temperature.
@ The brake pedal is released.
® The transmission is operating in second, third
or fourth gear.
® The engine is warm (more than 70°C).
@ The shift pattern requests TCC apply.
® Shift finished.
(f) No malfunction which will disable the TCC:
DTC33, DTC55 (only short to ground).
• The solenoid is activated by a 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 TCM
that acts as a switch between the solenoid and
the supply voltage. The High side of the TCC
solenoid is used to turn the TCC ON or OFF
because the Low side is permanently connected
to the ground of the transmission. In BACKUP
MODE or when ignition OFF the TCC High Side is
turned OFIF.
• The TCM continually monitors the solenoid
connection of to its High Side Driver for either
low or high voltage.
• There is only one test of the HSD for TCC: when
the engine is cranked and the TCC is turned ON.
Diagnostic .Aids:
• This diagnostic is an electrical test done by the
TCM.
• Detection conditions:
G) The solenoid High side connected to TCM
terminal C7 is shorted to ground.
@ The condition needs to be present for 0.07
seconds after ignition switch ON.
•
Action after the detection time: TCC is turned
OFF.
• Recovery eonditions: To recover, do an IGNITION
CYCLE.
r - - --, C-S1 BRN/BLU H-10 TORQUE I >-----__:_---<1 ~ ~'---------4-(A~) \1, M-6
g~~i~~TER I C7 II --1-- -- ---, AUTOMATIC
SOLENOID 1 TRANSMISSION
I
I
CONTROL
I I
I {I? GROUND I I C1 )
l---~ 01
TRANSMISSION CONTROL
MODULE (TCM)
I
: II
I
TORQUE CONVE:RTER CLUTCH
SOLEt\A0
I I H-11 - -~· - - - - - - -BLKJORN ~
9
-=-,5 BLK/BLU (
1
•

AUTOMATIC TRANSMISSION (4L30•E) 7A-115
IF you have a SCAN TOOL: TECH1?
$
DIAGNOSTIC TROUBLE CODE (OTC) 43
TCC HIGH SHORT TO GROUND
$
• Install scan tool: TECH1 GOTHROUGH TECH1 CONNECTION . I Without TECH1 you can not do preliminary test.
While driving the car in 2nd, 3rd or 4th gear check if the TCC is slipping or not when the TCC solenoid is commanded ON by the TCM.
Push FO: DATA LIST:
I Read TCC state and SLIP value.
CASE: SLIP
> 20 RPM with I CASE: DTC 33
I TCC =ON GOTO DTC33.
This means that the TCC valve is stuck OFF or the TCC solenoid connections are shorted to ground.
SHORT TO GROUND?
• Ignition switch OFF. Engine OFF .
• Disconnect Transmission Control Module ITCM) connectors C-90 and C-91.
• Connect a ohmmeter between connector C-91 terminal C7 and car ground or with TCM ground terminal C1.
IF: Short circuit:
~ $
The TCC is shorted to ground. I The problem is intermittent.
I GOTO INTERMITTENT CONDITIONS.
• Check wiring between terminal C7 and ground.
• Repair .
TCC: Torque Converter Clutch
TCM: Transmission Control Module
I

7A-116 AUTOMATIC TRANSMISSION (4L30-E)
DIAGNOSTIC TROUBLE CODE (DTC) 44
BAND APPLY SOLENOID SHORT TO PLUS
This DTC flashes the CHECK TRANS indicator and
sets the BACKUP
MODE.
Circuit Description:
• The band apply solenoid is a normally open
solenoid which controls the flow of fluid for brake
band
application. The Transmission Control
Module (TCM) uses Pulse Width Modulation
(PWM) and changes the duty cycle to control the
solenoid. The TCM turns the solenoid ON
(energized) and OFF (de-energized) 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 "modulating" the
pulse width, the solenoid output pressure is
changed.
Since the solenoid is normally closed,
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 a 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 TCM
that acts as a switch between the solenoids and
the
supply voltage. The High side of the solenoid
is permanently supplied with voltage, except in
BACKUP
MODE or when ignition is OFF the HSD
H-7
is turned OFF.
• The TCM continually monitors the solenoid
connection to its Low Side Driver (LSD) for either
low or high voltage. The LSD is a circuit of the
TCM
that acts as a switch between the solenoid
and ground. When the solenoid is commanded
ON the TCM is switching the solenoid to ground.
• There are two tests of the LSD: when the engine
is cranked (DTC82) and
when the ignition is
turned
ON (DTC44).
• When the ignition is turned ON, and before the
engine is cranked, the TCM activates the
shift
solenoids (1-2/3-4, 2-3 and Band) to check for
short circuits or open circuits. To do so the gear
is set
to 4th, 3rd, 1st, 1st with band apply, 4th
with no HSD. Each one of the 5 tests requires
0.15 second. If the engine is cranked before the
end
of all tests, the remaining tests are not done.
Diagnostic Aids:
• This diagnostic is an electrical test done by the
TCM.
• Detection conditions:
CD The solenoid Low side connected to TCM
termin.al A9 is shorted to voltage.
@ The test is only done when ignition is ON.
@ Engine Speed < 480 RPM (not cranked) and
Output
Speed = 0 RPM.
@ The condition needs to be present for 0.15 to
1.18 second after ignition switch ON.
•
Action after the detection time: BACKUP MODE.
•
Recovery conditions: To recover, do an IGNITION
CYCLE.
,... BATTERY-, C-90
I INPUT I? A4 GRN/WHT ·~-----BATTERY
( 4
I IGNITION I ? I INPUT A7 II
I { I? AS I GROUND I ? A3
I
)
I A2
I I
I
I
I I
I I
I
I
I I
I SHIFT& I
I BANDAPPLY C-91 SOLENOID I 1 _:oNTROL _ 1
TRANSMISSION
CONTROL MODULE (TCMI
C12
RED/GRN
BRN/YEL
BRN/BLK
BRN/RED
BRN/WHT
H-42 •--::------ECM MAIN RELAY )) 8 H-10
«--------3-(D--,I'l----- --'~L -,,,l M-7
( 12
2:j
16 r-- -r ----r ----
1-- --
AUTOMATIC I
I TRANSMISSION
: H::Q]:;& : I OLE SOlENOID I
I I
I I
1-213-4 2-:
-II
SHIFT
II
s SOLE NOlO s
-"--------_______ .J
H-10 ( 10
•