Opel Frontera UBS. Manual - part 2117

6E–41

ENGINE DRIVEABILITY AND EMISSIONS

If the MIL was set by either a fuel trim or misfire-related
DTC, additional requirements must be met. In addition to
the requirements stated in the previous paragraph, these
requirements are as follows:

The diagnostic tests that are passed must occur with
375 RPM of the RPM data stored at the time the last
test failed.

Plus or minus ten (10) percent of the engine load that
was stored at the time the last failed.

Similar engine temperature conditions (warmed up or
warming up ) as those stored at the time the last test
failed.

Meeting these requirements ensures that the fault which
turned on the MIL has been corrected.
The MIL (“Check Engine” lamp) is on the instrument
panel and has the following function:

It informs the driver that a fault affects vehicle emission
levels has occurred and that the vehicle should be
taken for service as soon as possible.

As a bulb and system check, the MIL will come “ON”
with the key “ON” and the engine not running. When
the engine is started, the MIL will turn “OFF.”

When the MIL remains “ON” while the engine is
running, or when a malfunction is suspected due to a
driveability or emissions problem, a Powertrain
On-Board Diagnostic (OBD ll) System Check must be
performed. The procedures for these checks are given
in On-Board Diagnostic (OBD) System Check. These
checks will expose faults which may not be detected if
other diagnostics are performed first.

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)

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)

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

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 (

Type D non-emissions related are not utilized

on certain vehicle applications).

Non-Emissions related

Dose 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

IMPORTANT:

Only four Fail Records can be stored.

Each Fail Record is for a different DTC. It is possible that
there will not be Fail Records for every DTC if multiple
DTCs are set.

Storing and Erasing Freeze Frame Data and Failure
Records
The data captured is called Freeze Frame data. The
Freeze Frame data is very similar to a single record of
operating conditions. Whenever the MIL is illuminated,
the corresponding record of operating conditions is
recorded to the Freeze Frame buffer.
Data from these faults take precedence over data
associated with any other fault. The Freeze Frame data
will not be erased unless the associated history DTC is
cleared.
Each time a diagnostic test reports a failure, the current
engine operating conditions are recorded in the

Failure

Records buffer. A subsequent failure will update the
recorded operating conditions. The following operating
conditions for the diagnostic test which failed

typically

include the following parameters:

Air Fuel Ratio

Air Flow Rate

Fuel Trim

Engine Speed

Engine Load

Engine Coolant Temperature

Vehicle Speed

TP Angle

MAP/BARO

Injector Base Pulse Width

Loop Status

6E–42

ENGINE DRIVEABILITY AND EMISSIONS

Intermittent Malfunction Indicator Lamp
In the case of an “intermittent” fault, the MIL (“Check
Engine” lamp) may illuminate and then (after three trips)
go “OFF”. However, the corresponding diagnostic trouble
code will be stored in the memory. When unexpected
diagnostic trouble codes appear, check for an intermittent
malfunction.
A diagnostic trouble code may reset. Consult the
“Diagnostic Aids” associated with the diagnostic trouble
code. A physical inspection of the applicable sub-system
most often will resolve the problem.

Data Link Connector (DLC)
The provision for communication with the control module
is the Data Link Connector (DLC). The DLC is used to
connect to Tech 2. Some common uses of Tech 2 are
listed below:

Identifying stored Diagnostic Trouble Codes (DTCs).

Clearing DTCs.

Performing output control tests.

Reading serial data.

TS24064

Verifying Vehicle Repair

Verification of vehicle repair will be more comprehensive
for vehicles with OBD system diagnostic. Following a
repair, the technician should perform the following steps:
1. Review and record the Fail Records and/or Freeze

Frame data for the DTC which has been diagnosed
(Freeze Frame data will only be stored for an A or B
type diagnostic and only if the MIL has been
requested).

2. Clear DTC(s).
3. Operate the vehicle within conditions noted in the Fail

Records and/or Freeze Frame data.

4. Monitor the DTC status information for the specific

DTC which has been diagnosed until the diagnostic
test associated with that DTC runs.

Following these steps are very important in verifying
repairs on OBD systems. Failure to follow these steps
could result in unnecessary repairs.

Reading Diagnostic Trouble Codes Using
A Tech 2

The procedure for reading diagnostic trouble code(s) is to
used a diagnostic Tech 2. When reading DTC(s), follow
instructions supplied by Tech 2 manufacturer.

Clearing Diagnostic Trouble Codes

IMPORTANT:

Do not clear DTCs unless directed to do

so by the service information provided for each diagnostic
procedure. When DTCs are cleared, the Freeze Frame
and Failure Record data which may help diagnose an
intermittent fault will also be erased from memory.
If the fault that caused the DTC to be stored into memory
has been corrected, the Diagnostic Executive will begin to
count the “warm-up” cycles with no further faults
detected, the DTC will automatically be cleared from the
PCM memory.
To clear Diagnostic Trouble Codes (DTCs), use the
diagnostic Tech 2 “clear DTCs”. When clearing DTCs
follow instructions supplied by the tool manufacturer.
When Tech 2 is not available, DTCs can also be cleared
by disconnecting

one of the following sources for at least

thirty (30) seconds.

NOTE: To prevent system damage, the ignition key must
be “OFF” when disconnecting or reconnecting battery
power.

The power source to the control module. Examples:
fuse, pigtail at battery PCM connectors etc.

The negative battery cable. (Disconnecting the
negative battery cable will result in the loss of other
on-board memory data, such as preset radio tuning).

6E–43

ENGINE DRIVEABILITY AND EMISSIONS

Tech 2

From 98 MY, Isuzu dealer service departments are
recommended to use Tech 2. Please refer to Tech 2 Tech
2 user guide.

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Legend

(1) PCMCIA Card
(2) RS 232 Loop Back Connector

(3) SAE 16/19 Adaptor
(4) DLC Cable
(5) Tech–2

Tech 2 Features

1. Tech 2 is 12 volt system. Do not apply 24 volt.
2. After connect and/or install Tech 2 body, Vehicle

Communications Interface (VCI) module, PCMCIA
card and DLC connector, connect them to the vehicle
DLC.

3. After power off to the Tech 2, remove and reinstall the

PCMCIA card.

4. The PCMCIA card has a capacity of 10 Megabytes

which is 10 times greater than the memory of the Tech
1 Mass Storage Cartridge.

5. The Tech 2 has the capability of two snapshots.
6. The PCMCIA card is sensitive to magnetism and

static electricity, so care should be taken in the
handling of the card.

7. The Tech 2 can plot a graph when replaying a

snapshot.

8. Always return to the Main Menu to press EXIT key

several times before shutting down.

9. To clear Diagnostic Trouble Codes (DTCs), open

Application Menu and press “F1: Clear DTC Info”.

6E–44

ENGINE DRIVEABILITY AND EMISSIONS

Getting Started

Before operating the Isuzu PCMCIA card with the Tech
2, the following steps must be performed:

1. The Isuzu 98 System PCMCIA card (1) inserts into

the Tech 2 (5).

2. Connect the SAE 16/19 adapter (3) to the DLC cable

(4).

3. Connect the DLC cable to the Tech 2 (5)
4. Make sure the vehicle ignition is off.
5. Connect the Tech 2 SAE 16/19 adapter to the vehicle

DLC.
1. For RHD model: Right front side in the console

box.

2. For LHD model: Left front side in the console box.

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6. The vehicle ignition turns on.
7. Verify the Tech 2 power up display.

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NOTE: The RS232 Loop back connector is only to use for
diagnosis of Tech 2 and refer to user guide of the Tech 2.

Operating Procedure (For Example)

The power up screen is displayed when you power up the
tester with the Isuzu systems PCMCIA card. Follow the
operating procedure below. (Ver. 5.471)

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