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Isuzu Amigo / Axiom / Trooper / Rodeo / VehiCross. Manual - part 427

7A1–18 TRANSMISSION CONTROL SYSTEM (4L30–E)

Transmission Data

Tech 2 string

Unit

Engine running at idle

Ignition Voltage

12.8

∼

14.1 V

Engine Speed

RPM

750

∼

900 RPM

Vehicle Speed

km/h, MPH

0 MPH

AT Output Speed (Automatic Transmission)

RPM

0 RPM

AT Input Speed Ratio (Automatic Transmission)

0.0

Throttle Position

0 %

AT Oil Temperature (Automatic Transmission)

∼

C (158

∼

176

Transmission Temperature

∼

110

C (167

∼

230

AT Oil Temperature Lamp (Automatic Transmission)

On/Off

Off

AT Oil Life Monitor (Automatic Transmission)

100 %

AT Oil Life Lamp (Automatic Transmission)

On/Off

(Not used)

Commanded Gear

Current Gear

Mode Switch A

Inactive/Active

Active

Mode Switch B

Inactive/Active

Inactive

Mode Switch C

Inactive/Active

Inactive

Mode Switch G

Inactive/Active

Active

Selector Position

Park

1–2 Shift Solenoid A

On/Off

Off

2–3 Shift Solenoid B

On/Off

Solenoid Brake Band

On/Off

Off

TCC Slip Speed

RPM

750

∼

900 RPM

TCC Solenoid

On/Off

Off

TCC Duty Cycle

0 %

PCS Current (Pressure Control Solenoid)

approx. 1.0 A

PCS Duty Cycle (Pressure Control Solenoid)

approx. 45

∼

60 %

Desired PCS Pressure (Pressure Control Solenoid)

kPa

∼

52 kPa

Shift Pressure

kPa

∼

52 kPa

Brake Switch

On/Off

Winter Switch

On/Off

Off

Winter Drive Lamp

On/Off

Off

Power Switch

Normal

Power Drive Lamp

Off/On

Off

Emergency Mode

Inactive/Active

Inactive

ABS Status

On/Off

(Not used)

TRANSMISSION CONTROL SYSTEM (4L30–E)

7A1–19

OBD II Diagnostic Management System

Powertrain Control Module (PCM) Location

825R100018

826RY002

Class 2 Serial Data Bus
OBD II technology requires a much more sophisticated
PCM than does OBD I technology. The OBD II PCM
diagnostic management system not only monitors
systems and components that can impact emissions, but
they also run active tests on these systems and
components. The decision making functions of OBD II
PCMs have also greatly increased. To accommodate this
expansion in diagnostic complexity, Isuzu engineers have
designed the Class 2 serial data bus, which meets SAE
J1850 recommended practice for serial data.
“Serial Data” refers to information which is transferred in a
linear fashion – over a single line, one bit at a time. A “Data
Bus” is an electronic pathway through which serial data
travels.

AXIOM previously used a 5 volt data bus called UART,
which is an acronym for “Universal Asynchronous
Receive and Transmit”. When neither the vehicle’s
control module nor the diagnostic tool, such as a Tech 2,
are “talking,” the voltage level of the bus at rest is 5 volts.
The two computers talk to each other at a rate of 8,192
bits per second, by toggling or switching the voltage on
the data bus from 5 volts to ground.
Class 2 data, which is used on OBD II vehicles, is quite
different. Data is transferred at a rate of 10.4 kilobits per
second, and the voltage is toggled between zero and 7
volts.

7A1–20 TRANSMISSION CONTROL SYSTEM (4L30–E)

C07RT006

Class 2 data is also pulse width modulated. Each bit of
information can have one of two lengths: long or short. On
the other hand, UART data bits come in only one length
(short). The pulse width modulation of Class 2 data allows
better utilization of the data line.
The message carried on Class 2 data streams are also
prioritized. This means that if two devices try to
communicate on the data line at the same time, only the
higher priority message will continue. The device with the
lower priority message must wait.

NOTE: The Class 2 data wire is always terminal 2 of the
new 16–terminal Data Link Connector (DLC).

16 – Terminal Data Link Connector (DLC)

OBD II standardizes Data Link Connector (DLC)
configurations. The DLC, formerly referred to as the
ALDL, will be a 16–terminal connector found on the lower
left side of the driver’s side instrument panel. All
manufacturers must conform to this 16–terminal
standard.

826R200011

TRANSMISSION CONTROL SYSTEM (4L30–E)

7A1–21

810RT022

PIN 1 –

DIAG. SW

PIN 2 –

J1850 Bus + L line on 2–wire systems, or
single wire (Class 2)

PIN 3 –

Active suspension diagnostic enable

PIN 4 –

Chassis ground pin

PIN 5 –

Signal ground pin

PIN 6 –

(Not used)

PIN 7 –

TOD diagnostic enable

PIN 8 –

TOD diagnostic enable

PIN 9 –

Primary UART

PIN 10 –

(Not used)

PIN 11 –

(Not used)

PIN 12 –

ABS diagnostic or CCM diagnostic enable

PIN 13 –

SIR diagnostic enable

PIN 14 –

(Not used)

PIN 15 –

(Not used)

PIN 16 –

Battery power from vehicle unswitched (4
AMP MAX.)

Malfunction Indicator Lamp (MIL)

The Malfunction Indicator Lamp (MIL) looks the same as
the MIL you are already familiar with (“CHECK ENGINE”
lamp). However, OBD II requires for it illuminate under a
strict set of guidelines. Basically, the MIL is turned on
when the PCM detects a DTC that will impact the vehicle’s
emissions.
The MIL is under the control of the Diagnostic Executive.
The MIL will be turned on if a component or system which
has an impact on vehicle emissions indicates a
malfunction or fails to pass an emissions–related
diagnostic test. It will stay on until the system or
component passes the same test, for three consecutive
trips, with no emissions–related faults.

DTC Types

Each DTC is directly related to a diagnostic test. The
Diagnostic Management System sets DTC based on the
failure of the tests during a trip or trips. Certain tests must
fail two (2) consecutive trips before the DTC is set. The
following are the four (4) types of DTCs and the
characteristics of those codes:

Type A

Emissions related

Requests illumination of the MIL of the first trip with a
fail

Stores a History DTC on the first trip with a fail

Stores a Freeze Frame (if empty) (DTC Information
for 6VE1 engine)

Stores a Fail Record

Updates the Fail Record each time the diagnostic
test fails

Type B

Emissions related

“Armed” after one (1) trip with a fail

“Disarmed” after one (1) trip with a pass

Requests illumination of the MIL on the

second

consecutive trip with a fail

Stores a History DTC on the second consecutive trip
with a fail (The DTC will be armed after the first fail)

Stores a Freeze Frame on the second consecutive
trip with a fail (if empty) (DTC Information for 6VE1
engine)

Stores a Fail Record when the first test fails (not
dependent on

consecutive trip fails)

Updates the Fail Record each time the diagnostic
test fails

(Some special conditions apply to misfire and fuel trim
DTCs)

Type C (if the vehicle is so equipped)

Non-Emissions related

Requests illumination of the Service Lamp or the
service message on the Drive Information Center
(DIC) on the

first trip with a fail

Stores a History DTC on the

first trip with a fail

Does not store a Freeze Frame

Stores Fail Record when test fails

Updates the Fail Record each time the diagnostic
test fails

Type D

Non-Emissions related

Not request illumination of any lamp

Stores a History DTC on the

first trip with a fail

Does not store a Freeze Frame

Stores Fail Record when test fails

Updates the Fail Record each time the diagnostic
test fails

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