Opel Frontera UE. Manual - part 1546

6E–399

6VD1 3.2L ENGINE DRIVEABILITY AND EMISSIONS

Detonation/Spark Knock Symptom

  (Cont'd)

Step

No

Yes

Value(s)

Action

20

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 21

21

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:

D

Visual/physical inspection

D

Tech 2 data

D

Freeze Frame data/Failure Records buffer

D

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

SECTION

6E–400

6VD1 3.2L ENGINE DRIVEABILITY AND EMISSIONS

Rough, Unstable, or Incorrect Idle, Stalling Symptom

 

Step

Action

Value(s)

Yes

No

1

DEFINITION:
Engine runs unevenly at idle.  If severe, the engine or
vehicle may shake.  Engine idle speed may vary in
RPM.   Either condition may be severe enough to stall
the engine.

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

—

Go to 

Step 2

Go to 

OBD

System

Check

2

Was the “Electric Throttle Control (ETC) System
Check” performed?

—

Go to 

Step 3

Go to 

ETC

System

Check

3

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 14

Go to 

Step 4

4

Was a visual/physical check performed?

—

Go to 

Step 5

Go to

Visual/Physic

al Check

5

1. Check the PCM grounds for cleanliness, tightness

and proper routing.  Refer to the PCM wiring
diagrams in 

Electrical Diagnosis.

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

Was a problem found?

—

Verify repair

Go to 

Step  6

6

Observe the long term fuel trim on the Tech 2.

Is the long term fuel trim significantly in the negative
range (rich condition)?

—

Go to 

Step 7

Go to 

Step 8

7

1. Check items that can cause the engine to run rich.

Refer to 

Diagnostic Aids in DTC P0172 Diagnostic

Support.

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

Was a problem found?

—

Verify repair

Go to 

Step 10

8

Is the long term fuel trim significantly in the positive
range (lean condition)?

—

Go to 

Step 9

Go to 

Step 10

9

1. Check items that can cause the engine to run lean.

Refer to 

Diagnostic Aids in DTC P0171 Diagnostic

Support.

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

Was a problem found?

—

Verify repair

Go to 

Step 10

10

1. Check for incorrect idle speed.  Ensure that the

following conditions are present:

D

The engine is fully warm.

D

The accessories are “OFF”.

2. Using a Tech 2, monitor the Engine Speed.

Is the Engine Speed within the specified values?

Desired Idle

Speed

Go to 

Step 12

Go to 

Step 11

SECTION

6E–401

6VD1 3.2L ENGINE DRIVEABILITY AND EMISSIONS

Rough, Unstable, or Incorrect Idle, Stalling Symptom

  (Cont'd)

Step

No

Yes

Value(s)

Action

11

1. Visually/physically inspect for the following

conditions:

D

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

D

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

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

Was a problem found?

—

Verify repair

Go to 

Step 9

12

Check the injector connections.  If any of the injectors
are connected to an incorrect cylinder, correct as
necessary.

Was a problem found?

—

Verify repair

Go to 

Step 13

13

1. Perform the “Injector Coil/Balance Test” in 

Fuel

Metering System.

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

Was a problem found?

—

Verify repair

Go to 

Step 14

14

1. Check for fuel in the pressure regulator vacuum

hose.

2. If fuel is present, replace the fuel pressure regulator

assembly.  Refer to 

Fuel Metering System.

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

Was a problem found?

—

Verify repair

Go to 

Step 15

15

1. Check for proper ignition voltage output with spark

tester J 26792 (ST-125).  Refer to 

Electronic Ignition

System for the procedure.

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

Was a problem found?

—

Verify repair

Go to 

Step 16

16

1. Remove spark plugs.  Check for wet plugs, cracks,

wear, improper gap, burned electrodes, or heavy
deposits.  Refer to 

Electronic Ignition System.

NOTE: If spark plugs are gas or oil fouled, the cause of
the fouling must be determined before replacing the
spark plugs.

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

Was a problem found?

—

Verify repair

Go to 

Step 17

17

1. Check for a loose ignition coil ground and ION

Sensing Module circuit.

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

Was a problem found?

—

Verify repair

Go to 

Step 18

18

1. Check ignition coils for cracks or carbon tracking.
2. If a problem is found, repair as necessary.

Was a problem found?

—

Verify repair

Go to 

Step 19

SECTION

6E–402

6VD1 3.2L ENGINE DRIVEABILITY AND EMISSIONS

Rough, Unstable, or Incorrect Idle, Stalling Symptom

  (Cont'd)

Step

No

Yes

Value(s)

Action

19

Using a Tech 2, monitor the throttle position 1 and 2
angle with the engine idling.

Is the TP angle at the specified value and steady?

8 

∼

 10%

Go to 

Step 20

Refer to 

DTC

for further

diagnosis

20

1. Check the positive crankcase ventilation (PCV)

valve for proper operation.  Refer to 

Crankcase

Ventilation System.

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

Was a problem found?

—

Verify repair

Go to 

Step 21

21

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 (refer to
4L30-E Automatic Transmission Diagnosis).

Was a problem found?

—

Verify repair

Go to 

Step 22

22

1. Check for the following engine mechanical items.

Refer to 

Engine Mechanical for diagnosis

procedures:

D

Low compression

D

Sticking or leaking valves

D

Worn camshaft lobe(s)

D

Camshaft drive belt slipped or stripped

D

Incorrect valve timing

D

Worn rocker arms

D

Broken valve springs

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

Was a problem found?

—

Verify repair

Go to 

Step 23

23

1. Check for faulty motor mounts.  Refer to 

Engine

Mechanical for inspection of mounts.

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

Was a problem found?

—

Verify repair

Go to 

Step 24

24

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:

D

Visual/physical inspection

D

Tech 2 data

D

Freeze Frame data/Failure Records buffer

D

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

SECTION