1998 OPEL FRONTERA coolant temperature

6E–39 4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS
Engine Control Module ECM
Diagnosis
To read and clear diagnostic trouble codes, use a Tech 2.
IMPORTANT:Use of a Tech 2 is recommended to clear
diagnostic trouble codes from the ECM memory.
Diagnostic trouble codes can also be cleared by turning
the ignition “OFF” and disconnecting the battery power
from the ECM for 30 seconds. Turning off the ignition and
disconnecting the battery power from the ECM will cause
all diagnostic information in the ECM memory to be
cleared. Therefore, all the diagnostic tests will have to be
re-run.
Since the ECM can have a failure which may affect only
one circuit, following the diagnostic procedures in this
section will determine which circuit has a problem and
where it is.
If a diagnostic chart indicates that the ECM connections
or the ECM is the cause of a problem, and the ECM is
replaced, but this does not correct the problem, one of the
following may be the reason:
There is a problem with the ECM terminal
connections. The terminals may have to be removed
from the connector in order to check them properly.
The problem is intermittent. This means that the
problem is not present at the time the system is being
checked. In this case, refer to the
Symptoms portion
of the manual and make a careful physical inspection
of all components and wiring associated with the
affected system.
There is a shorted solenoid, relay coil, or harness.
Solenoids and relays are turned “ON” and “OFF” by
the ECM using internal electronic switches called
drivers. A shorted solenoid, relay coil, or harness will
not damage the ECM but will cause the solenoid or
relay to be inoperative.
Multiple ECM Information Sensor
DTCS Set
Circuit Description
The Engine Control Module ECM monitors various
sensors to determine the engine operating conditions.
The ECM controls fuel delivery, spark advance,
transmission operation, and emission control device
operation based on the sensor inputs.
The ECM provides a sensor ground to all of the sensors.
The ECM applies 5 volts through a pull-up resistor, and
determines the status of the following sensors by
monitoring the voltage present between the 5-volt supply
and the resistor:
The fuel temperature (FT) sensor
The engine coolant temperature (ECT) sensor
The Intake air temperature (IAT) sensor
The ECM provides the following sensors with a 5-volt
reference and a sensor ground signal:
The Intake throttle position sensor
The manifold absolute pressure sensor
The rail pressure sensor
The accelerator position sensor
The oil temperature sensor
The camshaft position sensor
The crankshaft position sensor
The EGR pressure sensor
The ECM monitors the signals from these sensors in
order to determine their operating status.
Diagnostic Aids
IMPORTANT:Be sure to inspect ECM and engine
grounds for being secure and clean.
A short to voltage in one of the sensor input circuits may
cause one or more of the following DTCs to be set:
P0337
P0342
P1193
P1404
P1405
P1488
IMPORTANT:If a sensor input circuit has been shorted
to voltage, ensure that the sensor is not damaged. A
damaged sensor will continue to indicate a high or low
voltage after the affected circuit has been repaired. If the
sensor has been damaged, replace it.
An open in the sensor ground circuit between the ECM
and the splice will cause one or more of the following
DTCs to be set:
P0337
P0342
P0117
A short to ground in the 5-volt reference A or B circuit will
cause one or more of the following DTCs to be set:
P0112
P0117
P0182
P0197
An open in the 5-volt reference circuit A, between the
ECM and the splice will cause one or more of the following
DTCs to be set:
P0107
P0405
P1194
P0122
An open in the 5-volt reference circuit B, between the
ECM and the splice will cause one or more of the following
DTCs to be set:
P1485
Check for the following conditions:
Poor connection at ECM. 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:
ECT Sensor

6E–41 4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS
EGR (Exhaust Gas Recirculation)
Diagnosis
A diagnosis of the EGR system is covered by DTC
P1403.
EGR VSV circuit diagnosis is covered by DTC P1404.
EGR pressure sensor diagnosis is covered by DTC
P405 and/or P406.
EGR EVRV circuit diagnosis is covered by DTC
P1405. Refer to the DTC charts.
Tech 2 Data Definitions and Ranges
A/C CLUTCH–Tech 2 Displays ON or OFF–
Indicates whether the A/C has commanded the A/C
clutch ON.
MAP kPa — Tech 2 Range 10-105 kPa/0.00-5.00
Vo l t s —
The manifold absolute pressure reading is determined
from the MAP sensor signal monitored during key up and
wide open throttle (WOT) conditions. The manifold
absolute pressure is used to compensate for altitude
differences and is normally displayed around “61-104”
depending on altitude and manifold absolute pressure.
CMP ACT. COUNTER –Cam Position
DESIRED IDLE — Tech 2 Range 0-3187 RPM —
The idle speed that the ECM is commanding. The ECM
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 ECM. The ECM 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 ECM
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 ECM will interpret
the lower voltage as a warm engine.
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 ECM from the 57X
reference input. It should remain close to desired idle
under various engine loads with engine idling.Air Intake Valve meter POSITION — Tech 2 Range
0-100 % —
IAT (INTAKE AIR TEMPERATURE)— Tech 2 Range
–40
C to 151C (–40F to 304F) —
The ECM converts the resistance of the intake air
temperature sensor to degrees. Intake air temperature
(IAT) is used by the ECM to adjust fuel delivery and spark
timing according to incoming air density.
MAP — Tech 2 Range 10-105 kPa (0.00-4.97 Volts)—
The manifold absolute pressure (MAP) sensor measures
the change in the boost pressure.
MIL — Tech 2 Displays ON or OFF —
Indicates the ECM commanded state of the malfunction
indicator lamp.
AP — Tech 2 Range 0%-100% —
AP (Accelerator position) angle is computed by the ECM
from the AP sensor voltage. AP angle should display
“0%” at idle and “100%” at wide open throttle.
AP SENSOR — Tech 2 Range 0.00-5.00 Volts —
The voltage being monitored by the ECM on the AP
sensor signal circuit.
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.
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 ECM 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, accessaries off, brake not applied and air
conditioning off.

6E–43 4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS
Te c h 2
ParameterData ListUnits
DisplayedTy p i c a l D a t a
Values (IDLE)Typical Data
Va l u e s
(2500 RPM)Refer To
Exhaust VSV1EngineOn/OffOffOffDTC P0475
Exhaust VSV2EngineOn/OffOffOffDTC P1475
Decelevation
Fuel Cut OffEngineInactive/
Active——General Description
Glow Time
LampEngineOn/OffOffOffDTC P0381
Glow Time
RelayEngineOn/OffOffOffDTC P0380
Diagnostic
RequestEngineInactive
12V/
Active 0V——General Description
A/C ClutchEngineOn/OffOffOffGeneral Description
Desired IdleEngineRPM720—General Description
ECT (Engine
Coolant Temp)EngineC (F)80 9080 90General Description
ECT
Engine SpeedEngineRPM7202500DTC P0219
MAT (Intake Air
Te m p )EngineC (F)65 8065 80DTC P0112, P0113
MAP KPa
(Manifold
Absolute
Pressure)EngineKilopascals——General Description
DTC P0107, P0108
MILEngineOn/OffOffOffGeneral Description
AP (Accel
Position)EnginePercent08 14DTC P0121, P0122,
P0123
AP (Accel
Position)EngineVo l t s0.25 0.450.8 1.0DTC P0121, P0122,
P0123
Rail Oil
TemperatureEngineC (F)——DTC P0197, P0198
Desired Throttle
Motor PositionEngineSteps———
Learned Idle
Fuel QuantityEnginemm 3/st———

6E–49 4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS
Engine Cranks But Will Not Run
Circuit Description
In this type of injector system, the Engine Control Module
(ECM) triggers the correct driver inside the injector, which
then triggers the correct injector based on the 57X signal
received from the crankshaft position sensor (CKP).
During crank, the ECM monitors the CKP 57X signal. The
CKP signal is used to determine which cylinder will fire
first. After the CKP 57X signal has been processed by the
ECM, it will command all four injectors to allow a priming
shot of fuel for all the cylinders. After the priming, the
injectors are left “OFF” during the next four 57X reference
pulses from the CKP. This allows each cylinder a chance
to use the fuel from the priming shot. During this waiting
period, a camshaft position (CMP) signal pulse will have
been received by the ECM. The CMP signal allows the
ECM to operate the injectors sequentially based on
camshaft position. If the camshaft position signal is not
present at start-up, the ECM will begin sequential fuel
delivery with a 1-in-4 chance that fuel delivery is correct.
The engine will run without a CMP signal, but will set a
DTC code.
Diagnostic Aids
An intermittent problem may be caused by a poor
connection, rubbed-through wire insulation or a wirebroken inside the insulation. Check for the following
items:
Poor connection or damaged harness – Inspect the
ECM harness and connectors for improper mating,
broken locks, improperly formed or damaged
terminals, poor terminal-to-wore connection, and
damaged harness.
Faulty engine coolant temperature sensor – Using a
Tech 2, compare engine coolant temperature with
manifold air temperature on a completely cool engine.
Test Description
Number(s) below refer to the step number(s) on the
Diagnostic Chart.
4. An obvious cause of low fuel pressure would be an
empty fuel tank.
5. The engine will easily start and run if a few injectors
are disabled. It is not necessary to test all injectors
at this time since this step is only a test to verify that
all of the injectors have not been disabled by fuel
contamination.
8.If there is an open or shorted driver circuit, DTCs
0201-0204 should be set.
Engine Cranks But Will Not Run
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
2Check the 15 A injector fuse, the 15 A engine device
fuse, and the 15A ECM fuse.
Was a fuse blown?
—Go to Step 3Go to Step 4
3Check for a short to ground and replace the fuse.
Is the action complete?
—Verify repair—
4Is fuel tank empty?
—
Fill the fuel
tank
Go to Step 5
5Is the right fuel using?
—Go to Step 6
Replace the
fuel
6Is the right engine oil using?
—Go to Step 7
Replace the
engine oil
7Using the Tech–2.
Is DTC P0192 or P0193 set? (Check rail pressure
system)
—
Go to DTC
P0192 or
DTC P0193
Go to Step 8
8Using the Tech–2.
Is DTC P0201 – P0204 set? (Check inject circuit fault)
—
Go to DTC
P0201 –
P0204
Go to Step 9
9Using the Tech–2.
Is DTC P1657 set? (Check ECM Main relay)
—
Go to DTC
P1657
Go to Step 10

6E–65 4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0117 (Flash DTC 14)
ECT Sensor Low Voltage
060RW129
Circuit Description
The engine coolant temperature (ECT) sensor is a
thermistor mounted on a coolant crossover pipe at the
rear of the engine. The Engine Control Module ECM
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
ECM will measure a high signal voltage. As the engine
coolant warms, the sensor resistance becomes lower,
and the ECT signal voltage measured at the ECM drops.
Action Taken When the DTC Sets
The ECM 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 ECM battery
feed.
Diagnostic Aids
Check for the following conditions:
Poor connection at ECM – Inspect harness connectors
for backed-out terminals, improper mating, brokenlocks, 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.
If it is determined that the DTC occurs intermittently.
Test Description
Number(s) below refer to the step number(s) on the
Diagnostic Chart.
2. Verifies that the fault is present.
3. If DTC P0117 can be repeated only by duplicating
the Failure Records conditions, refer to the
“Temperature vs. Resistance Values” table. The
table may be used to test the ECT sensor at various
temperatures to evaluate the possibility of a
“shifted” sensor that may be shorted above or below
a certain temperature. If this is the case, replace
the ECT sensor. If the ECT sensor appears to be
OK, the fault is intermittent; refer to
Diagnostic Aids.

6E–66
4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS
Engine Coolant Temperature Sensor
CFOhms
Temperature vs. Resistance Values
(approximate)
25772796
15594450
DTC P0117 – ECT Sensor Low 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. Observe the “Eng Cool Temp” display on the Tech 2.
Is the “Eng Cool Temp” below the specified value?
139C
(282
F)Go 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 “ DTC” info for DTC P0117.
Does the Tech 2 indicate DTC P0117 failed this
ignition?
—Go to Step 4
Refer to
Diagnostic
Aids
41. Disconnect the ECT sensor electrical connector.
2. Observe the “Eng Cool Temp” display on the Tech 2.
Is the “Eng Cool Temp” at the specified value?
–39C
(–38
F)Go to Step 6Go to Step 5
51. Ignition “OFF.”
2. Disconnect the ECM and check the ECT signal
circuit for a short to ground or a short to the sensor
ground circuit.
3. If the ECT signal circuit is shorted. repair it as
necessary.
Was the ECT signal circuit shorted to ground?
—Verify repairGo to Step 7
6Replace the ECT sensor.
Is the action complete?
—Verify repair—
7Replace the ECM (Refer to the Data Programming in
Case of ECM change).
Is the action complete?
—Verify repair—

6E–67 4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0118 (Flash DTC 14)
ECT Sensor High Voltage
060RW129
Circuit Description
The engine coolant temperature (ECT) sensor is a
thermistor mounted in on a coolant crossover pipe at the
rear of the engine. The Engine Control Module ECM
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
ECM will measure a high signal voltage. As the engine
coolant warms, the sensor resistance becomes less, and
the ECT signal voltage measured at the ECM drops.
Action Taken When the DTC Sets
The ECM 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 ECM battery
feed.
Diagnostic Aids
Check for the following conditions:
Poor connection at ECM – 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.

6E–68
4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS
Test Description
Number(s) below refer to the step number(s) on the
Diagnostic Chart.
2. Verifies that the fault is present.
3. If DTC P0118 can be repeated only by duplicating
the Failure Records conditions, refer to the
“Temperature vs. Resistance Value” table. The
table may be used to test the ECT sensor at various
temperatures to evaluate the possibility of a
“shifted” sensor that may be shorted above or below
a certain temperature. If this is the case, replace
the ECT sensor. If the ECT sensor appears to be
OK, the fault is intermittent; refer to
Diagnostic Aids.
Engine Coolant Temperature Sensor
CFOhms
Temperature vs. Resistance Values
(approximate)
80176332
25772796
15594450
DTC P0118 – ECT Sensor 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. Observe the “Eng Cool Temp” display on the Tech 2.
Is the “Eng Cool Temp” below the specified value?
–39C
(–38
F)Go 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 the “ DTC” info for DTC
P0118.
Does the Tech 2 indicate DTC P0118 failed?
—
Refer to Te s t
Description
Refer to
Diagnostic
Aids
41. Disconnect the ECT sensor electrical connector.
2. Jumper the ECT signal circuit and the sensor
ground circuit together at the ECT sensor harness
connector.
3. Observe the “Eng Cool Temp” display on the Tech 2.
Is the “Eng Cool Temp” at the specified value?
140C
(284
F)Go to Step 6Go to Step 5
51. Jumper the ECT signal circuit at the ECT sensor
harness connector to chassis ground.
2. Observe the “Eng Cool Temp” display on the Tech 2.
Is the “Eng Cool Temp” at the specified value?
140C
(284
F)Go to Step 7Go to Step 8
6Check for poor connections at the ECT sensor and
replace terminals if necessary.
Did any terminals require replacement?
—Verify repairGo to Step 10
71. Ignition “OFF.”
2. Disconnect the ECM, and check the ECT sensor
ground circuit for an open.
3. If the ECT sensor ground circuit is open, repair it as
necessary.
Was the ECT sensor ground circuit open?
—Verify repairGo to Step 9