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Opel Frontera UBS. Manual - part 298

6E–98

ENGINE DRIVEABILITY AND EMISSIONS

Exhaust Gas Recirculation (EGR) System Check

Step

Action

Value(s)

Yes

Check the EGR valve for looseness.

Is the EGR valve Loose?

—

Go to

Step 2

Go to

Step 3

Tighten the EGR valve.

Is the action complete?

—

Verify repair

—

1. Place the transmission selector in Park or Neutral.
2. Start the engine and idle until warm.
3. Using 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

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

between the EGR valve and the ignition feed.

Does the test light illuminate?

—

Go to

Step 6

Go to

Step 5

Repair the EGR harness ignition feed.

Was the problem corrected?

—

Verify repair

Go to

Step 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

Clean or replace EGR system components as
necessary.

Was the problem corrected?

—

Verify repair

Go to

Step 8

1. Ground the EGR valve metal case to battery (–).
2. Using 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

P1406 chart

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.

Clean or replace EGR system components as
necessary.

Is the action complete?

—

Verify repair

—

6E–99

ENGINE DRIVEABILITY AND EMISSIONS

Manifold Absolute Pressure (MAP) Output Check

D06RW102

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 (PCM) 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 the sensor output voltage, the PCM
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 PCM to make adjustments for different
altitudes. The PCM uses the MAP sensor to diagnose
proper operation of the EGR system, in addition to other
functions.

Test Description

IMPORTANT:

Be sure to used the same diagnostic test

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

6E–100

ENGINE DRIVEABILITY AND EMISSIONS

Manifold Absolute Pressure (MAP) Output Check

Step

Action

Value(s)

Yes

1. Turn the ignition “OFF”and leave it “OFF” for 15

seconds.

2. Ignition “ON.” Don’t crank engine.
3. Tech 2 should indicate a manifold absolute pressure

(MAP) sensor voltage.

4. Compare this scan reading to scan reading of a

known good vehicle obtained using the exact same
procedure as in Steps 1-4.

Is the voltage reading the same +/–0.40 volt?

—

Go to

Step 2

Go to

Step 5

1. Disconnect the vacuum hose at the MAP sensor

and plug the hose.

2. Connect a hand vacuum pump to the MAP sensor.
3. Start the engine.
4. Apply 34 kPa (10 Hg) of vacuum and note the

voltage change.

Is the voltage change 1.5-2.1 volts less than Step 1?

—

Go to

Step 3

Go to

Step 4

No trouble found. Check the sensor cover for leakage
or restriction.

Does the hose supply vacuum to the MAP sensor only?

—

Go to

Step 5

Go to

Step 4

Repair the material to block.

Is the action complete?

—

Verify repair

—

Check the sensor connection.

Is the sensor connection good?

—

Go to

Step 6

Go to

Step 7

Replace the sensor. Refer to

On-Vehicle Service, MAP

Sensor.

Is the action complete?

—

Verify repair

—

Repair the poor connection.

Is the action complete?

—

Verify repair

—

6E–101

ENGINE DRIVEABILITY AND EMISSIONS

PCM Diagnostic Trouble Codes

The following table lists the diagnostic trouble codes
supported by this vehicle application. If any DTCs not
listed here are displayed by a Tech 2, the Tech 2 data may
be faulty; notify the Tech 2 manufacturer of any DTCs
displayed that are not included in the following table.
A - Emission related P-code, check engine light on as

soon as a failure detected.

B - Emission related P-code, check engine light on if a

failure detected in two consecutive trips.

C - Non emission related P-code, check engine light on

if a failure detected in one trip.

D - Non emission related P-code, no check engine

light, but P-code will be set if a failure detected.

X - Do not check.

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