1998 OPEL FRONTERA ignition

6E–146
ENGINE DRIVEABILITY AND EMISSIONS
indicates a signal line shorted to ground or signal lines
shorted together. 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 P0134 test passes while the Failure
Records conditions are being duplicated, an
intermittent conditions 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 P0134 –HO2S Circuit Insufficient Activity Bank 1 Sensor 1
StepActionVa l u e ( s )Ye sNo
1Was the “On-Board Diagnostic (OBD) System Check”
performed?
—Go to Step 2
Go to OBD
System
Check
21. Install Tech 2.
2. Run the engine at operating temperature.
3. Operate the engine above 1200 RPM for two
minutes.
Does Tech 2 indicate Bank 1 HO2S 1 voltage varying
outside the specified values?
400-500 mVGo to Step 3Go to Step 4
31. Ignition “ON,” engine “OFF,” review and record Tech
2 Failure Records data and note parameters.
2. Operate the vehicle within Failure Records
conditions as noted.
3. Using Tech 2, monitor “Specific DTC” info for DTC
P0134 until the DTC P0134 test runs.
4. Note the test result.
Does Tech 2 indicate DTC P0134 failed this ignition?
—Go to Step 4
Refer to
Diagnostic
Aids
4Check for a damaged harness.
Was a problem found?
—Verify repairGo to Step 5
5Check for poor Bank 1 HO2S 1 high and low circuit
terminal connections at the Bank 1 HO2S 1 harness
connector and replace terminal(s) if necessary.
Did any terminals require replacement?
—Verify repairGo to Step 6
6Check for poor Bank 1 HO2S 1 high and low circuit
terminal connections at the PCM and replace terminals
if necessary.
Did any terminals require replacement?
—Verify repairGo to Step 7
71. Ignition “OFF.”
2. With the PCM disconnected, check continuity of the
Bank 1 HO2S 1 high circuit.
3. If the Bank 1 HO2S 1 high circuit measures over 5.0
ohms, repair open or poor connection as necessary.
Was a Bank 1 HO2S 1 high circuit problem found and
corrected?
—Verify repairGo to Step 8

6E–147 ENGINE DRIVEABILITY AND EMISSIONS
DTC P0134 –HO2S Circuit Insufficient Activity Bank 1 Sensor 1
StepNo Ye s Va l u e ( s ) Action
81. Ignition “OFF.”
2. With the PCM disconnected, check continuity of the
Bank 1 HO2S 1 low circuit.
3. If the Bank 1 HO2S 1 low circuit measures over 5
ohms, repair open or poor connection as necessary.
Was a Bank 1 HO2S 1 low circuit problem found and
corrected?
—Verify repairGo to Step 9
91. Ignition “ON,” engine “OFF.”
2. Disconnect Bank 1 HO2S 1 and jumper the HO2S
high and low circuits (PCM side) to ground.
3. Using Tech 2, monitor Bank 1 HO2S 1 voltage.
Is Bank 1 HO2S 1 voltage in the specified range?
0-10 mVGo to Step 10Go to Step 11
10Replace Bank 1 HO2S 1.
Is the action complete?
—Verify repair—
11Replace the PCM.
IMPORTANT:The replacement PCM must be
programmed. Refer to
UBS 98model year Immobilizer
Workshop Manual.
Is the action complete?—Verify repair—

6E–149 ENGINE DRIVEABILITY AND EMISSIONS
exhaust leaks that may cause a false lean condition to
be indicated.
MAF sensor –The system can go lean if the MAF
sensor signal indicates an engine airflow
measurement that is not correct. Disconnect the MAF
sensor to see if the lean condition is corrected. If so,
replace the MAF sensor.
Fuel contamination – Water, even in small amounts,
can be delivered to the fuel injectors. The water can
cause a lean exhaust to be indicated. Excessive
alcohol in the fuel can also cause this condition. Refer
to
Fuel System Diagnosis for the procedure to check
for fuel contamination.
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 P0151 failing during operation may indicate a
condition described in the “Diagnostic Aids” above.
If the DTC P0151 test passes while the Failure
Records conditions are being duplicated, an
intermittent condition is indicate.
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 P0151 – HO2S Circuit Low Voltage Bank 2 Sensor 1
StepActionVa l u e ( s )Ye sNo
1Was the “On-Board Diagnostic (OBD) System Check”
performed?
—Go to Step 2
Go to OBD
System
Check
21. Install Tech 2.
2. Run the engine at operating temperature.
3. Operate the vehicle within the parameters specified
under “Conditions for Setting the DTC” criteria
included in Diagnostic Support.
4. Using Tech 2, monitor Bank 2 HO2S 1 voltage.
Does the Bank 2 HO2S 1 voltage remain below the
specified value?
22 mVGo to Step 4Go to Step 3
31. Ignition “ON,” engine “OFF,” review and record Tech
2 Failure Records data and note parameters.
2. Operate the vehicle within Failure Records
conditions as noted.
3. Using Tech 2, monitor “Specific DTC” info for DTC
P0151 until the DTC P0151 test runs.
4. Note test result.
Does Tech 2 indicate DTC P0151 failed this ignition?
—Go to Step 4
Refer to
Diagnostic
Aids
41. Turn ignition “OFF.”
2. Disconnect the PCM.
3. Check the Bank 2 HO2S 1 high and low signal
circuits for a short to ground or a short to the heater
ground circuit.
Were Bank 2 HO2S 1 signal circuits shorted?
—Go to Step 5Go to Step 6
5Repair the Bank 2 HO2S 1 signal circuit.
Is the action complete?
—Verify repair—
61. Ignition “OFF.”
2. Leave the PCM and HO2S 1 disconnected.
3. Check for continuity between the high and low
signal circuits.
Was there continuity between the high and low circuits?
—Go to Step 7Go to Step 8
7Repair the short between the high and low circuits.
Is the action complete?
—Verify repair—

6E–150
ENGINE DRIVEABILITY AND EMISSIONS
DTC P0151 – HO2S Circuit Low Voltage Bank 2 Sensor 1
StepNo Ye s Va l u e ( s ) Action
81. Ignition “OFF.”
2. Reconnect the PCM, leave HO2S 2 disconnected.
3. Ignition “ON.”
Does Tech 2 indicate Bank 2 HO2S 1 voltage near the
specified value?
425-475 mV
Refer to
Diagnostic
Aids
Go to Step 9
9Replace the PCM.
IMPORTANT:The replacement PCM must be
programmed. Refer to
UBS 98model year Immobilizer
Workshop Manual.
Is the action complete?—Verify repair—

6E–152
ENGINE DRIVEABILITY AND EMISSIONS
MAF sensor – The system can go rich if the MAF
sensor signal indicates an engine airflow
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
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 450mV, replace the HO2S. Silicon
contamination of the HO2S can cause a high HO2S
voltage to be indicated. This condition is indicated by
powdery white 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 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
StepActionVa l u e ( s )Ye sNo
1Was the “On-Board Diagnostic (OBD) System Check”
performed?
—Go to Step 2
Go to OBD
System
Check
21. Install 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 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 4Go to Step 3
31. Ignition “ON.”
2. Review and record Tech 2 Failure Records data.
3. Operate the vehicle within Failure Records
conditions as noted.
4. Using Tech 2, monitor “Specific DTC” info for DTC
P0152 until the DTC P0152 test runs.
5. Note the test result.
Does Tech 2 indicate DTC P0152 failed this ignition?
—Go to Step 4
Refer to
Diagnostic
Aids
41. 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 VGo to Step 5Go to Step 6
5Repair short to voltage in signal circuit.
Is the action complete?
—Verify repair—

6E–153 ENGINE DRIVEABILITY AND EMISSIONS
DTC P0152 – HO2S Circuit High Voltage Bank 2 Sensor 1
StepNo Ye s Va l u e ( s ) Action
61. 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 Tech 2, monitor Bank 2 HO2S 1 voltage.
Is Bank 2 HO2S 1 voltage below the specified value?
10 mVGo to Step 7Go to Step 8
71. 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
8Replace the PCM.
IMPORTANT:The replacement PCM must be
programmed. Refer to
UBS 98model year Immobilizer
Workshop Manual.
Is the action complete?—Verify repair—

6E–155 ENGINE DRIVEABILITY AND EMISSIONS
Mass air flow is between 2 g/second and 200 g/second.
Ignition voltage is above 9.5 volts.
Fuel system is in “closed loop.”
Action Taken When the DTC Sets
The PCM will illuminate the malfunction indicator lamp
(MIL) after the second consecutive trip in which the
fault is detected.
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
DTC P0171 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:
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.
Damaged harness – Inspect the wiring harness for
damage. If the harness appears to be OK, observe the
Bank 1 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 P0171 and P0174 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 P0171/P0174.
4. If the DTC P0171 test passes while the Failure
Records conditions are being duplicated, the lean
condition is intermittent. Refer to
Diagnostic Aids or
Symptoms for additional information on diagnosing
intermittent problems.

6E–156
ENGINE DRIVEABILITY AND EMISSIONS
DTC P0171 – Fuel Trim System Lean Bank 1
StepActionVa l u e ( s )Ye sNo
1Was the “On-Board Diagnostic (OBD) System Check”
performed?
—Go to Step 2
Go to OBD
System
Check
2Are any DTCs set other than P0171 and P0174?
—
Go to the
applicable
DTC charts
and repair the
other DTCs
before
proceeding
with this chart
Go to Step 3
31. Start the engine and operate the vehicle in “closed
loop.”
2. Observe the “BANK 1 L.T. FUEL TRIM” display on
the Tech 2.
Is the displayed value greater than the specified value?
L.T. Fuel
Trim: +20%
Go to Step 5Go to Step 4
41. Review and record the Tech 2 Failure Records data.
2. Clear the DTC P0171/P0174 and operate the
vehicle to duplicate the Failure Records conditions.
3. Monitor the Tech 2 “Specific DTC” info for DTC
P0171 while operating the vehicle to duplicate the
Failure Records conditions.
4. Continue operating the vehicle until the DTC P0171
test runs and note the test result.
Does the Tech 2 indicate DTC P0171 failed this
ignition?
—Go to Step 5
The lean
condition is
not present.
If a
driveability
symptom still
exists, refer
to
Symptoms
section.
5Was DTC P0174 also set?—Go to Step 6Go to Step 15
6Visually and physically inspect the vacuum hoses for
disconnects, splits, kinks, improper routing and
improper connections and repair any problem found.
Did your inspection reveal a problem requiring repair?
—Verify repairGo to Step 7
7Visually and physically inspect the crankcase
ventilation valve for proper installation and repair any
problem found (refer to
Crankcase Ventilation
System
).
Did your inspection reveal a problem requiring repair?
—Verify repair Go to Step 8
81. Inspect the MAF sensor inlet screen for damage or
for the presence of foreign objects which may
partially block the air flow sample through the MAF
sensor.
2. Correct any problem that is found as necessary.
Did your inspection of the MAF sensor reveal a
condition requiring repair?
—Verify repairGo to Step 9
9Start the engine and note the idle quality.
Is a high or unsteady idle being experienced?
—Go to Step 10Go to Step11
101. Visually and physically inspect the throttle body,
intake manifold, EGR valve and the EGR feed pipe
for vacuum leaks.
2. Repair any vacuum leaks as necessary.
Did your inspection reveal a vacuum leak?
—Verify repair Go to Step 11