Content .. 512 513 514 515 ..

Opel Frontera UBS. Manual - part 514

6E–186

4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS

Poor Fuel Economy Symptom

(Cont'd)

Step

Yes

Value(s)

Action

1. Check the TCC operation. Refer to

Transmission

Diagnosis.

2. If a problem is found, repair as necessary.

Was a problem found?

—

Verify repair

Go to

Step 12

1. Check the exhaust system for possible restriction:

Inspect the exhaust system for damaged or
collapsed pipes.

Inspect the muffler for heat distress or possible
internal failure.

2. If a problem is found, repair as necessary.

Was a problem found?

—

Verify repair

Go to

Step 13

Check for proper calibration of the speedometer.

Does the speed indicated on the speedometer closely
match the vehicle speed displayed on the Tech 2?

—

Go to

Step 15

Go to

Step 14

Diagnose and repair an inaccurate speedometer
condition as necessary. Refer to

Vehicle Speed

Sensor in Electrical Diagnosis.

Was a problem found?

—

Verify repair

—

1. Check the air intake system and the crankcase for

air leaks. Refer to

Air Intake System and

Crankcase Ventilation System.

2. If a problem is found, repair as necessary.

Was a problem found?

—

Verify repair

Go to

Step 16

1. Review all diagnostic procedures within this table.
2. When all procedures have been completed and no

malfunctions have been found, review/inspect the
following:

Visual/physical inspection

Tech 2 data

Freeze Frame data/Failure Records buffer

All connections within a suspected circuit
and/or system.

3. If a problem is found, repair as necessary.

Was a problem found?

—

Verify repair

Go to

Step 17

Perform the procedure in

Injector Test.

Was the fuel pressure normal?

—

Contact

Technical

Assistance

Verify repair

6E–187

4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS

Excessive Exhaust Emissions or Odors Symptom

Step

Action

Value(s)

Yes

DEFINITION:
Vehicle fails an emission test. Vehicle has excessive
“rotten egg” smell. (Excessive odors do not necessarily
indicate excessive emissions.)

Was the “On-Board Diagnostic (OBD) System Check”
performed?

—

Go to

Step 2

Go to

OBD

System

Check

1. Perform a bulletin search.
2. If a bulletin that addresses the symptom is found,

correct the condition as instructed in the bulletin.

Was a bulletin found that addresses the symptom?

—

Verify repair

Go to

Step 3

Was a thorough visual/physical check performed?

—

Go to

Step 4

Go to

Visual/

Physical

Check

1. Check for vacuum leaks. Check vacuum lines,

intake manifold, throttle body, etc.

2. If a problem is found, repair as necessary.

Were any vacuum leaks located?

—

Verify repair

Go to

Step 5

1. Check the fuel cap for proper installation.
2. Secure the fuel cap if necessary.

Was the fuel cap installed properly?

—

Go to

Step 6

Verify repair

1. Injector Test

Operate the each injector by Tech 2 with the
ignition “ON” and check if the working noise
confirm.

2. If a problem is found, check the harness or replace

the injector.

Is the action complete?

—

Verify repair

Go to

Step 7

1. Refer to

Engine Cooling for cooling system

diagnosis.

2. If a problem is found, repair as necessary.

Was a problem found?

—

Verify repair

Go to

Step 8

1. Check for an engine mechanical problem.

Perform a cylinder compression check (Refer to
Engine Mechanical).

2. If a problem is found, repair as necessary.

Was a problem found?

—

Verify repair

Go to

Step 9

1. Review all diagnostic procedures within this table.
2. If all procedures have been completed and no

malfunctions have been found, review/inspect the
following:

Visual/physical inspection

Tech 2 data

Freeze Frame data/Failure Records butter

All electrical connections within a suspected
circuit and/or system.

3. If a problem is found, repair as necessary.

Was a problem found?

—

Verify repair

Contact

Technical

Assistance

6E–188

4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS

Dieseling, Run-On Symptom

Step

Action

Value(s)

Yes

DEFINITION:
Engine continues to run after key is turned “OFF,” but
runs very rough. If engine runs smooth, check ignition
switch and adjustment.

Was the “On-Board Diagnostic (OBD) System Check”
performed?

—

Go to

Step 2

Go to

OBD

System

Check

1. Perform a bulletin search.
2. If a bulletin that addresses the symptom is found,

correct the condition as instructed in the bulletin.

Was a bulletin found that addresses the symptom?

—

Verify repair

Go to

Step 3

Was a visual/physical check performed?

—

Go to

Step 4

Go to

Visual/

Physical

Check

1. Check for a short between B+ and any of the ignition

feed circuits.

2. If a problem is found, repair as necessary.

Was a problem found?

—

Verify repair

Go to

Step 5

1. Review all diagnostic procedures within this table.
2. If all procedures have been completed and no

malfunctions have been found, review/inspect the
following:

Visual/physical inspection

Tech 2 data

Freeze Frame data/Failure Records butter

All electrical connections within a suspected
circuit and/or system

3. If a problem is found, repair as necessary.

Was a problem found?

—

Verify repair

Contact

Technical

Assistance

6E–189

4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS

Cuts Out, Symptom

Step

Action

Value(s)

Yes

DEFINITION:
Steady pulsation or jerking that follows engine speed;
usually more pronounced as engine load increases.

Was the “On-Board Diagnostic (OBD) System Check”
performed?

—

Go to

Step 2

Go to

OBD

System

Check

1. Perform a bulletin search.
2. If a bulletin that addresses the symptom is found,

correct the condition as instructed in the bulletin.

Was a bulletin found that addresses the symptom?

—

Go to

Step 7

Go to

Step 3

Was a visual/physical check performed?

—

Go to

Step 4

Go to

Visual/

Physical

Check

1. Check the ECM grounds for clearness, tightness

and proper routing. Refer to the ECM wiring
diagrams in

Electrical Diagnosis.

2. If a problem is found, repair as necessary.

Was a problem found?

—

Verify repair

Go to

Step 5

1. Check for incorrect idle speed. Ensure that the

following conditions are present:

The engine is fully warm.

The accessories are “off.”

2. Using a Tech 2, monitor the AP position.

Is the AP position within the specified values?

Go to

Step 6

Go to

Step 7

1. Visually/physically inspect for the following

conditions:

Restricted air intake system. Check for a
possible collapsed air intake duct, restricted
air filter element, or foreign objects blocking
the air intake system.

Check the Throttle body.

Large vacuum leak. Check for a condition that
causes a large vacuum leak, such as an
incorrectly installed or faulty VSV or brake
booster hose disconnected .

2. If a problem is found, repair as necessary.

Was a problem found?

—

Verify repair

Go to

Step 7

Using a Tech 2, monitor the AP angle with the engine
idling.

Is the AP angle at the specified value and steady?

Go to

Step 8

Refer to

DTC

P0123 for

further

diagnosis

1. Check the transmission range switch circuit. Use a

Tech 2 and be sure the Tech 2 indicates that the
vehicle is in drive with the gear selector in drive or
overdrive.

2. If a problem is found, diagnose and repair the

transmission range switch as necessary.

Was a problem found?

—

Verify repair

Go to

Step 9

Content .. 512 513 514 515 ..