Opel Frontera UBS. Manual - part 2297

6E–224

6VE1 3.5 ENGINE DRIVEABILITY AND EMISSIONS

Diagnostic Trouble Code (DTC) 

P0175 Fuel Trim System Rich Bank 2

D06R200010

Circuit Description

To provide the best possible combination of driveability,
fuel economy, and emission control, a “closed loop”
air/fuel metering system is used.  While in “closed loop”,
the powertrain control module (PCM) monitors the Bank 1
HO2S 1 and Bank 2 HO2S 1 signals and adjusts fuel
delivery based upon the HO2S signal voltages.  A change
made to fuel delivery will be indicated by the long and
short term fuel trim values which can be monitored with a
Tech 2.  Ideal fuel trim values are around 0%; if the HO2S
signals are indicating a lean condition the PCM will add
fuel, resulting in fuel trim values above 0%.  If a rich
condition is detected, the fuel trim values will be below
0%, indicating that the PCM is reducing the amount of fuel
delivered.  If an excessively rich condition is detected on
Bank 2, the PCM will set DTC P0175.
The PCM’s maximum authority to control long term fuel
trim allows a range between –15%(automatic
transmission) or –12%(manual transmission) and +20%.
The PCM’s maximum authority to control short term fuel
trim allows a range between –11% and +20%.  The PCM
monitors fuel trim under various engine speed/load fuel
trim cells before determining the status of the fuel trim
diagnostic.

Conditions for Setting the DTC

D

None of the following DTCs are set: idle system, EGR,
HO2S, (response, transition, open, low volts, no

activity), MAF, TPS, MAP, IAT, canister purge, EVAP,
injector circuit, or misfire.

D

Engine coolant temperature is between 6

°

C (42.8

°

F)

and 105

°

C (221

°

F).

D

Intake air temperature is between –40

°

C (–40

°

F) and

120

°

C (248

°

F).

D

Manifold absolute pressure is between 24 kPa and 99
kPa.

D

Throttle angle is steady between 3 and 95%.

D

Vehicle speed is below 136 km/h (85 mph).

D

Engine speed is between 400 and 6,000 RPM.

D

Barometric pressure is greater than 72.5 kPa.

D

Mass air flow is between 2 g/second and 200 g/second.

D

Ignition voltage is above 9.5 volts.

D

Fuel system is in “closed loop”.

Action Taken When the DTC Sets

D

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

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

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.

6E–225

6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS

D

A history DTC P0175 will clear after 40 consecutive
warm-up cycles have occurred without a fault.

D

DTC P0175 can be cleared by using the Tech 2 “Clear
Info” function or by disconnecting the PCM battery
feed.

Diagnostic Aids

Check for the following conditions:

D

Poor connection at PCM – Inspect harness connectors
for backed -out terminals, improper mating, broken
locks, improperly formed or damaged terminals, and
poor terminal-to-wire connection.

D

Damaged harness – Inspect the wiring harness for
damage.  If the harness appears to be OK, observe the
Bank 2 HO2S 1 display on the Tech 2 while moving
connectors and wiring harnesses related to the engine
harness.  A change in the display will indicate the
location of the fault.

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.

Test Description

Number(s) below refer to the step number(s) on the
Diagnostic Chart.
2. DTCs other than P0172 and P0175 may indicate a

condition present which may cause a lean condition.
If this is the case, repairing the condition which
caused the other DTC will most likely correct the
DTC P0172/P0175.

4. If the DTC P0175 test passes while the Failure

Records conditions are being duplicated, the rich
condition is intermittent.  Refer to 

Diagnostic Aids or

Symptoms for additional information on diagnosing
intermittent problems.

DTC P0175 – Fuel Trim System Rich Bank 2

 

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

Are any DTCs set other than P0172 and P0175?

—

Go to the

applicable

DTC charts

and repair the

other DTCs

before

proceeding

with this

chart.

Go to 

Step 3

3

1. Start the engine and operate the vehicle in “closed

loop”.

2. Observe the “BANK 2 L.T. FUEL TRIM” display on

the Tech 2.

Is the displayed value more negative than the specified
value?

L.T. Fuel

Trim: –15%

(auto. trans.)

OR –12%

(man. trans.)

Go to 

Step 5

Go to 

Step 4

4

1. Review and record the Tech 2 Failure Records data.
2. Clear the DTC P0172/P0175 and operate the

vehicle to duplicate the Failure Records conditions.

3. Monitor the Tech 2 “DTC” info for DTC P0175 while

operating the vehicle to duplicate the Failure
Records conditions.

4. Continue operating the vehicle until the DTC P0175

test runs.

5. Note the test result.

Does the Tech 2 indicate DTC P0175 failed this
ignition?

—

Go to 

Step 5

The rich

condition is

not present.

If a

driveability

symptom still

exists, refer

to 

Symptoms.

5

Was DTC P0172 also set?

—

Go to 

Step 6

Go to 

Step 15

6

Visually and physically inspect the air filter element and
replace it if necessary.

Did the air filter require replacement?

—

Verify repair

Go to 

Step 7

6E–226

6VE1 3.5 ENGINE DRIVEABILITY AND EMISSIONS

DTC P0175 – Fuel Trim System Rich Bank 2

  (Cont'd)

Step

No

Yes

Value(s)

Action

7

Visually and physically inspect the air intake duct for
collapse or restriction and repair if necessary.

Did your inspection reveal a problem requiring repair?

—

Verify repair

Go to 

Step 8

8

Inspect the MAF sensor inlet screen for damage or for
the presence of foreign objects which may partially
block air flow through the screen and correct any
problem found.

Did your inspection of the MAF sensor reveal a
condition requiring repair or replacement?

—

Verify repair

Go to 

Step 9

9

Start the engine and note the idle quality.

Is a low or unsteady idle being experienced?

—

Go to 

Step 10

Go to 

Step 11

10

1. Turn the ignition off and physically inspect the

throttle body bore, throttle plate, and IAC passages
for coking and foreign objects.

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

Did your inspection reveal a condition requiring repair?

—

Verify repair

Go to 

Step 11

11

1. Disconnect the vacuum hose from the fuel pressure

regulator and inspect the hose for the presence of
fuel.

2. If fuel is present in the vacuum hose, replace the

fuel pressure regulator (refer to 

Fuel Metering

System).

Did the fuel pressure regulator require replacement?

—

Verify repair

Go to 

Step 12

12

1. Ignition “ON”, engine “OFF”.
2. Monitor the TP Angle display on the Tech 2 while

slowly depressing the accelerator pedal.

Does the TP Angle display increase steadily and
evenly from minimum value at closed throttle to
maximum value at wide-open throttle?

Minimum 8%

Maximum

92%

Go to 

Step 13

Go to 

Step 21

13

1. Disconnect the MAF sensor electrical connector.
2. Operate the vehicle in “closed loop” while

monitoring the “BANK 2 L.T. FUEL TRIM” and
“BANK 2 S.T. FUEL TRIM” display on the Tech 2.

Did both values change to near the specified value?

0%

Go to 

Step 22

Go to 

Step 14

14

1. Perform the “Fuel System Pressure Test”.
2. If Fuel System Pressure Test isolates a problem,

repair as necessary (refer to 

Engine Fuel or Fuel

Metering System).

Did the Fuel System Pressure Test isolate a condition
requiring repair?

—

Verify repair

Go to 

Step 15

15

1. Ignition “ON”, engine “OFF”.
2. Connect a test light between the harness connector

terminals of canister purge solenoid.

Is the test light on?

—

Go to 

Step 16

Go to 

Step 19

16

Check for short to ground in the wire (YEL/RED)
between the canister purge solenoid and PCM terminal
S-48.

Was there a short to ground?

—

Go to 

Step 17

Go to 

Step 18

6E–227

6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS

DTC P0175 – Fuel Trim System Rich Bank 2

  (Cont'd)

Step

No

Yes

Value(s)

Action

17

Repair the short to ground.

Is the action complete?

—

Verify repair

—

18

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 the 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

—

19

1. Perform the “Injector Balance Test”.
2. If the Injector Balance Test isolates a problem,

repair as necessary (refer to 

Fuel Metering

System).

Did the Injector Balance Test isolate a problem
requiring repair?

—

Verify repair

Go to 

Step 20

20

1. Remove and visually/physically inspect the Bank 2

HO2S 1 for silicon contamination.  This will be
indicated by a powdery deposit on the portion of the
HO2S that is exposed to the exhaust stream.

2. If contamination is evident on the Bank 2 HO2S 1,

replace the contaminated sensor.

Did the sensor require replacement?

—

Verify repair

Check the

Procedure

Refer to

Diagnostic

Aids

21

1. Check the TP sensor mounting screws and tighten

or replace them as necessary if they are loose or
missing.

2. If the screws are OK, replace the TP sensor.

Is the action complete?

—

Verify repair

—

22

Replace the MAF sensor.

Is the action complete?

—

Verify repair

—