Opel Frontera UE. Manual - part 196

6E1–82

X22SE 2.2L ENGINE DRIVEABILITY AND EMISSION

D

Rich heated oxygen sensor signal (low air/fuel ratio) –
The idle speed will be too low.  Tech 2 IAC counts will
usually be above 80.  The system is obviously rich
and may exhibit black smoke in the exhaust.
Tech 2 O2 voltage will be fixed at about 750 mV (0.75
V).  Check for high fuel pressure, or a leaking or
sticking injector.  A silicon-contaminated heated
oxygen sensor will show an O2 voltage slow to
respond on Tech 2.

D

Throttle body – Remove the IAC valve and inspect the
bore for foreign material.

D

IAC valve electrical connections – IAC valve
connections should be carefully checked for proper
contact.

D

PCV valve – An incorrect or faulty PCV valve may
result in an incorrect idle speed.  Refer to 

Diagnosis,

Rough Idle, Stalling.  If intermittent poor driveability or
idle symptoms are resolved by disconnecting the
IAC, carefully recheck the connections and valve
terminal resistance, or replace the IAC.

Test Description

Number(s) below refer to the step number(s) on the
Diagnostic Chart.
1. The Tech 2 is used to extend and retract the IAC

valve.  Valve movement is verified by an engine
speed change.  If no change in engine speed
occurs, the valve can be resettled when removed
from the throttle body.

2. This step checks the quality of the IAC movement in

step 1.  Between 700 revolutions per minute (RPM)
and about 1500 RPM, the engine speed should
change smoothly with each flash of the tester light
in both extend and retract.  If the IAC valve is
retracted beyond the control range (about 1500
RPM), it may take many flashes to extend the IAC
valve before engine speed will begin to drop.  This
is normal on certain engines.  Fully extending the
IAC may cause engine stall.  This may be normal.

Idle Air Control (IAC) System Check

 

Step

Action

Value(s)

Yes

No

1

1. Ignition “OFF.”
2. Connect the Tech 2.
3. Set the parking brake.
4. Block the wheels.
5. Turn the air conditioning “OFF.”
6. Idle the engine in Park (A/T) or Neutral (M/T).
7. Operate the IAC test.
8. The engine speed should decrease and increase as

the IAC is cycled.

Does the RPM change?

—

Go to 

Step 2

Go to 

Step 3

2

RPM should change smoothly.

Does the RPM change within the range specified?

700-1500

RPM

—

Go to 

Step 3

3

Check the IAC passages.

Are the IAC passages OK?

—

Go to 

Step 4

Go to 

Step 5

4

Clear any obstruction from the IAC passages.

Is the action complete?

—

Verify repair

—

5

Replace the IAC.  Refer to 

On-Vehicle Service, Idle Air

Control Valve.

Is the action complete?

—

Verify repair

—

6E1–83

X22SE 2.2L ENGINE DRIVEABILITY AND EMISSION

EXHAUST GAS RECIRCULATION (EGR) SYSTEM CHECK

D06RX113

Circuit Description

A properly operating exhaust gas recirculation (EGR)
system will directly affect the air/fuel requirements of the
engine. Since the exhaust gas introduced into the air/fuel
mixture is an inert gas (contains very little or no oxygen),
less fuel is required to maintain a correct air/fuel ratio.
Introducing exhaust gas into the combustion chamber
lowers combustion temperatures and reduces the
formation of oxides of nitrogen (NOx) in the exhaust gas.
Lower combustion temperatures also prevent detonation.
If the EGR pintle were to stay closed, the inert exhaust
gas would be replaced with air and the air/fuel mixture
would be leaner. The powertrain control module (ECM)
would compensate for the lean condition by adding fuel,
resulting in higher long term fuel trim values.

Diagnostic Aids

The EGR valve chart is a check of the EGR system. An
EGR pintle constantly in the closed position could cause
detonation and high emissions of NOx. It could also result
in high long term fuel trim values in the open throttle cell,
but not in the closed throttle cell. An EGR pintle constantly
in the open position would cause rough idle. Also, an EGR
valve mounted incorrectly (rotated 180

°

) could cause a

rough idle without setting an EGR DTC. Check for the
following items:

D

EGR passages – Check for restricted or blocked EGR
passages.

D

Manifold absolute pressure sensor – A manifold
absolute pressure sensor may shift in calibration
enough to affect fuel delivery. Refer to Manifold
Absolute Pressure Output Check. 

6E1–84

X22SE 2.2L ENGINE DRIVEABILITY AND EMISSION

Exhaust Gas Recirculation (EGR) System Check

 

Step

Action

Value(s)

Yes

No

1

Check the EGR valve for looseness.

Is the EGR valve loose?

—

Go to Step 2 

Go to Step 3 

2

Tighten the EGR valve.

Is the action complete?

—

Verify repair

—

3

1. Place the transmission selector in Park or Neutral.
2. Start the engine and idle until warm (”Closed Loop”).
3. Using a Tech 2, command EGR ”50% ON.”

Does the engine idle rough and lose RPMs?

—

EGR system

working

properly. No

problem

found.

Go to Step 4 

4

1. Engine OFF.
2. Ignition ON.
3. Using a test light to ground, check the EGR harness

between the ignition feed and ground.

Does the test light illuminate?

—

Go to Step 6 

Go to Step 5 

5

Repair the EGR harness ignition feed.

Was the problem corrected?

—

Verify repair

Go to Step 6 

6

1. Remove the EGR valve.
2. Visually and physically inspect the EGR valve

pintle, valve passages and adapter for excessive
deposits, obstructions or any restrictions.

Does the EGR valve have excessive deposits,
obstructions or any restrictions?

—

Go to Step 7 

Go to Step 8 

7

Clean or replace EGR system components as
necessary.

Was the problem corrected?

—

Verify repair

Go to Step 8 

8

1. Ground the EGR valve metal case to battery (–).
2. Using a Tech 2, command EGR ON and observe the

EGR valve pintle for movement.

Does the EGR valve pintle move according to
command?

—

Go to Step 9 

Go to DTC

P0404 chart 

9

1. Remove the EGR inlet and outlet pipes from the

intake and exhaust manifolds.

2. Visually and physically inspect manifold EGR ports

and EGR inlet and outlet pipes for blockage or
restriction caused by excessive deposits or other
damage.

Do the manifold EGR ports or inlet and outlet pipes
have excessive deposits, obstructions, or any
restrictions?

—

Go to Step 10

EGR system

working

properly. No

problem

found.

10

Clean or replace EGR system components as
necessary.

Is the action complete?

—

Verify repair

—

6E1–85

X22SE 2.2L ENGINE DRIVEABILITY AND EMISSION

MANIFOLD ABSOLUTE PRESSURE (MAP) OUTPUT CHECK

D06RX114

Circuit Description

The manifold absolute pressure (MAP) sensor measures
the changes in the intake MAP which result from engine
load (intake manifold vacuum) and engine speed
changes; and converts these into a voltage output. The
powertrain control module (ECM) sends a 5–volt
reference voltage to the MAP sensor. As the MAP
changes, the output voltage of the sensor also changes.
By monitoring the sensor output voltage, the ECM knows
the MAP. A lower pressure (low voltage) output voltage
will be about 1–2 volts at idle. Higher pressure (high
voltage) output voltage will be about 4–4.8 volts at wide
open throttle. The MAP sensor is also used, under certain
conditions, to measure barometric pressure, allowing the
ECM to make adjustments for different altitudes. The
ECM uses the MAP sensor to diagnose proper operation
of the EGR system, in addition to other functions.

Test Description

IMPORTANT:

Be sure to use the same diagnostic test

equipment for all measurements.
The number(s) below refer to the step number(s) on the
Diagnostic Chart:

1. When you compare the Tech 2 readings to a known

good vehicle, it is important to compare vehicles
that use MAP sensors that have the same part
number.

2. Applying 34 kPa (10 Hg) vacuum to the MAP sensor

should cause the voltage to be 1.5–2.1 volts less
than the voltage at step 1. Upon applying vacuum to
the sensor, the change in voltage should be
instantaneous. A slow voltage change indicates a
faulty sensor.

3. Check the vacuum hose to the sensor for leaking or

restriction. Be sure that no other vacuum devices
are connected to the MAP hose.

IMPORTANT:

Make sure the electrical connector

remains securely fastened.

4. Disconnect the sensor from the bracket. Twist the

sensor with your hand to check for an intermittent
connection. Output changes greater than 0.10 volt
indicate a bad sensor.