Back OPEL FRONTERA 1998 Manual PDF

6E–115 ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0108 MAP Sensor Circuit High Voltage
D06RW102
Circuit Description
The manifold absolute pressure (MAP) sensor responds
to changes in intake manifold pressure (vacuum). The
MAP sensor signal voltage to the powertrain control
module (PCM) varies from below 2 volts at idle (high
vacuum) to above 4 volts with the key “ON,” engine not
running or at wide-open throttle (low vacuum).
The MAP sensor is used to determine manifold pressure
changes while the linear EGR flow test diagnostic is being
run (refer to
DTC P0401), to determine engine vacuum
level for some other diagnostics and to determine
barometric pressure (BARO). The PCM monitors the
MAP signals for voltages outside the normal range of the
MAP sensor. If the PCM detects a MAP signal voltage
that is excessively high, DTC P0108 will be set.
Conditions for Setting the DTC
No TP sensor DTCs present.
Engine is running for more than 10 seconds.
Throttle position is below 3% if engine speed is below
1000 RPM.
Throttle position is below 10% if engine speed is above
1000 RPM.
The MAP sensor indicates an intermittent manifold
absolute pressure above 80kPa for a total of
approximately 10 seconds over a 16-second period.
Action Taken When the DTC Sets
The PCM will illuminate the malfunction indicator lamp
(MIL) the first time the fault is detected.
The PCM will default to a BARO value of 79.3 kPa.
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 P0108 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
MAP display on the Tech 2 while moving connectors
and wiring harnesses related to the sensor. A change
in the display will indicate the location of the fault.
If DTC P0108 cannot be duplicated, the information
included in the Failure Records data can be useful in
determining vehicle mileage since the DTC was last set. If
it is determined that the DTC occurs intermittently,
performing the DTC P1108 Diagnostic Chart may isolate
the cause of the fault.

6E–118
ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0112 IAT Sensor Circuit Low Voltage
D06RW026
Circuit Description
The intake air temperature (IAT) sensor is a thermistor
which measures the temperature of the air entering the
engine. The powertrain control module (PCM) applies 5
volts through a pull-up resistor to the IAT sensor. When
the intake air is cold, the sensor resistance is high and the
PCM will monitor a high signal voltage on the IAT signal
circuit. If the intake air is warm, the sensor resistance is
lower, causing the PCM to monitor a lower voltage. DTC
P0112 will set when the PCM detects an excessively low
signal voltage on the intake air temperature sensor signal
circuit.
Conditions for Setting the DTC
The engine has been running for over 2 minutes.
Vehicle speed is greater than 30 mph (48 km/h) .
IAT signal voltage indicates and intake air temperature
greater than 148C (298F) (about 5 volts) for a total
of 12.5 seconds over a 25-second period of time.
Action Taken When the DTC Sets
The PCM will illuminate the malfunction indicator lamp
(MIL) the first time 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 P0112 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-bout 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
IAT display on the Tech 2 while moving connectors and
wiring harnesses related to the IAT sensor. A change
in the IAT display will indicate the location of the fault.
If DTC P0112 cannot be duplicated, the information
included in the Failure Records data can be useful in
determining vehicle mileage since the DTC was last set.
Test Description
Number(s) below refer to the step number(s) on the
Diagnostic Chart:
2. Verifies that the fault is present.

6E–121 ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0113 IAT Sensor Circuit High Voltage
D06RW026
Circuit Description
The intake air temperature (IAT) sensor is a thermistor
which measures the temperature of the air entering the
engine. The powertrain control module (PCM) applies 5
volts through a pull-up resistor to the IAT sensor. When
the intake air is cold, the sensor resistance is high and the
PCM will monitor a high signal voltage on the IAT signal
circuit. If the intake air is warm, the sensor resistance is
lower causing the PCM to monitor a lower voltage. DTC
P0113 will set when the PCM detects an excessively high
signal voltage on the intake air temperature sensor signal
circuit.
Conditions for Setting the DTC
The engine has been running for over 4 minutes.
Vehicle speed is less than 20 mph (32 km/h).
ECT signal temperature is above 60C (140F).
Mass air flow is less then 20 g/second.
IAT signal voltage indicates an intake air temperature
less than –39C (–38F) for total of 12.5 seconds over
a 25-second period.
Action Taken When the DTC Sets
The PCM will illuminate the malfunction indicator lamp
(MIL) the first time 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 P0113 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:
The IAT sensor shares a ground with the EGR position
sensor and the TP sensor. Check the ground if these
DTC’s are set.
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
IAT display on the Tech 2 while moving connectors and
wiring harnesses related to the IAT sensor. A change
in the IAT display will indicate the location of the fault.
If DTC P0113 cannot be duplicated, the information
included in the Failure Records data can be useful in
determining vehicle mileage since the DTC was last set.
Test Description
Number(s) below refer to the step number(s) on the
Diagnostic Chart:
2. Verifies that the fault is present.

6E–124
ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0117 ECT Sensor Circuit Low Voltage
060RY00304
Circuit Description
The engine coolant temperature (ETC) sensor is a
thermistor mounted on a coolant crossover pipe at the
rear of the engine. The powertrain control module (PCM)
applies a voltage (about 5 volts) through a pull-up resistor
to the ECT signal circuit. When the engine coolant is cold,
the sensor (thermistor) resistance is high, therefore the
PCM will measure a high signal voltage. As the engine
coolant warms, the sensor resistance becomes lower,
and the ECT signal voltage measured at the PCM drops.
With a fully warmed-up engine, the ECT signal voltage
should measure about 1.5 to 2.0 volts.
Conditions for Setting the DTC
Engine running time is longer than one minute.
The ECT sensor signal indicates an engine coolant
temperature greater than 150C (302F) (about 0.10
V) for a total of 50 seconds over a 100–second period.
Action Taken When the DTC Sets
The PCM will illuminate the malfunction indicator lamp
(MIL) the first time the fault is detected.
The PCM will substitute the ECT reading with a default
engine coolant temperature value. The default value
is based on start-up intake air temperature and running
time.
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 P0117 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
ECT display on the Tech 2 while moving connectors
and wiring harnesses related to the ECT sensor. A
change in the ECT display will indicate the location of
the fault.
If DTC P0117 cannot be duplicated, the information
included in the Failure Records data can be useful in
determining vehicle mileage since the DTC was last set.
Test Description
Number(s) below refer to the step number(s) on the
Diagnostic Chart.

6E–127 ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0118 ECT Sensor Circuit High Voltage
060RY00304
Circuit Description
The engine coolant temperature (ETC) sensor is a
thermistor mounted in on a coolant crossover pipe at the
rear of the engine. The powertrain control module (PCM)
applies a voltage (about 5 volts) through a pull-up resistor
to the ECT signal circuit. When the engine coolant is cold,
the sensor (thermistor) resistance is high, therefore the
PCM will measure a high signal voltage. As the engine
coolant warms, the sensor resistance becomes less, and
the ECT signal voltage measured at the PCM drops. With
a fully warmed-up engine, the ECT signal voltage should
measure about 1.5 to 2.0 volts.
Conditions for Setting the DTC
Engine running time is longer than 1.5 minutes.
The ECT sensor signal indicates an engine coolant
temperature of –39C (–38F) or less (about 5 volts)
for a total of 50 seconds over a 100-second period.
Action Taken When the DTC Sets
The PCM will illuminate the malfunction indicator lamp
(MIL) the first time the fault is detected.
The PCM will substitute the ECT reading with a default
engine coolant temperature value. The default value
is based on start-up intake air temperature and running
time.
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 P0118 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:
The ECT shares a ground with the Transmission Fluid
Temperature sensor, the Rough Road sensor, and the
MAP sensor.
Check the ground if these DTCs are also set.
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
ECT display on the Tech 2 while moving connectors
and wiring harnesses related to the ECT sensor. A
change in the ECT display will indicate the location of
the fault.
If DTC P0118 cannot be duplicated, the information
included in the Failure Records data can be useful in
determining vehicle mileage since the DTC was last set.
If it is determined that the DTC occurs intermittently,
performing the DTC P1115 Diagnostic Chart may isolate
the cause of the fault.

6E–130
ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0121 TP System Performance
D06RW028
Circuit Description
The throttle position (TP) sensor circuit provides a voltage
signal that changes relative to throttle blade angle. The
signal voltage will vary from about 0.6 volts at closed
throttle to about 4.5 volts at wide open throttle (WOT).
The TP signal is used by the powertrain control module
(PCM) for fuel control and many of the PCM-controlled
outputs. The PCM monitors throttle position and
compares actual throttle position from the TP sensor to a
predicted TP value calculated from engine speed. If the
PCM detects an out-of-range condition, DTC P0121 will
set.
Conditions for Setting the DTC
The engine is running.
No MAP DTCs, or P0121, P0122, P0123 are set.
MAP reading is below 55 kPa.
Throttle is steady, throttle angle is changing less than
1%.
Predicted throttle angle is not close to actual throttle
angle.
Above conditions are present for a total of 12.5
seconds over a 25-second period of time.
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.
The PCM will use a default throttle position based on
mass air flow and RPM.
Conditions for Clearing the MIL/DTC
DTC P0121 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:
Skewed MAP signal or faulty Map sensor – An
incorrect MAP signal may cause the PCM to incorrectly
calculate the predicted TP sensor value during high
engine load situations. Check for an unusually low
MAP reading. This condition can cause DTC P0121 to
be set.
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
ECT display on the Tech 2 while moving connectors
and wiring harnesses related to the sensor. A change
in the display will indicate the location of the fault.
If DTC P0121 cannot be duplicated, the information
included in the Failure Records data can be useful in
determining vehicle mileage since the DTC was last set.

6E–133 ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0122 TP Sensor Circuit Low Voltage
D06RW028
Circuit Description
The throttle position (TP) sensor circuit provides a voltage
signal that changes relative to throttle blade angle. The
signal voltage will vary from below 0.6 volts at closed
throttle to about 4.5 volts at wide open throttle (WOT).
The TP signal is used by the powertrain control module
(PCM) for fuel control and many of the PCM–controlled
outputs.
Conditions for Setting the DTC
The ignition is “ON.”
TP sensor signal voltage is less than 0.22 volt for a total
of 0.78 second over a 1.5-second period.
Action Taken When the DTC Sets
The PCM will illuminate the malfunction indicator lamp
(MIL) the first time 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.
The PCM will use a default throttle position based on
mass air flow and RPM.
Conditions for Clearing the MIL/DTC
DTC P0122 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:
Check intermittent codes.
The TP sensor shares a 5 Volt reference with the EGR
position sensor. Check the 5 Volt reference if these
DTCs are also set.
The TP sensor shares a ground with the IAT sensor,
the EGR position sensor.
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
throttle position display on the Tech 2 while moving
connectors and wiring harnesses related to the TP
sensor. A change in the display will indicate the
location of the fault.
If DTC P0122 cannot be duplicated, the information
included in the Failure Records data can be useful in
determining vehicle mileage since the DTC was last set.

6E–136
ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0123 TP Sensor Circuit High Voltage
D06RW028
Circuit Description
The throttle position (TP) sensor circuit provides a voltage
signal that changes relative to throttle blade angle. The
signal voltage will vary from about 0.6 volts at closed
throttle to about 4.5 volts at wide open throttle (WOT).
The TP signal is one of the most important inputs used by
the powertrain control module (PCM) for fuel control and
many of the PCM-controlled outputs.
Conditions for Setting the DTC
The ignition is “ON.”
TP sensor signal voltage is greater than 4.88 volts for
a total of 0.78 second over a 1.5-second period.
Action Taken When the DTC Sets
The PCM will illuminate the malfunction indicator lamp
(MIL) the first time 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.
The PCM will use a default throttle position based on
mass air flow and RPM.
Conditions for Clearing the MIL/DTC
DTC P0123 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:
Check intermittent codes.
The TP sensor shares a 5 Volt reference with the EGR
position sensor. Check the 5 Volt reference if these
DTCs are also set.
The TP sensor shares a ground with the IAT sensor
and the EGR position sensor. Check the ground if
these other DTCs are also set.
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
TP sensor display on the Tech 2 while moving
connectors and wiring harnesses related to the TP
sensor. A change in the display will indicate the
location of the fault.
Faulty TP sensor – With the ignition key “ON,” engine
“OFF,” observe the TP sensor display on the Tech 2
while slowly depressing the accelerator to wide open
throttle. If a voltage over 4.88 volts is seen at any point
in normal accelerator travel, replace the TP sensor.
If DTC P0123 cannot be duplicated, the information
included in the Failure Records data can be useful in
determining vehicle mileage since the DTC was last set.
Test Description
Number (s) below refer to the step number(s) on the
Diagnostic Chart.
7. Components that share the TP sensor 5 volt reference
“A” circuit include the following device:
EGR valve

6E–145 ENGINE DRIVEABILITY AND EMISSIONS
D i a g n o s t i c Tr o u b l e C o d e ( D T C ) P 0 1 3 4 H O 2 S C i r c u i t I n s u f f i c i e n t Activity Bank 1
Sensor 1
060RW237
Circuit Description
The powertrain control module (PCM) supplies a bias
voltage of about 450 mV between the heated oxygen
s e n s o r ( H O 2 S ) h i g h a n d l o w c i r c u i t s . W h e n m e a s u r e d
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 1 HO2S 1 voltage remains at or near the 450 mV
bias for an extended period of time, DTC P0134 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.
Battery voltage is above 10 volts.
Engine run time is longer than 40 seconds.
Oxygen sensor heater has been determined to be
functioning properly.
Bank 1 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 Take When the DTC Sets
The PCM will illuminate the malfunction indicator lamp
(MIL) the first time 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.
“Open loop” fuel control will be in effect.
Conditions for Clearing the MIL/DTC
DTC P0134 can be cleared by using Tech 2 “Clear Info”
function or by disconnecting the PCM battery feed.
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
damaged terminals, poor terminal-to-wire connection,
and damaged harness.
Faulty HO2S heater or heater circuit – With the ignition
“ON,” engine “OFF,” after a cool down period, the
HO2S 1 voltage displayed on Tech 2 is normally
455-460 mV. A reading over 1000 mV indicates a
signal line shorted to voltage. A reading under 5 mV

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.