Isuzu D-Max / Isuzu Rodeo (TFR/TFS). Manual - part 657

7A1–128 AUTOMATIC TRANSMISSION (4L30-E)

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A

DIAGNOSTIC TROUBLE CODE (DTC) 62

DOWNSHIFT PROTECTION

(CONTINUED)

HINT:

•

The wire between connector C-96 terminal B12 and
speed sensor connector M-15 terminal 2 can be
shorted to ground or open without creating a
problem because the TCM B12 pin is connected to
the TCM ground iternally and the signal is detected
only on the A12 input.

•

Check wire for a short to ground between terminal
A12 and sensor connector M-15 terminal 1.

IF: Display indicates a short circuit:

YES

Repair.

NO

•

Connect voltmeter between connector C-96
terminal A12 and ground connector C-95
terminal C1.

•

Ignition switch ON.

IF: Display indicates approximately 0 volt:

YES

NO

•

Check for faulty TCM
connectors. If OK GOTO
TCM MEM-CAL
REPLACEMENT.

•

Check wire for a short
to voltage between
terminal A12 and speed
sensor connector M-15.

AUTOMATIC TRANSMISSION (4L30-E) 7A1–129

DIAGNOSTIC TROUBLE CODE (DTC) 63

EPROM CSUM FAILURE

This DTC flashes the CHECK TRANS indicator and
sets the BACKUP MODE.

Circuit Description:

•

The Erasable Programmable Read Only Memory
(EPROM) is an electronic circuit that contains the
commands that control the Transmission Control
Module (TCM).

•

The EPROM content is checked automatically
approx. each second by the TCM. This is called
Check Sum (CSUM) calculation. If this CSUM is
false this means that one command is altered.

•

This can be due to a circuit failure or a bad
contact between the EPROM and the TCM and
the DTC63 will be set.

•

If all EPROM connections are bad, the TCM does
not work. The CSUM can not be calculated and
detected. Nothing works, not even the CHECK
TRANS indicator.

Diagnostic Aids:

•

This Diagnostic is not an electrical test done by
the TCM but a test between different information
(“logic test”).

•

Detection conditions:
1 Bad EPROM Check Sum.
2 The condition needs to be present for at least

approx. 1 second.

•

Action after the detection time: BACKUP MODE.

•

Recovery conditions: To recover, do an IGNITION
CYCLE.

To Solve the Problem

•

Check the EPROM MEM-CAL connector.

•

If condition still exists, replace MEM-CAL.

7A1–130 AUTOMATIC TRANSMISSION (4L30-E)

DIAGNOSTIC TROUBLE CODE (DTC) 82

SHIFT OR BAND APPLY SOLENOIDS FAULTY DURING DRIVING

This DTC flashes the CHECK TRANS indicator and
sets the BACKUP MODE.

Circuit Description:

•

The shift solenoids are simple ON/OFF solenoids
located in the main case valve body. The
solenoids are normally closed or open-type.
Depending on gear the Transmission Control
Module (TCM) controls the solenoids to open or
close a fluid inlet port. When the port is open,
fluid pressure actuates the shift valve.

•

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 High
Side Driver is turned OFF.

•

The Low Side Driver (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.

The TCM continually monitors each solenoid
connection to its Low Side Driver and to its High
Side Driver for either low or high voltage.

•

DTC82 is activated when the Shift High Side
Driver or one of the Shift Low Side Drivers
senses a short circuit or open circuit when the
engine is cranked, then when the car is driven.
DTC82 can be set only when the TCM is
activating the solenoids in with the problem
circuit.

•

To know where the fault comes from, do
IGNITION CYCLE to use the TCM self-check of
solenoids when Engine is not cranked but
Ignition ON.

Diagnostic Aids:

•

This diagnostic is an electrical test done by the
TCM.

•

Detection conditions:
1 HSD or LSD is improperly ON.
2 The condition needs to be present for at least

0.15 second.

•

Action after the detection time: BACKUP MODE

•

Recovery conditions: To recover, do after
IGNITION CYCLE.

AUTOMATIC TRANSMISSION (4L30-E) 7A1–131

DIAGNOSTIC TROUBLE CODE (DTC) 82

SHIFT OR BAND APPLY SOLENOIDS FAULTY DURING DRIVING

This DTC is set when the car is driven (Engine ON) but
the diagnostic is not specific.
To correctly identify the problem, do an IGNITION
CYCLE.

If you have not already done an IGNITION CYCLE:

•

Turn ignition switch OFF. Turn ignition switch ON
and wait 3 seconds to have the specific diagnostic
done.

•

Then you can turn the engine ON or not.

Check on Scan Tool or Flashing Code what other DTC is
provided. It should be one of the following:
DTC31 or DTC32 or DTC34 or DTC36 or DTC41 or DTC42
or DTC44 or DTC46.

GOTO this DTC.