Opel Frontera UBS. Manual - part 1184

6E–102

ENGINE DRIVEABILITY AND EMISSIONS

PCM Diagnostic Trouble Codes

6E–103

ENGINE DRIVEABILITY AND EMISSIONS

PCM Diagnostic Trouble Codes (Cont’d)

6E–104

ENGINE DRIVEABILITY AND EMISSIONS

Diagnostic Trouble Code (DTC) P0101 MAF System Performance

D06RW103

Circuit Description

The mass air flow (MAF) sensor measures the amount of
air which passes through it into the engine during a given
time.  The powertrain control module (PCM) uses the
mass air flow information to monitor engine operating
conditions for fuel delivery calculations.  A large quantity
of air entering the engine indicates an acceleration or high
load situation, while a small quantity or air indicates
deceleration or idle.
The MAF sensor produces a frequency signal which can
be monitored using a Tech 2.  DTC P0101 will be set if the
signal from the MAF sensor does not match a predicted
value based on throttle position and engine RPM.

Conditions for Setting the DTC

D

The engine is running.

D

No TP sensor or MAP sensor DTCs are set.

D

The throttle is steady, TP angle doesn’t change by
more than 1%.

D

System voltage is between 11.5 volts and 16 volts.

D

Calculated air flow is between 25 g/second and 40
g/second.

D

Above conditions present for at least 1 second.

D

MAF signal frequency indicates an airflow significantly
higher or lower than a predicted value based on throttle
position and engine RPM for a total of 12.5 seconds
over a 25-second period of time.

Action Taken When the DTC Sets

D

The PCM will illuminate the malfunction indicator lamp
(MIL) after the second consecutive trip in which the
fault is detected.

D

The PCM calculates an airflow value based on idle air
control valve position, throttle position, RPM and
barometric pressure.

D

The PCM will store conditions which were present
when the DTC was set as Freeze Frame and in the
Failure Records data.

Conditions for Clearing the MIL/DTC

D

DTC P0101 can be cleared by using the Tech 2 “Clear
Info” function or by disconnecting the PCM battery
feed.

Diagnostic Aids

An intermittent may be caused by the following:

D

Poor  connections.

D

Mis-routed harness.

D

Rubbed through wire insulation.

D

Broken wire inside the insulation.

Refer to Intermittents under service category Symptoms.
Any un-metered air may cause this DTC to set.  Check for
the following:

D

The duct work at the MAF sensor for leaks.

D

An engine vacuum leak.

D

The PCV system for vacuum leaks.

D

An incorrect PCV valve.

6E–105

ENGINE DRIVEABILITY AND EMISSIONS

D

The engine oil dip stick not fully seated.

D

The engine oil fill cap loose or missing.

Test Description

Number(s) below refer to the step number(s) on the
Diagnostic Chart.
2. The MAF system performance or “rationality”

diagnostic uses the MAP sensor signal along with
other input to calculate an expected airflow rate that
is then compared to the actual measured airflow
from the MAF sensor.  The first few steps of this
table verify that the MAP sensor is working properly.

6. Using Freeze Frame and/or Failure Records data

may aid in locating an intermittent condition.  If the
DTC cannot be duplicated, the information included
in the Freeze Frame and/or Failure Records data
can be useful in determining how many miles since
the DTC set.  The Fail Counter and Pass Counter
can also be used to determine how many ignition
cycles the diagnostic reported a pass and/or a fail.
Operate the vehicle within the same Freeze Frame
conditions (RPM, load, vehicle speed , temperature,
etc.) that were noted.  This will isolate when the
DTC failed.

For any test that requires back probing the PCM or
component harness connectors, use the Connector
Test Adapter Kit J 35616-A.  Using this kit will
prevent any damage to the harness connector
terminals.

7. Any un-metered air may cause this DTC to set.

Check the PVC system for vacuum leaks.  Also
inspect the dip stick for being pulled out.  Check the
oil fill cap for being loose.

8. Verifies the signal circuit from the MAF sensor

electrical connector to the PCM.

9. Verifies whether a ground and B+ circuit is available.

10. Checks a signal circuit for an open.

11. Checks for a signal circuit shorted to B+.

DTC P0101 – MAF System Performance

 

Step

Action

Value(s)

Yes

No

1

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

—

Go to 

Step 2

Go to 

OBD

System

Check

2

1. Ignition “ON,” engine “OFF.”
2. Using a Tech 2, select “MAP” from the Engine 1

Data List.

Is the value displayed greater than the value shown?

85 kPa

Go to 

Step 3

Go to

Step 13

3

1. Remove the MAP sensor from the intake manifold

but leave the electrical harness connected.

2. Connect a hand operated vacuum pump to the MAP

sensor.

3. Observe the MAP display while slowly applying

vacuum up to 20” Hg as indicated on the pump
gauge.

Each 1” of vacuum applied should result in a 3 to 4 kPa
drop in the MAP sensor value on the Tech 2 and the
value should change smoothly with each increase in
vacuum.

Did the MAP value change smoothly through the entire
range of the test without any erratic readings?

—

Go to 

Step 13

Go to

 Step 4

4

With 20” Hg vacuum applied to the MAP sensor, is the
MAF sensor reading the same or less than the value
shown?

34 kPa

Go to 

Step 5

Go to

 Step 13

5

Disconnect the vacuum source from the MAP sensor.

Does the MAP sensor reading return to its original
value?

—

Go to 

Step 6

Go to

 Step 13