Isuzu D-Max / Isuzu Rodeo (TFR/TFS). Manual - part 648

7A1–92 AUTOMATIC TRANSMISSION (4L30-E)

DIAGNOSTIC TROUBLE CODE (DTC) 33

TCC HIGH SHORT TO PLUS OR OPEN

(CONTINUED)

CONTINUED FROM
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A

TCC: Torque Converter Clutch
TCM: Transmission Control Module

YES

YES

NO

NO

YES

NO

•

Wire between connector C-95 terminal C7 and
adapter case connector is open or shorted to
another wire.

•

Repair. 

•

Wire between adapter case connector and
solenoid is open.

•

Or wire between transmission (ground) and
solenoid is open.

•

Repair. 

•

Disconnect solenoid connector.

•

Connect ohmmeter between the two solenoid
terminals.

IF: Display is between 17.5 and 18.5 ohms.

•

Disconnect transmission adapter case connector M-6.

•

Connect ohmmeter between terminal 4(A) of female half of
connector and transmission which is used as ground.

IF: Display between 17.5 and 18.5 ohms:

GOTO TCM MEM-CAL
REPLACEMENT.

Replace torque converter
clutch solenoid.

OPEN?

•

Ignition switch OFF. 

•

Disconnect TCM connector C-95 and C-96.

•

Connect ohmmeter between connector C-95 terminal
C7 and C1 (TCM ground).

IF: Display is between 17.5 and 18.5 ohms.

AUTOMATIC TRANSMISSION (4L30-E) 7A1–93

MEMO

7A1–94 AUTOMATIC TRANSMISSION (4L30-E)

DIAGNOSTIC TROUBLE CODE (DTC) 34

BAND APPLY SOLENOID SHORT TO GROUND OR OPEN

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

is turned OFF.

•

The TCM continually monitors the splenoid
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 (DTC34).

•

When the ignition is turned ON, and before the
engine is cranked, the TCM activates the shift
solenoids (A, B 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:
1 The solenoid Low side connected to TCM

terminal A9 is shorted to ground or open.

2 The test is only done when ignition is ON.
3 Engine Speed <480 RPM (not cranked) and

Output Speed = 0 RPM.

4 The condition needs to be present for 0.15 to

0.75 second after ignition switch ON.

•

Action after the detection time: BACKUP MODE.

•

Recovery conditions: To recover, do an IGNITION
CYCLE.

BAND
APPLY
SOLENOID
CONTROL

GROUND

TRANSMISSION
CONTROL
MODULE (TCM)

SHIFT
SOLENOID
A

SHIFT
SOLENOID
B

BAND 
APPLY
SOLENOID

AUTOMATIC
TRANSMISSION

M-7

M-7

2(B)

4(C)

C-96

H-23

14

H-23

16

BRN/WHT

BRN/WHT

YEL/BLK

BLK

BLK

BLK

7

H-25

C1(1)

D1(17)

A9(9)

C-95

C12(12)

GROUND

YEL/BLK

D07LW014

AUTOMATIC TRANSMISSION (4L30-E) 7A1–95

•

Ignition switch off.

•

Disconnect Transmission Control Module (TCM)
connector C-95 and C-96

•

Connect ohmmeter between connector C-95 terminal
C12 and connector C-96 terminal A9.

IF: Display is approx. 10 ohms:

•

Connect ohmmeter between connector C-96 terminal
A9 and connector C-95 terminal C1 (TCM ground)

IF: Short circuit:

•

Check for an open circuit between connector C-96
terminal A9 and connector C-95 terminal C12.

IF: Wiring problem?

•

Disconnect band apply solenoid connector.
IF: Ohmmeter displays approx. 10 ohms on
the band apply solenoid terminals:

The problem is intermittent.
GOTO INTERMITTENT
CONDITIONS.

The problem is intermittent.
GOTO INTERMITTENT
CONDITIONS.

YES

YES

NO

YES

NO

DIAGNOSTIC TROUBLE CODE (DTC) 34

BAND APPLY SOLENOID SHORT TO GROUND OR OPEN

•

Check for faulty
connector or wiring
between terminal A9
and ground.

•

Repair.

Repair. 

Replace the band apply solenoid.

NO

YES

NO