1995 ISUZU TROOPER Workshop Manual

AUTOMATIC TRANSMISSION (4L30-E) 7A-129
DIAGNOSTIC TROUBLE CODE (DTC) 55
BRAKE SWITCH SHORT TO GROUND OR OPEN
• Install scan tool GOTHROUGH TECH1 CONNECTION.
• Ignition switch ON. Engine ON.
• Select FO: DATA LIST: uBRAKE SWITCW.
•
Apply brake. IF: Display is uACTIVE":
The problem is
intermittent.
GOTO
INTERMITTENT
CONDITIONS. •
Check the short circuit to ground or open.
• Repair.

7A-130 AUTOMATIC TRANSMISSION (4l30-E)
DIAGNOSTIC
TROUBLE CODE (DTC)·56
BRAKE SWITCH SHORT TO PLUS
This DTC does NOT flash the CHECK TRANS
indicator and does
NOT set the BACKUP MODE.
Circuit Description:
• The brake switch is a switch on the brake pedal
that is used to provide the information: brakes
are
applied. This is used by different features:
cruise
control, stop light and Transmission
Control Module (TCM).
•
The TCM uses the information (brakes applied)
mainly to release the Torque Converter Clutch
(TCC).
• The brake switch input is constantly connected to
battery when the pedal is pressed. TCM terminal
D9 is connected to Voltage.
•
The brake switch input is opened when the pedal
is released. TCM terminal D9 is grounded.
r----
IBRAKESW I INPUT I
I I C-91 GRN!YEL H-7 I lf~D-9--~~~------~~
I II I
I GROUND { 1 ?c1 II I >o1
I I
I I
.._ ___ J
TRANSMISSION
CONTROL
MODULE (TCM)
H-11
BLK!ORN sq
BLK!BLU ~
1
Diagnostic Aids:
• This Diagnostic is not an electrical test done by
the TCM but a test between different information
("logic test").
•
Detection conditions:
CD Brake seen as released during a deceleration
from more than 60 Km/h to less than 10 Km/h
within 6 seconds.
® Before this deceleration the car vehicle speed
was
higher than 60 Km/h during at least 6
seconds.
@ No Malfunction: Output Speed (DTC11).
Downshift Protection (DTC62).
@ The conditions need to be present for at least
5 times; during an ignition cycle.
•
Action atte~r the detection time: No action but, as
the brake is seen as released, the TCC is applied
even when the brake is applied.
•
Recovery conditions: To recover, brake has to be
released.
BATTERY(+)
,.------, d / '
GRN/YEL I /~;3 I ~-~3' I
~4 I I 1 I
STOP LIGHT <0---.Jr ~~l/ \3 1 ___ , 2/
' / ' BRAKE SW ,. .......... -----.......
CRUISE CONTROL UNIT(8) RELAY CRUISE MAIN (4)
BATTERY(+)
~~~R~s:_ d
·:.:-: ---~~~-14
2 L--_I 1
STOP LIGHT SW
•

AUTOMATIC TRANSMISSION (4L30-E) 7A-131
DIAGNOSTIC TROUBLE CODE (DTC) 56
BRAKE SWITCH SHORT TO PLUS
• Install scan tool GOTH ROUGH TECH1 CONNECTION.
• Ignition switch ON. Engine ON.
• Select FO: DATA LIST: uBRAKE SWITCH".
•
Do not touch brake. IF: Display is uACTIVEu:
•
Check the short circuit
to voltage.
•
Repair. The
problem is
intermittent. GOTO
INTERMITTENT CONDITIONS.

7A-132 AUTOMATIC TRANSMISSION (4L30-E)
DIAGNOSTIC TROUBLE CODE (DTC) 61
GEAR ERROR
This DTC flashes the CHECK TRANS indicator and
sets the BACKUP MODE.
Circuit Description:
• The Transmission Control Module (TCM) is
calculating 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. Then the transmission
should not slip more than a given value when
there is no shift.
Diagnostic Aids:
• This Diagnostic is not an electrical test done by
the TCM but a test between different information
("logic test").
• Detection conditions:
CD Engine Speed > 3500 RPM
@ Using the ratio of the current gear the
Converter Slippage is calculated based upon
the engine speed and the output speed. This
slippage must be more than:
528
RPM in 4th gear
536 RPM in 3rd gear
556 RPM in 2nd gear
595 RPM in 1st gear
@ No malfunction: Engine Speed (DTC13).
Output Speed (DTC11 ). Downshift Protection
(DTC62).
@ The last change of shift solenoid was more
than 3 seconds ago.
® The conditions need to be present for at least
5.5 seconds.
• Action after the detection time: BACKUP MODE.
•
Recovery conditions: To recover, do an IGNITION
CYCLE.
NOTE:
The TCC slip data is a calculated value, and not an
accurate one.
This value should be used to see if the TCC is
engaged or not.
•

AUTOMATIC TRANSMISSION (4L30-E) 7 A-133
DIAGNOSTIC TROUBLE CODE (DTC) 61
GEAR ERROR
IF the car has been in BACKUP MODE when the problem occurred:
IF there is another DTC which causes Backup Mode (DTC20, DTC21, DTC22, DTC23, DTC25, DTC26, DTC31,
DTC32, DTC34, DTC35, DTC36, DTC37, DTC41, DTC42,
DTC44, DTC46, DTC54, DTC63, DTC82):
Verify this other diagnosis first (because,
in backup mode the
DTC61 is detected in Manual 2 at high engine speed though there is no problem). GOTO next DTCs.
Do a test drive to reproduce the problem using the DRIVER
INFORMATION.
IF reproduced without Backup
Mode:
GOTO TCM MEM-CAL
REPLACEMENT.

7A-134 AUTOMATIC TRANSMISSION (4L30-E)
DIAGNOSTIC TROUBLE CODE (DTC) 62
DOWNSHIFT PROTECTION
This DTC flashes the CHECK TRANS indicator and
sets the
BACKUP MODE.
Circuit Description:
• The output speed information is used to
determine if the transmission has to upshift or
downshift.
• If this information suddenly changes due to an
open circuit or some electrical interference the
transmission
would downshift.
• To avoid this the Transmission Control Module
(TCM) is constantly checking the variations of the
Output Speed. If this variation is too great (too
much decrease
or increase) DTC62 is set. This
variation is taken into
amount only when the
output speed is more than : 90 KPH.
• The transmission output speed sensor provides
information on vehicle speed to the TCM. The
speed sensor circuit consists
of a magnetic
induction
type sensor. The sensor is mounted
above a target wheel pressed on the output shaft
in the transmission extension. As the
output
shaft turns, the target wheel teeth induce a
TRANSMISSION SPEED SENSOR SHIELDS
variable voltage in the magnetic pickup. This
alternating current (AC) signal is provided to the
TCM. The
voltage increases with the speed of
the wheel but this is not used to define the speed
of the vehicle. As the vehicle moves faster, the
signal alternates faster between positive and
negative
voltages. The Output speed information
is proportiional to the frequency of the signal.
Diagnostic Aids:
• This Diagnostic is not an electrical test done by
the TCM but a test between different information
("logic test").
• Detection conditions:
G) Variation of Output Speed >16 KPH/0.025s.
@ Ignition ON more than 5 seconds.
@ Mode Switch not in P, N or R.
@ Last Output Speed > 90 KPH.
@ The conditions need to be present for at least
0.1 second.
• Action after the detection time: BACKUP MODE.
•
Recovery Gonditions: To recover, do an IGNITION
CYCLE.
- - - -C-90 / " I ,---:-"'\. '-. ~---+I WHT I I I I ~-10 I 'I I 'I M-1
5 r - - - - - - -TRANSMISSION ) f I SPEED SENSOR I . I f A 12 I I I I ~ I I I I
I II I I I I I I I I I
I II I I I I 1 I I
~~~~rie II I Ill I I
IINPUT II I I I I
1 1 1 I l I I I I -? ORN I I < I I
I l: ):~~ BLK \~ __ ~~ __ ~
I GROUNO I C-91 BLK/ORN H-11
I I I C1 BLK/BLU ~ 9_ I ____ I D1
TRANSMISSION
CONTROL MODULE (TCM)
2 I I (EXTENSION)
: : .·(C},h.·.. ,.·, .. ·.,· .. : HOUSING
II II ·<;',~ . I
I I . 'I ' . . I
I I I
) I> 1 ________ I
•