1998 OPEL FRONTERA check engine light

6E–137 ENGINE DRIVEABILITY AND EMISSIONS
Disconnect the component while observing the TP
sensor display on the Tech 2. If the reading
changes drastically when this component isdisconnected, replace the component that affected
the reading.
DTC P0123 – TP Sensor Circuit High Voltage
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. Ignition “ON,” engine “OFF.”
2. With the throttle closed, observe the “TP Sensor”
display on the Tech 2.
Is the “TP Sensor” above the specified value?
4.88 VGo to Step 4Go to Step 3
31. Ignition “ON,” engine “OFF.”
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 “Specific DTC” info for DTC
P0123.
Does the Tech 2 indicate DTC P0123 failed.
—Go to Step 4
Refer to
Diagnostic
Aids
41. Disconnect the TP sensor electrical connector.
2. Observe the “TP Sensor” display on the Tech 2.
Is the “TP Sensor” near the specified value?
0 VGo to Step 5Go to Step 6
5Probe the sensor ground circuit at the TP sensor
harness connector with a test light connected to B+.
Is the test light “ON?”
—Go to Step 7Go to Step 10
61. Ignition “OFF,” disconnect the PCM.
2. Ignition “ON,” engine “OFF.”
3. Check for a short to voltage on the TP sensor signal
circuit.
4. If the TP sensor signal circuit is shorted, repair it as
necessary.
Was the TP sensor signal circuit shorted?
—Verify repairGo to Step 12
71. Ignition “ON.”
2. Monitor the “TP Sensor” Tech 2 display while
disconnecting each of the components that share
the 5 volt reference “A” circuit (one at a time).
3. If the “TP Sensor” Tech 2 display changes, replace
the component that caused the display to change
when disconnected.
Does disconnecting any of these components cause
the “TP Sensor” display to change?
—Verify repairGo to Step 8
81. Ignition “OFF,” disconnect the PCM.
2. Ignition “ON,” engine “OFF.”
3. Check for a short to B+ on the 5 volt reference “A”
circuit.
4. If the 5 volt reference “A” circuit is shorted, repair it
as necessary.
Was the 5 volt reference “A” circuit shorted?
—Verify repairGo to Step 9
9Check for poor electrical connections at the TP sensor
and replace terminals if necessary.
Did any terminals require replacement?
—Verify repairGo to Step 11

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–170
ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0201 Injector 1 Control Circuit
D06RW034
Circuit Description
The powertrain control module (PCM) has six individual
injector driver circuits. Each controls an injector. When a
driver circuit is grounded by the PCM, the injector is
activated. The PCM monitors the current in each driver
circuit. The voltage on each driver is monitored to detect
a fault. If the voltage is not what the PCM expects to
m o n i t o r o n t h e c i r c u i t , a D T C i s s e t . T h i s D T C i s a l s o s e t i f
an injector driver is shorted to voltage or if there is an open
circuit.
Conditions for Setting the DTC
The battery voltage is more than 9 volts.
The engine is turning, determined by 58X crankshaft
position input signal.
The injector voltage does not equal the ignition voltage
when the injector is commanded “OFF” or the injector
voltage does not equal 0 volts when the injector is
commanded “ON.”
The above conditions are met for 15 seconds.
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 P0201 can be cleared by using the Tech 2 “Clear
Info” function or by disconnecting the PCM battery
feed.
Diagnostic Aids
An injector driver circuit that is open or shorted to voltage
will cause a DTC P0201 to set. It will also cause a misfire
due to an inoperative injector. A misfire DTC will also be
set indicating which cylinder is inoperative.
Long term and short term fuel trims that are excessively
high or low are a good indication that an injector is faulty.
Use Fuel Injector Coil Test Procedure to check for faulty
injectors.
Test Description
The number(s) below refer to the step number(s) on the
Diagnostic Chart.
3. This step determines if DTC P0201 is the result of a
hard failure or an intermittent condition.
5. A special injector test connector is provided so that
the injectors can be electrically tested without
removal of the manifold. On the Trooper, the
special 7-way gray connector is located at the front
of the charcoal canister. The test connector can be
identified by the blue connector lock which is
tethered to the wiring harness. If the light for
cylinder 1 is “ON” steady before cranking the engine
as well as while cranking the engine, then the
injector driver circuit is shorted to ground.

6E–171 ENGINE DRIVEABILITY AND EMISSIONS
If the test light blinks while cranking, the PCM and
the wiring to the injectors are OK. The Fuel Injector
Coil Test Procedure will check if the injectors are
faulty.
R321054
7. Because the test light was “ON” steady, voltage to
the injector is OK, but the driver circuit is grounded
at all times. This step determines if the circuit is
shorted to ground or the PCM is faulty.
9. The reading should be about 12-14
.
10.Locating the open in the harness or in the injector
will require removal of the manifold to provide
access.
DTC P0201 – Injector 1 Control Circuit
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
2Will the engine start?
—Go to Step 3
Go to Engine
Cranks But
Will Not Run
chart
31. Install the Tech 2. Clear the DTC.
2. Idle the engine for one minute.
Does DTC P0201 reset?
—Go to Step 5Go to Step 4
41. Review the Freeze Frame data with the ignition
“ON” and the engine “OFF” and note the
parameters.
2. Operate the vehicle within the Freeze Frame
conditions as noted.
Does P0201 reset?
—Go to Step 5
Go to
Diagnostic
Aids
51. Engine “OFF.”
2. Disconnect the injector connector.
3. Install an injector test light 5-8840-2636-0 on the
injector test connector.
4. Crank the engine and note the light.
Does the injector test light blink?
—
Go to Fuel
Injector Coil
Te s t
Procedure
Go to Step 6
6Note whether the injector test light for cylinder 1 was
“OFF” or “ON” steady in step 5.
Was the test light “ON” steady while cranking the
engine?
—Go to Step 7Go to Step 9

6E–172
ENGINE DRIVEABILITY AND EMISSIONS
DTC P0201 – Injector 1 Control Circuit
StepNo Ye s Va l u e ( s ) Action
71. Disconnect the PCM connector for the affected
injectors.
2. With a test light connected to B+, probe the affected
injector driver circuit.
Does the test light illuminate?
—Go to Step 8Go to Step 15
8Repair short to ground in the injector driver circuit.
Is the action complete?
—
Go to OBD
System
Check
—
91. Disconnect the injector test connector.
2. At the injector side of the harness, connect an
ohmmeter between the positive wire (red with blue
tracer) and the wire for cylinder 1 (green with white
tracer).
Does the ohmmeter indicate continuity?
—Go to Step 11Go to Step 10
10Repair the open injector harness wire or open injector.
Is the action complete?
—Verify repair—
11At the PCM side of the injector test connector, check
the green/white wire for a short to voltage.
Was there a short to voltage?
—Go to Step 12Go to Step 13
12Repair the short to voltage.
Is the action complete?
—Verify repair—
13Check for an open circuit between the injector test
connector and the PCM.
Was there an open circuit?
—Go to Step 14Go to Step 15
14Repair the open circuit.
Is the action complete?
—Verify repair—
15Replace the PCM.
IMPORTANT:The replacement PCM must be
programmed. Refer to
UBS 98model year Immobilizer
Workshop Manual.
Is the action complete?—Verify repair—

6E–173 ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0202 Injector 2 Control Circuit
D06RW034
Circuit Description
The powertrain control module (PCM) has six individual
injector driver circuits. Each controls an injector. When a
driver circuit is grounded by the PCM, the injector is
activated. The PCM monitors the current in each driver
circuit. The voltage on each driver is monitored to detect
a fault. If the voltage is not what the PCM expects to
m o n i t o r o n t h e c i r c u i t , a D T C i s s e t . T h i s D T C i s a l s o s e t i f
an injector driver is shorted to voltage or if there is an open
circuit.
Conditions for Setting the DTC
The battery voltage is more than 9 volts.
The engine is turning, determined by 58X crankshaft
position input signal.
The injector voltage does not equal the ignition voltage
when the injector is commanded “OFF” or the injector
voltage does not equal 0 volts when the injector is
commanded “ON.”
The above conditions are met for 15 seconds.
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 P0202 can be cleared by using the Tech 2 “Clear
Info” function or by disconnecting the PCM battery
feed.
Diagnostic Aids
An injector driver circuit that is open or shorted to voltage
will cause a DTC P0202 to set. It will also cause a misfire
due to an inoperative injector. A misfire DTC will also be
set indicating which cylinder is inoperative.
Long term and short term fuel trims that are excessively
high or low are a good indication that an injector is faulty.
Use Fuel Injector Coil Test Procedure to check for faulty
injectors.
Test Description
The number(s) below refer to the step number(s) on the
Diagnostic Chart.
3. This step determines if DTC P0202 is the result of a
hard failure or an intermittent condition.
5. A special injector test connector is provided so that
the injectors can be electrically tested without
removal of the manifold. On the Trooper, the
special 7-way gray connector is located at the front
of the charcoal canister. The test connector can be
identified by the blue connector lock which is
tethered to the wiring harness. If the light for
cylinder 2 is “ON” steady before cranking the engine
as well as while cranking the engine, then the
injector driver circuit is shorted to ground.

6E–174
ENGINE DRIVEABILITY AND EMISSIONS
If the test light blinks while cranking, the PCM and
the wiring to the injectors are OK. The Fuel Injector
Coil Test Procedure will check if the injectors are
faulty.
R321055
7. Because the test light was “ON” steady, voltage to
the injector is OK, but the driver circuit is grounded
at all times. This step determines if the circuit is
shorted to ground or the PCM is faulty.
9.The reading should be about 12-14
.
10.Locating the open in the harness or in the injector
will require removal of the manifold to provide
access.
DTC P0202 – Injector 2 Control Circuit
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
2Will the engine start?
—Go to Step 3
Go to Engine
Cranks But
Will Not Run
chart
31. Install the Tech 2. Clear the DTC.
2. Idle the engine for one minute.
Does DTC P0202 reset?
—Go to Step 5Go to Step 4
41. Review the Freeze Frame data with the ignition
“ON” and the engine “OFF” and note the
parameters.
2. Operate the vehicle within the Freeze Frame
conditions as noted.
Does P0202 reset?
—Go to Step 5
Go to
Diagnostic
Aids
51. Engine “OFF.”
2. Disconnect the injector test connector.
3. Install an injector test light 5-8840-2636-0 on
injector connector.
4. Crank the engine and note the light.
Does the cylinder 2 test light blink?
—
Go to Fuel
Injector Coil
Te s t
Procedure
Go to Step 6
6Note whether the injector test light for cylinder 2 was
“OFF” or “ON” steady in step 5.
Was the test light “ON” steady while cranking the
engine?
—Go to Step 7Go to Step 9

6E–175 ENGINE DRIVEABILITY AND EMISSIONS
DTC P0202 – Injector 2 Control Circuit
StepNo Ye s Va l u e ( s ) Action
71. Disconnect the PCM connector for the affected
injectors.
2. With a test light connected to B+, probe the affected
injector driver circuit.
Does the test light illuminate?
—Go to Step 8Go to Step 15
8Repair short to ground in the injector driver circuit.
Is the action complete?
—
Go to OBD
System
Check
—
91. Disconnect the injector test connector.
2. At the injector side of the harness, connect an
ohmmeter between the positive wire (red with blue
tracer) and the wire for cylinder 2 (green with orange
tracer).
Does the ohmmeter indicate continuity?
—Go to Step 11Go to Step 10
10Repair the open injector harness wire or open injector.
Is the action complete?
—Verify repair—
11At the PCM side of the injector test connector, check
the green/orange wire for a short to voltage.
Was there a short to voltage?
—Go to Step 12Go to Step 13
12Repair the short to voltage.
Is the action complete?
—Verify repair—
13Check for an open circuit between the injector test
connector and the PCM.
Was there an open circuit?
—Go to Step 14Go to Step 15
14Repair the open circuit.
Is the action complete?
—Verify repair—
15Replace the PCM.
IMPORTANT:The replacement PCM must be
programmed. Refer to
UBS 98model year Immobilizer
Workshop Manual.
Is the action complete?—Verify repair—