Opel Frontera UE. Manual - part 1487

6E–163

6VD1 3.2L ENGINE DRIVEABILITY AND EMISSIONS

measurement that is not correct. Disconnect the MAF
sensor to see if rich condition is corrected. If so,
replace MAF sensor.

Check for leaking fuel pressure regulator diaphragm by
checking vacuum line to regulator for the presence of
fuel. There should be no fuel in the vacuum line.

TP sensor – An intermittent TP sensor output will
cause the system to go rich, due to a false indication
of the engine accelerating.

Shorted Heated Oxygen Sensor (HO2S)– If the HO2S
is internally shorted, the HO2S voltage displayed on
the Tech 2 will be over 1 volt. Try disconnecting the
affected HO2S with the key “ON”, engine “OFF”. If the
displayed HO2S voltage changes from over 1000 mV
to around 450 mV, replace the HO2S. Silicon
contamination of the HO2S can cause a high HO2S
voltage to be indicated. This condition is indicated by
powdery deposit on the portion of the HO2S exposed
to the exhaust stream. If contamination is noticed,
replace the affected HO2S.

Open HO2S Signal Circuit of Faulty HO2S– A poor
connection or open in the HO2S signal circuit can
cause the DTC to set during deceleration fuel mode.
An HO2S which is faulty and not allowing a full voltage

switch between the rich and lean thresholds can also
cause the condition. Operate the vehicle while
monitoring the HO2S voltage with a Tech 2. If the
HO2S is limited within a range between 300 mV to
600 mV, check the HO2S signal circuit wiring and
associated terminal connections.

If none of the above conditions are present, replace the
affected HO2S.

Test Description

Number(s) below refer to the step number(s) on the
Diagnostic Chart.
3. DTC P0152 failing during deceleration fuel cutoff

mode operation may indicate a condition described
in the “Diagnostic Aids” above. If the DTC P0152
test passes while the Failure Records conditions are
being duplicated, an intermittent condition is
indicated.

Reviewing the Failure Records vehicle mileage since the
diagnostic test last failed may help determine how often
the condition that caused the DTC to be set occurs. This
may assist in diagnosing the condition.

DTC P0152 – HO2S Circuit High Voltage Bank 2 Sensor 1

Step

Action

Value(s)

Yes

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

—

Go to

Step 2

Go to

OBD

System

Check

1. Install the Tech 2.
2. Engine is at operating temperature.
3. Operate the vehicle within the parameters specified

under “Conditions for Setting the DTC” criteria
included in Diagnostic Support.

4. Using a Tech 2, monitor Bank 2 HO2S 1 voltage.

Does the Bank 2 HO2S 1 voltage remain above the
specified value?

952 mV

(500 mV in

deceleration

fuel cut-off

mode)

Go to

Step 4

Go to

Step 3

1. Ignition “ON”.
2. Review and record Tech 2 Failure Records data.
3. Operate the vehicle within Failure Records

conditions as noted.

4. Using a Tech 2, monitor “DTC” info for DTC P0152

until the DTC P0152 test runs.

5. Note the test result.

Does the Tech 2 indicate DTC P0152 failed this
ignition?

—

Go to

Step 4

Refer to

Diagnostic

Aids

1. Ignition “OFF”.
2. Disconnect Bank 2 HO2S 1.
3. Ignition “ON”.
4. At HO2S Bank 2 Sensor 1 connector (PCM side)

use a DVM to measure voltages at the high and low
signal terminals.

Are the voltages in the specified range?

3-4 V

Go to

Step 5

Go to

Step 6

Repair short to voltage in signal circuit.

Is the action complete?

—

Verify repair

—

SECTION

6E–164

6VD1 3.2L ENGINE DRIVEABILITY AND EMISSIONS

DTC P0152 – HO2S Circuit High Voltage Bank 2 Sensor 1

(Cont'd)

Step

Yes

Value(s)

Action

1. Ignition “ON”, engine“OFF”.
2. At Bank 2 HO2S 1 connector (PCM side) jumper

both the HO2S high and low signal circuits (PCM
side) to ground.

3. Using a Tech 2, monitor Bank 2 HO2S 1 voltage.

Is Bank 2 HO2S 1 voltage below the specified value?

10 mV

Go to

Step 7

Go to

Step 8

1. Disconnect the jumpers to ground from Bank 2

HO2S 1 PCM-side connector.

2. With the HO2S 1 connector disconnected, monitor

Bank 2 HO2S 1 voltage.

Is the Bank 2 HO2S 1 voltage between the specified
values?

425-475 mV

Refer to

Diagnostic

Aids

Go to

Step 8

Replace the PCM.

IMPORTANT: The replacement PCM must be
programmed. Refer to

On-Vehicle Service in

Powertrain Control Module and Sensors for
procedures.

And also refer to latest Service Bulletin.

Check to see if the Latest software is released or not.
And then Down Load the LATEST PROGRAMMED
SOFTWARE to the replacement PCM.

Is the action complete?

—

Verify repair

—

SECTION

6E–165

6VD1 3.2L ENGINE DRIVEABILITY AND EMISSIONS

Diagnostic Trouble Code (DTC)

P0154 HO2S Circuit Insufficient Activity Bank 2 Sensor 1

060R100133

Circuit Description

The powertrain control module (PCM) supplies a bias
voltage of about 450 mV between the heated oxygen
sensor (HO2S) high and low circuits. When measured
with a 10 megaohm digital voltmeter, this may display as
low as 320 mV. The oxygen sensor varies the voltage
within a range of about 1000 mV when the exhaust is rich,
down through about 10 mV when exhaust is lean. The
PCM constantly monitors the HO2S signal during “closed
loop” operation and compensates for a rich or lean
condition by decreasing or increasing injector pulse width
as necessary. If the Bank 2 HO2S 1 voltage remains at or
near the 450 mV bias for an extended period of time, DTC
P0154 will be set, indicating an open sensor signal or
sensor low circuit.
Heated oxygen sensors are used to minimize the amount
of time required for “closed loop” fuel control operation
and to allow accurate catalyst monitoring. The oxygen
sensor heater greatly decreases the amount of time
required for fuel control sensors Bank 1 HO2S 1 and Bank
2 HO2S 1 to become active. Oxygen sensor heaters are
required by post-catalyst monitor sensors to maintain a
sufficiently high temperature for accurate exhaust oxygen
content readings further from the engine.

Conditions for Setting the DTC

No related DTCs.

Engine coolant temperature is above 60

C (140

F).

The engine has been running for over 5 seconds.

Oxygen sensor heater is functioning properly.

Bank 2 HO2S 1 signal voltage remains between
400 mV and 500 mV for a total of 77 seconds over a
90-second period of time.

Action Taken When the DTC Sets

The PCM will ON the MIL after second trip with
detected fault.

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

“Open loop” fuel control will be in effect.

Conditions for Clearing the MIL/DTC

The PCM will turn the MIL “OFF” on the third
consecutive trip cycle during which the diagnostic has
been run and the fault condition is no longer present.

A history DTC P0154 will clear after 40 consecutive
warm-up cycles have occurred without a fault.

DTC P0154 can be cleared by using the Tech 2 “Clear
Info” function.

Diagnostic Aids

Check for the following conditions:

Poor connection or damaged harness – Inspect the
harness connectors for backed-out terminals,
improper mating, broken locks, improperly formed or

SECTION

6E–166

6VD1 3.2L ENGINE DRIVEABILITY AND EMISSIONS

damaged terminals, poor terminal-to-wire-connection,
and damaged harness.

Faulty HO2S heater or heater circuit – With the ignition
“ON”, engine “OFF”, the HO2S 1 voltage displayed on
the Tech 2 is normally 455-460 mV. A reading over
1000 mV indicates a signal line shorted to voltage. A
reading under 5 mV indicates a signal line shorted to
ground or signal lines shorted together. If not,
disconnect the HO2S and connect a test light between
the HO2S ignition feed and heater ground circuits. If
the test light does not light for 2 seconds when the
ignition is turned on, repair the open ignition feed or
sensor ground circuit as necessary. If the test light
lights and the HO2S signal and low circuits are OK,
replace the HO2S.

Intermittent test – With the ignition “ON”, monitor the
HO2S signal voltage while moving the wiring harness

and related connectors. If the fault is induced, the
HO2S signal voltage will change. This may help isolate
the location of the malfunction.

Test Description

Number(s) below refer to the step number(s) on the
Diagnostic Chart.
3. If the DTC P0154 test passes while the Failure

Records conditions are being duplicated, an
intermittent condition is indicated.

DTC P0154 –HO2S Circuit Insufficient Activity Bank 2 Sensor 1

Step

Action

Value(s)

Yes

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

—

Go to

Step 2

Go to

OBD

System

Check

1. Install the Tech 2.
2. Run the engine at operating temperature.
3. Operate the engine above 1200 RPM for two

minutes.

Does the Tech 2 indicate Bank 2 HO2S 1 voltage
varying outside the specified values?

400-500 mV

Go to

Step 3

Go to

Step 4

1. Ignition “ON”, engine “OFF”.
2. Review and record Tech 2 Failure Records data and

note parameters.

3. Operate the vehicle within Failure Records

conditions as noted.

4. Using a Tech 2, monitor “DTC” info for DTC P0154

until the DTC P0154 test runs.

5. Note the test result.

Does the Tech 2 indicate DTC P0154 failed this
ignition?

—

Go to

Step 4

Refer to

Diagnostic

Aids

Check for a damaged harness.

Was a problem found?

—

Verify repair

Go to

Step 5

Check for a poor Bank 2 HO2S 1 high and low circuit
terminal connections at the Bank 2 HO2S 1 harness
connector and replace terminal(s) if necessary.

Did any terminals require replacement?

—

Verify repair

Go to

Step 6

Check for a poor Bank 2 HO2S 1 high and low circuit
terminal connections at the PCM and replace
terminal(s) if necessary.

Did the terminal require replacement?

—

Verify repair

Go to

Step 7

1. Ignition “OFF”.
2. With the PCM disconnected, check continuity of the

Bank 2 HO2S 1 high circuit.

3. If the Bank 2 HO2S 1 high circuit measures over 5.0

ohms, repair open or poor connection as necessary.

Was a Bank 2 HO2S 1 high circuit problem found and
corrected?

—

Verify repair

Go to

Step 8

SECTION

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