check engine OPEL FRONTERA 1998 Workshop Manual

6E–66
ENGINE DRIVEABILITY AND EMISSIONS
Poor connection at PCM. Inspect the harness
connectors for backed-out terminals, improper mating,
broken locks, improperly formed or damage terminals,
and a poor terminal-to-wire connection.
Damaged harness. Inspect the wiring harness for
damage. If the harness is not damaged, observe an
affected sensor’s displayed value on the Tech 2 with
the ignition “ON” and the engine “OFF” while you move
the connectors and the wiring harnesses related to the
following sensors:
IAT
ECT
TP
MAP
EGR
TFT
Multiple PCM Information Sensor DTCs Set
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. Turn the ignition “OFF,” disconnect the PCM.
2. Turn the ignition “ON,” check the 5 volt reference A
circuit for the following conditions:
A poor connection at the PCM.
An open between the PCM connector and the
splice.
A short to ground.
A short to voltage.
Is there an open or short?
—Go to Step 3Go to Step 4
3Repair the open or short.
Is the action complete?
—Verify repair—
4Check the sensor ground circuit for the following
conditions:
A poor connection at the PCM or the affected
sensors.
An open between the PCM connector and the
affected sensors.
Is there an open or a poor connection?
—Go to Step 5Go to Step 6
5Repair the open or the poor connection.
Is the action complete?
—Verify repair—
6Measure the voltage between the EGR pintle position
sensor signal circuit at the PCM harness connector and
ground.
Does the voltage measure near the specified value?
0 VGo to Step 7Go to Step 12
7Measure the voltage between the MAP sensor signal
circuit at the PCM harness connector and ground.
Does the voltage measure near the specified value?
0 VGo to Step 8Go to Step 15
8Measure the voltage between the TP sensor signal
circuit at the PCM harness connector and ground.
Does the voltage measure near the specified value?
0 VGo to Step 9Go to Step 16
9Measure the voltage between the IAT sensor signal
circuit at the PCM harness connector and ground.
Does the voltage measure near the specified value?
0 VGo to Step 10Go to Step 17
10Measure the voltage between the ECT sensor signal
circuit at the PCM harness connector and ground.
Does the voltage measure near the specified value?
0 VGo to Step 11Go to Step 18

6E–67 ENGINE DRIVEABILITY AND EMISSIONS
Multiple PCM Information Sensor DTCs Set
StepNo Ye s Va l u e ( s ) Action
111. Disconnect the EGR valve.
2. Measure the voltage between the EGR pintle
position sensor signal circuit at the PCM harness
connector and ground.
Does the voltage measure near the specified value?
0 VGo to Step 13Go to Step 18
12Measure the voltage between the TFT sensor signal
circuit at the PCM harness connector and ground.
Does the voltage measure near the specified value?
0 VGo to Step 20Go to Step 19
13Replace the EGR valve.
Is the action complete?
—Verify repair—
14Locate and repair the short to voltage in the MAP
sensor signal circuit.
Is the action complete?
—Verify repair—
15Locate and repair the short to voltage in the TP sensor
signal circuit.
Is the action complete?
—Verify repair—
16Locate and repair the short to voltage in the IAT sensor
signal circuit.
Is the action complete?
—Verify repair—
17Locate and repair the short to voltage in the ECT
sensor signal circuit.
Is the action complete?
—Verify repair—
18Locate and repair the short to voltage in the EGR pintle
position sensor signal circuit.
Is the action complete?
—Verify repair—
19Locate and repair the short to voltage in the TFT sensor
signal circuit.
Is the action complete?
—Verify repair—
20Replace the PCM.
IMPORTANT:The replacement PCM must be
programmed. Refer to
UBS 98model year Immobilizer
Workshop Manual.
Is the action complete?—
Go to OBD
System
Check
—

6E–68
ENGINE DRIVEABILITY AND EMISSIONS
Exhaust Gas Recirculation (EGR)
Diagnosis (For except EXPORT and
SOUTH AFRICA)
Pintle position error diagnosis is covered by DTC P0402,
P0404, P1404, P0405, P0406. If EGR diagnostic trouble
codes P0402, P0404, P1404, P0405, P0406 are
encountered, refer to the DTC charts.
Engine Tech 2 Data Definitions and
Ranges
A/C CLUTCH – Tech 2 Displays ON or OFF –
Indicates whether the PCM has commanded the A/C
clutch ON. Used in A/C system diagnostic.
A/C REQUEST — Tech 2 Displays YES or NO —
Indicates the state of the A/C request input circuit from the
HVAC controls. The PCM uses the A/C request signal to
determine whether A/C compressor operation is being
requested.
AIR/FUEL RATIO — Tech 2 Range 0.0-25.5 —
Air/fuel ratio indicates the PCM commanded value. In
closed loop, the air/fuel ratio should normally be
displayed around “14.2-14.7.” A lower air/fuel ratio
indicates a richer commanded mixture, which may be
seen during power enrichment or TWC protection modes.
A higher air/fuel ratio indicates a leaner commanded
mixture. This can be seen during deceleration fuel mode.
BAROMETRIC PRESSURE — Tech 2 Range 10-105
kPa/0.00-5.00 Volts —
The barometric pressure reading is determined from the
MAP sensor signal monitored during key up and wide
open throttle (WOT) conditions. The barometric pressure
is used to compensate for altitude differences and is
normally displayed around “61-104” depending on
altitude and barometric pressure.
CHECK TRANS LAMP — AUTO TRANSMISSION —
Indicates the need to check for a DTC with the Tech 2
when the lamp is flashing 0.2 seconds ON and 0.2
seconds OFF.
CMP ACT. COUNTER – Cam Position Activity
DECEL FUEL MODE — Tech 2 Display ACTIVE or
INACTIVE —
“ACTIVE” displayed indicates that the PCM has detected
conditions appropriate to operate in deceleration fuel
mode. The PCM will command the deceleration fuel
mode when it detects a closed throttle position while the
vehicle is traveling over 20 mph. While in the deceleration
fuel delivered by entering open loop and decreasing the
injector pulse width.
DESIRED EGR POS. — Tech 2 Range 0%-100% —
Represents the EGR pintle position that the PCM is
commanding.
DESIRED IDLE — Tech 2 Range 0-3187 RPM —
The idle speed that the PCM is commanding. The PCM
will compensate for various engine loads based on engine
coolant temperature, to keep the engine at the desired
speed.ECT — (Engine Coolant Temperature) Tech 2
Range –40
C to 151C (–40F to 304F) —
The engine coolant temperature (ECT) is mounted in the
coolant stream and sends engine temperature
information to the PCM. The PCM applies 5 volts to the
ECT sensor circuit. The sensor is a thermistor which
changes internal resistance as temperature changes.
When the sensor is cold (high resistance), the PCM
monitors a high signal voltage and interprets that as a cold
engine. As the sensor warms (decreasing resistance),
the voltage signal will decrease and the PCM will interpret
the lower voltage as a warm engine.
EGR DUTY CYCLE — Tech 2 Range 0%-100% —
Represents the EGR valve driver PWM signal from the
PCM. A duty cycle of 0% indicates that no EGR flow is
being commanded; a 100% duty cycle indicates
maximum EGR flow commanded.
EGR FEEDBACK — Tech 2 Range 0.00-5.00 Volts —
Indicates the EGR pintle position sensor signal voltage
being monitored by the PCM. A low voltage indicates a
fully extended pintle (closed valve); a voltage near 5 volts
indicates a retracted pintle (open valve).
ENGINE LOAD — Tech 2 Range 0%-100% —
Engine load is calculated by the PCM from engine speed
and MAF sensor readings. Engine load should increase
with an increase in RPM or air flow.
ENGINE RUN TIME — Tech 2 Range
00:00:00-99:99:99 Hrs:Min:Sec —
Indicates the time elapsed since the engine was started.
If the engine is stopped, engine run time will be reset to
00:00:00.
ENGINE SPEED — Range 0-9999 RPM —
Engine speed is computed by the PCM from the 58X
reference input. It should remain close to desired idle
under various engine loads with engine idling.
FUEL PUMP — Tech 2 Displays ON or OFF —
Indicates the PCM commanded state of the fuel pump
relay driver circuit.
FUEL TRIM CELL — Tech 2 Range 0-21 —
The fuel trim cell is dependent upon engine speed and
MAF sensor readings. A plot of RPM vs. MAF is divided
into 22 cells. Fuel trim cell indicates which cell is currently
active.
FUEL TRIM LEARN — Tech 2 Displays NO or YES
—
When conditions are appropriate for enabling long term
fuel trim corrections, fuel trim learn will display “YES.”
This indicates that the long term fuel trim is responding to
the short term fuel trim. If the fuel trim learn displays
“NO,” then long term fuel trim will not respond to changes
in short term fuel trim.
HO2S BANK 1, SEN. 1 — Tech 2 Range 0-1132 mV
—
Represents the fuel control exhaust oxygen sensor
output voltage. Should fluctuate constantly within a range
between 10 mV (lean exhaust) and 1000 mV (rich
exhaust) while operating in closed loop.

6E–70
ENGINE DRIVEABILITY AND EMISSIONS
SPARK — Tech 2 Range –64 to 64 —
Displays the amount of spark advance being commanded
by the PCM on the IC circuit.
START-UP ECT — Tech 2 Range –40
C to 151C
(–40
F to 304F) —
Indicates the engine coolant temperature at the time that
the vehicle was started. Used by the HO2S diagnostic to
determine if the last start-up was a cold start.
START-UP IAT — Tech 2 Range –40
C to 151C
(–40
F to 304F) —
Indicates the intake air temperature at the time that the
vehicle was started. Used by the HO2S diagnostic to
determine if the last start-up was a cold start.
TP — Tech 2 Range 0%-100% —
TP (throttle position) angle is computed by the PCM from
the TP sensor voltage. TP angle should display “0%” at
idle and “100%” at wide open throttle.
TP SENSOR — Tech 2 Range 0.00-5.00 Volts —
The voltage being monitored by the PCM on the TP
sensor signal circuit.
CATALYST PROTECTION MODE — Tech 2 Displays
YES or NO —
“YES” displayed indicates that the PCM has detected
conditions appropriate to operate in TWC protection
mode. The PCM will decrease the air/fuel ratio to a value
that depends on mass air flow (higher mass air flow =
lower air/fuel ratio).
UPSHIFT LAMP (MANUAL TRANSMISSION)
VEHICLE SPEED — Tech 2 Range 0-255 km/h
(0-155 mph) —
The vehicle speed sensor signal is converted into km/h
and mph for display.
WEAK CYLINDER — Tech 2 Displays Cylinder
Number —
This indicates that the PCM has detected crankshaft
speed variations that indicate 2% or more cylinder firing
events are misfires.
Typical Scan Data Values
Use the Typical Scan Data Values Table only after the
On-Board Diagnostic System Check has been
completed, no DTC(s) were noted, and you have
determined that the on-board diagnostics are functioning
properly. Tech 2 values from a properly-running engine
may be used for comparison with the engine you are
diagnosing. The typical scan data values represent
values that would be seen on a normally-running engine.
NOTE: A Tech 2 that displays faulty data should not be
used, and the problem should be reported to the Tech 2
manufacturer. Use of a faulty Tech 2 can result in
misdiagnosis and unnecessary replacement of parts.
Only the parameters listed below are referred to in this
service manual for use in diagnosis. For further
information on using the Tech 2 to diagnose the PCM and
related sensors, refer to the applicable reference section
listed below. If all values are within the typical range
described below, refer to the
Symptoms section for
diagnosis.
Test Conditions
Engine running, lower radiator hose hot, transmission in
park or neutral, closed loop, accessaries off, brake not
applied and air conditioning off.

6E–72
ENGINE DRIVEABILITY AND EMISSIONS
Te c h 2
ParameterRefer To Typical Data
Va l u e s
(2500 RPM) Typical Data
Values (IDLE) Units
Displayed Data List
HO2S Bank 2
Sen.1 (millivolts)O2 Sensor
DataMillivolts50-950 changing
quickly50-950 changing
quicklyGeneral Description and
Operation, Fuel Control
HO2S
HO2S Bank 1
Sen.1
(ready/not
ready)O2 Sensor
DataReady
Ye s / N oReady
Ye sReady
Ye sGeneral Description and
Operation, Fuel Control
HO2S; DTC: P0135
HO2S Bank 2
Sen.1
(ready/not
ready)O2 Sensor
DataReady
Ye s / N oReady
Ye sReady
Ye sGeneral Description and
Operation, Fuel Control
HO2S
HO2S Warm-Up
Time Bank 1
Sen.1O2 Sensor
DataSeconds25-4525-45General Description and
Operation, Fuel Control
HO2S
HO2S Warm-Up
Time Bank 2
Sen.1O2 Sensor
DataSeconds25-4525-45General Description and
Operation, Fuel Control
HO2S
IAT (Intake Air
Te m p )EngineDegrees C,
Degrees F0-100C,
depends on
underhood0-80C, depends
on underhoodGeneral Description and
Operation, Intake Air
Temperature (IAT) Sensor
Ignition VoltageEngineVo l t s12.8-14.112.8-14.1General Description and
Operation, Electronic
Ignition System
Inj. Pulse Bank
1EngineMillisecond
s2.0-4.02.5-4.0General Description, Fuel
Metering, Fuel Injector
Inj. Pulse Bank
2EngineMillisecond
s2.0-4.02.5-4.0General Description, Fuel
Metering, Fuel Injector
KS Noise
Channel (Knock
Sensor)EngineVo l t s0.10-0.400.50-1.75General Description and
Operation, Knock Sensor
Purpose and Operation;
DTCs: P0352, P0327
Loop StatusEngineOpen/Clos
edClosedClosedGeneral Description and
Operation, Fuel Metering
System; DTCs:
P0125-P0155
MAF (Mass Air
Flow)EngineGrams per
second2.85-6.659.5-16.5General Description and
Operation, MAF; DTCs:
P101, P0102, P0103
MAP kPa
(Manifold
Absolute
Pressure)EngineKilopascals
——
General Description and
Operation, Manifold
Absolute Pressure (MAP)
Sensor; DTCs: P0106,
P0107, P0108
MILEngineOn/OffOffOffOn-Board Diagnostic
System Check
Power
EnrichmentEngineInactive/Ac
tiveInactiveInactiveGeneral Description and
Operation, Acceleration
Mode
Spark
(Advance)EngineDegrees
Before Top
Dead
Center15-2234-44General Description and
Operation, Electronic
Ignition System

6E–74
ENGINE DRIVEABILITY AND EMISSIONS
No Malfunction Indicator Lamp (MIL)
D06RW00006
Circuit Description
The “Check Engine” lamp (MIL) should always be
illuminated and steady with the ignition “ON” and the
engine stopped. Ignition feed voltage is supplied to the
MIL bulb through the meter fuse. The powertrain control
module (PCM) turns the MIL “ON” by grounding the MIL
driver circuit.
Diagnostic Aids
An intermittent MIL may be cased by a poor connection,
rubbed-through wire insulation, or a wire broken inside
the insulation. Check for the following items:
Inspect the PCM harness and connections for
improper mating, broken locks, improperly formed or
damaged terminals, poor terminal-to-wire connection,
and damaged harness.
If the engine runs OK, check for a faulty light bulb, an
open in the MIL driver circuit, or an open in the
instrument cluster ignition feed.
If the engine cranks but will not run, check for an open
PCM ignition or battery feed, or a poor PCM to engine
ground.
Test Description
Number(s) below refer to the step number(s) on the
Diagnostic Chart.
2. A “No MIL” condition accompanied by a no-start
condition suggests a faulty PCM ignition feed or
battery feed circuit.
9. Using a test light connected to B+, probe each of the
PCM ground terminals to ensure that a good ground
is present. Refer to
PCM Terminal End View for
terminal locations of the PCM ground circuits.
12.In this step, temporarily substitute a known good
relay for the PCM relay. The horn relay is nearby,
and it can be verified as “good” simply by honking
the horn. Replace the horn relay after completing
this step.

6E–75 ENGINE DRIVEABILITY AND EMISSIONS
17.This vehicle is equipped with a PCM which utilizes
an electrically erasable programmable read only
memory (EEPROM). When the PCM is replaced,
the new PCM must be programmed. Refer to
UBS
98 model year Immobilizer Workshop Manual.
No Malfunction Indicator Lamp (MIL)
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
2Attempt to start the engine.
Does the engine start?
—Go to Step 3Go to Step 6
3Check the meter fuse for the instrument cluster ignition
feed circuit.
Is the fuse OK?
—Go to Step 4Go to Step 16
4Ignition “ON,” probe the ignition feed circuit at the
cluster connector with a test light to ground.
Is the test light “ON?”
—Go to Step 5Go to Step 13
51. Ignition “OFF.”
2. Disconnect the PCM.
3. Jumper the MIL driver circuit at the PCM connector
to ground.
4. Ignition “ON.”
Is the MIL “ON?”
—Go to Step 10Go to Step 11
6Check the PCM ignition feed and battery feed fuses (15
A engine fuse and 15 A PCM fuse).
Are both fuses OK?
—Go to Step 7Go to Step 15
71. Ignition “OFF.”
2. Disconnect the PCM.
3. Ignition “ON.”
4. Probe the ignition feed circuit at the PCM harness
connector with a test light to ground.
Is the test light “ON?”
—Go to Step 8Go to Step 12
8Probe the battery feed circuit at the PCM harness
connector with a test light to ground.
Is the test light “ON?”
—Go to Step 9Go to Step 14
9Check for a faulty PCM ground connection.
Was a problem found?
—Verify repairGo to Step 10
10Check for damaged terminals at the PCM.
Was a problem found?
—Verify repairGo to Step 17
11Check for an open MIL driver circuit between the PCM
and the MIL.
Was a problem found?
—Verify repairGo to Step 18
12Substitute a known “good” relay for the PCM main
relay.
Was the malfunction fixed?
—Verify repairGo to Step 13
13Repair the open in the ignition feed circuit.
Is the action complete?
—Verify repair—

6E–76
ENGINE DRIVEABILITY AND EMISSIONS
No Malfunction Indicator Lamp (MIL)
StepNo Ye s Va l u e ( s ) Action
14Locate and repair the open PCM battery feed circuit.
Is the action complete?
—Verify repair—
15Locate and repair the short to ground in the PCM
ignition feed circuit or PCM battery feed circuit.
Is the action complete?
—Verify repair—
16Locate and repair the short to ground in the ignition
feed circuit to the instrument cluster, and replace the
fuse.
Is the action complete?
—Verify repair—
17Replace the PCM.
IMPORTANT:The replacement PCM must be
programmed. Refer to
PCM in ON-Vehicle Service for
procedures.
Is the action complete?
—Verify repair—
18Check the MIL driver circuit for a poor connection at the
instrument panel connector.
Was a problem found?
—Verify repair
Go to
Instrument
Panel
in
Electrical
Diagnosis

6E–77 ENGINE DRIVEABILITY AND EMISSIONS
Malfunction Indicator Lamp (MIL) “ON” Steady
D06RW00007
Circuit description
The malfunction indicator lamp (MIL) should always be
illuminated and steady with ignition “ON” and the engine
stopped. Ignition feed voltage is supplied directly to the
MIL indicator. The powertrain control module (PCM)
turns the MIL “ON” by grounding the MIL driver circuit.
The MIL should not remain “ON” with the engine running
and no DTC(s) set. A steady MIL with the engine running
and no DTC(s) suggests a short to ground in the MIL
driver circuit.
Diagnostic Aids
An intermittent may be caused by a poor connection,
rubbed-through wire insulation, or a wire broken inside
the insulation. Check for the following items:
Poor connection or damaged harness – Inspect the
PCM harness and connectors for improper mating,
broken locks, improperly formed or damaged
terminals, poor terminal-to-wire connection, and
damaged harness.
Test Description
Number(s) below refer to the step number(s) on the
Diagnostic Chart.
2. If the MIL does not remain “ON” when the PCM is
disconnected, the MIL driver wiring is not faulty.
3. If the MIL driver circuit is OK, the instrument panel
cluster is faulty.
6. This vehicle is equipped with a PCM which utilizes
an electrically erasable programmable read only
memory (EEPROM). When the PCM is replaced,
the new PCM must be programmed. Refer to
UBS
98 model year Immobilizer Workshop Manual.

6E–78
ENGINE DRIVEABILITY AND EMISSIONS
Malfunction Indicator Lamp (MIL) “ON” Steady
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 “OFF,” disconnect PCM.
2. Ignition “ON,” observe the MIL (Service Engine
Soon lamp).
Is the MIL “ON?”
—Go to Step 3Go to Step 5
31. Ignition “OFF,” disconnect the instrument panel
cluster.
2. Check the MIL driver circuit between the PCM and
the instrument panel cluster for a short to ground.
3. If a problem is found, repair as necessary.
Was the MIL driver circuit shorted to ground?
—
Go to OBD
System
Check
Go to Step 4
4Replace the instrument panel cluster.
Is the action complete?
—
Go to OBD
System
Check
—
51. Ignition “OFF,” reconnect the PCM.
2. Using Tech 2, select “Output Miscellaneous Test”
and command the MIL “OFF.”
Did the MIL turn “OFF?”
—
Go to OBD
System
Check
Go to Step 6
6Replace the PCM.
IMPORTANT:The replacement PCM must be
programmed. Refer to
UBS 98model year Immobilizer
Workshop Manual.
Is the action complete?—
Go to OBD
System
Check
—