Opel Frontera UBS. Manual - part 2427

6E–22

4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS

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4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS

Abbreviations Charts

List of abbreviations which may be used in this section.

Abbreviations

Term

Abbreviations

Term

A/C

Air Conditioner

BLK

Black

A/T

Automatic Transmission

BLU

Blue

ACC

Accessory

BRN

Brown

AP

Accel Position

GRN

Green

ASM

Assembly

GRY

Gray

CKP

Crank Position

LT BLU

Light Blue

CMP

Cam Position

LT GRN

Light Green

DLC

Data Link Connector

ORN

Orange

DTC

Diagnosis Trouble Code

PNK

Pink

DVM

Digital Volt Meter

RED

Red

ECM

Engine Control Module

VIO

Violet

ECT

Engine Coolant Temperature

WHT

White

EGR

Exhaust Gas Recircuration

YEL

Yellow

EVRV

Electric Vacuum Regulating Valve

EXH

Exhaust

FT

Fuel Temperature

IAT

Intake Air Temperature

IG

Ignition

ITP

Intake Throttle Position

M/T

Manual Transmission

MAP

Manifold Absolute Pressure

MIL

Mulfunction Indicator Lamp

OBD

On-Board Diagnostic

OT

Oil Temperature

QOS

Quick on Start System

QWS

Quick Warming-Up System

RP

Rail Pressure

RPCV

Rail Pressure Control Valve

SRS

Supplemental Restraint System

ST

Start

SW

Switch

TEMP

Temperature

TOD

Torque on Demand

VSS

Vehicle Speed Sensor

VSV

Vacuum Switching Valve

HEUI

Hydraulically Actuated Electronically Controlled Unit
Injector

Injector

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4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS

Diagnosis

Strategy-Based Diagnostics

Strategy-Based Diagnostics

The strategy-based diagnostic is a uniform approach to
repair all Electrical/Electronic (E/E) systems.  The
diagnostic flow can always be used to resolve an E/E
system problem and is a starting point when repairs are
necessary.  The following steps will instruct the technician
how to proceed with a diagnosis:

1. Verify the customer complaint.

D

To verify the customer complaint, the technician
should know the normal operation of the system.

2. Perform preliminary checks.

D

Conduct a thorough visual inspection.

D

Review the service history.

D

Detect unusual sounds or odors.

D

Gather diagnostic trouble code information to
achieve an effective repair.

3. Check bulletins and other service information.

D

This includes videos, newsletters, etc.

4. Refer to service information (manual) system

check(s).

D

“System checks” contain information on a system
that may not be supported by one or more DTCs.
System checks verify proper operation of the
system.  This will lead the technician in an
organized approach to diagnostics.

5. Refer to service diagnostics.

DTC Stored

Follow the designated DTC chart exactly to make an
effective repair.

No DTC

Select the symptom from the symptom tables.  Follow the
diagnostic paths or suggestions to complete the repair.
You may refer to the applicable component/system check
in the system checks.

No Matching Symptom

1. Analyze the complaint.
2. Develop a plan for diagnostics.
3. Utilize the wiring diagrams and the theory of

operation.

Call technical assistance for similar cases where repair
history may be available.  Combine technician knowledge
with efficient use of the available service information.

Intermittents

Conditions that are not always present are called
intermittents.  To resolve intermittents, perform the
following steps:

1. Observe history DTCs, DTC modes, and freezeframe

data.

2. Evaluate the symptoms and the conditions described

by the customer.

3. Use a check sheet or other method to identify the

circuit or electrical system component.

4. Follow the suggestions for intermittent diagnosis

found in the service documentation.

Most scan tools, such as the Tech 2 and the DVM, have
data-capturing capabilities that can assist in detecting
intermittents.

No Trouble Found

This condition exists when the vehicle is found to operate
normally.  The condition described by the customer may
be normal.  Verify the customer complaint against another
vehicle that is operating normally.  The condition may be
intermittent.  Verify the complaint under the conditions
described by the customer before releasing the vehicle.

1. Re-examine the complaint.

When the complaint cannot be successfully found or
isolated, a re-evaluation is necessary.  The complaint
should be re-verified and could be intermittent as
defined in 

Intermittents, or could be normal.

2. Repair and verify.

After isolating the cause, the repairs should be made.
Validate for proper operation and verify that the
symptom has been corrected.  This may involve road
testing or other methods to verify that the complaint
has been resolved under the following conditions:

D

Conditions noted by the customer.

D

If a DTC was diagnosed, verify a repair by
duplicating conditions present when the DTC was
set as noted in the Failure Records or Freeze
Frame data.

Verifying Vehicle Repair

Verification of the vehicle repair will be more
comprehensive for vehicles with OBD system
diagnostics.  Following a repair, the technician should
perform the following steps:

IMPORTANT:

Follow the steps below when you verify

repairs on OBD systems.  Failure to follow these steps
could result in unnecessary repairs.

1. Review and record the Failure Records and the

Freeze Frame data for the DTC which has been
diagnosed (Freeze Frame data will only be stored for
the MIL (“Check Engine” lamp) has been requested).

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

Failure Records and 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.

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4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS

General Service Information

Serviceability Issues

Non-OEM Parts
All of the OBD diagnostics have been calibrated to run
with OEM parts.  Accordingly, if commercially sold sensor
or switch is installed, it makes a wrong diagnosis and turn
on the MIL (“Check Engine” lamp).
Aftermarket electronics, such as cellular phones,
stereos, and anti-theft devices, may radiate EMI into the
control system if they are improperly installed.  This may
cause a false sensor reading and turn on the MIL (“Check
Engine” lamp).

Poor Vehicle Maintenance
The sensitivity of OBD diagnostics will cause the MIL
(“Check Engine” lamp) to turn on if the vehicle is not
maintained properly.  Restricted oil filters, fuel filters, and
crankcase deposits due to lack of oil changes or improper
oil viscosity can trigger actual vehicle faults that were not
previously monitored prior to OBD.  Poor vehicle
maintenance can not be classified as a “non-vehicle
fault”, but with the sensitivity of OBD diagnostics, vehicle
maintenance schedules must be more closely followed.

Related System Faults
Many of the OBD system diagnostics will not run if the
ECM detects a fault on a related system or component.

Visual/Physical Engine Compartment
Inspection

Perform a careful  visual and physical engine
compartment inspection when performing any diagnostic
procedure or diagnosing the cause of an emission test
failure.  This can often lead to repairing a problem without
further steps.  Use the following guidelines when
performing a visual/physical inspection:

D

Inspect all vacuum hoses for punches, cuts,
disconnects, and correct routing.

D

Inspect hoses that are difficult to see behind other
components.

D

Inspect all wires in the engine compartment for proper
connections, burned or chafed spots, pinched wires,
contact with sharp edges or contact with hot exhaust
manifolds or pipes.

Basic Knowledge of Tools Required

NOTE: Lack of basic knowledge of this powertrain when
performing diagnostic procedures could result in an
incorrect diagnosis or damage to powertrain
components.  Do not attempt to diagnose a powertrain
problem without this basic knowledge.

A basic understanding of hand tools is necessary to effec-
tively use this section of the Service Manual.

Serial Data Communications

Class II Serial Data Communications

This vehicle utilizes the “Class II” communication system.
Each bit of information can have one of two lengths: long

or short.  This allows vehicle wiring to be reduced by
transmitting and receiving multiple signals over a single
wire.  The messages carried on Class II data streams are
also prioritized.  If two messages attempt to establish
communications on the data line at the same time, only
the message with higher priority will continue.  The device
with the lower priority message must wait.
On this vehicle the Tech 2 displays the actual values for
vehicle parameters.  It will not be necessary to perform
any conversions from coded values to actual values.

On-Board Diagnostic (OBD)

On-Board Diagnostic Tests

A diagnostic test is a series of steps, the result of which is
a pass or fail reported to the diagnostic executive.  When
a diagnostic test reports a pass result, the diagnostic
executive records the following data:

D

The diagnostic test has been completed since the last
ignition cycle.

D

The diagnostic test has passed during the current
ignition cycle.

D

The fault identified by the diagnostic test is not
currently active.

When a diagnostic test reports a fail result, the diagnostic
executive records the following data:

D

The diagnostic test has been completed since the last
ignition cycle.

D

The fault identified by the diagnostic test is currently
active.

D

The fault has been active during this ignition cycle.

D

The operating conditions at the time of the failure.

Comprehensive Component Monitor
Diagnostic Operation

Comprehensive component monitoring diagnostics are
required to operate engine properly.

Input Components:
Input components are monitored for circuit continuity and
out-of-range values.  This includes rationality checking.
Rationality checking refers to indicating a fault when the
signal from a sensor does not seem reasonable. Accel
Position (AP) sensor that indicates high throttle position
at low engine loads or MAP voltage. Input components
may include, but are not limited to the following sensors:

D

Intake Air Temperature (IAT) Sensor

D

Crankshaft Position (CKP) Sensor

D

Intake throttle Position (ITP) Sensor

D

Engine Coolant Temperature (ECT) Sensor

D

Camshaft Position (CMP) Sensor

D

Manifold absolute Pressure (MAP) Sensor

D

Accel Position Sensor

D

Fuel Temp Sensor

D

Rail Pressure Sensor

D

Oil Temp Sensor

D

EGR Pressure Sensor

D

Vehicle Speed Sensor