Electrical OPEL FRONTERA 1998 Workshop Manual

6E–24
4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS
Diagnosis
Strategy-Based Diagnostics
Strategy-Based Diagnostics
The strategy-based diagnostic is a uniform approach to
repair all Electrical/Electronic (E/E) systems. The
diagnostic flow can always be used to resolve an E/E
system problem and is a starting point when repairs are
necessary. The following steps will instruct the technician
how to proceed with a diagnosis:
1. Verify the customer complaint.
To verify the customer complaint, the technician
should know the normal operation of the system.
2. Perform preliminary checks.
Conduct a thorough visual inspection.
Review the service history.
Detect unusual sounds or odors.
Gather diagnostic trouble code information to
achieve an effective repair.
3. Check bulletins and other service information.
This includes videos, newsletters, etc.
4. Refer to service information (manual) system
check(s).
“System checks” contain information on a system
that may not be supported by one or more DTCs.
System checks verify proper operation of the
system. This will lead the technician in an
organized approach to diagnostics.
5. Refer to service diagnostics.
DTC Stored
Follow the designated DTC chart exactly to make an
effective repair.
No DTC
Select the symptom from the symptom tables. Follow the
diagnostic paths or suggestions to complete the repair.
You may refer to the applicable component/system check
in the system checks.
No Matching Symptom
1. Analyze the complaint.
2. Develop a plan for diagnostics.
3. Utilize the wiring diagrams and the theory of
operation.
Call technical assistance for similar cases where repair
history may be available. Combine technician knowledge
with efficient use of the available service information.
Intermittents
Conditions that are not always present are called
intermittents. To resolve intermittents, perform the
following steps:
1. Observe history DTCs, DTC modes, and freezeframe
data.2. Evaluate the symptoms and the conditions described
by the customer.
3. Use a check sheet or other method to identify the
circuit or electrical system component.
4. Follow the suggestions for intermittent diagnosis
found in the service documentation.
Most scan tools, such as the Tech 2 and the DVM, have
data-capturing capabilities that can assist in detecting
intermittents.
No Trouble Found
This condition exists when the vehicle is found to operate
normally. The condition described by the customer may
be normal. Verify the customer complaint against another
vehicle that is operating normally. The condition may be
intermittent. Verify the complaint under the conditions
described by the customer before releasing the vehicle.
1. Re-examine the complaint.
When the complaint cannot be successfully found or
isolated, a re-evaluation is necessary. The complaint
should be re-verified and could be intermittent as
defined in
Intermittents, or could be normal.
2. Repair and verify.
After isolating the cause, the repairs should be made.
Validate for proper operation and verify that the
symptom has been corrected. This may involve road
testing or other methods to verify that the complaint
has been resolved under the following conditions:
Conditions noted by the customer.
If a DTC was diagnosed, verify a repair by
duplicating conditions present when the DTC was
set as noted in the Failure Records or Freeze
Frame data.
Verifying Vehicle Repair
Verification of the vehicle repair will be more
comprehensive for vehicles with OBD system
diagnostics. Following a repair, the technician should
perform the following steps:
IMPORTANT:Follow the steps below when you verify
repairs on OBD systems. Failure to follow these steps
could result in unnecessary repairs.
1. Review and record the Failure Records and the
Freeze Frame data for the DTC which has been
diagnosed (Freeze Frame data will only be stored for
the MIL (“Check Engine” lamp) has been requested).
2. Clear the DTC(s).
3. Operate the vehicle within conditions noted in the
Failure Records and Freeze Frame data.
4. Monitor the DTC status information for the specific
DTC which has been diagnosed until the diagnostic
test associated with that DTC runs.

6E–46
4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS
No Malfunction Indicator Lamp (MIL)
StepNo Ye s Va l u e ( s ) Action
15Locate and repair the short to ground in the ECM
ignition feed circuit or ECM 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 ECM (Refer to the Data Programming in
Case of ECM change).
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–61 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 P0112 can be repeated only by duplicating
the Failure Records condition, refer to the
Temperature vs. Resistance Value table. The table
may be used to test the IAT sensor at various
temperatures to evaluate the possibility of a
“shifted” sensor that may be stored above or below
a certain temperature. If this is the case, replace
the IAT sensor. If the IAT sensor appears to be OK,
the fault is intermittent; refer to
Diagnostic Aids.
Intake Air Temperature Sensor
CFOhms
Temperature vs. Resistance Values
(approximate)
25772796
15594450
5417280
DTC P0112 – IAT 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. Using a Tech 2, monitor the intake air temperature
(IAT).
Is the intake air temperature greater than the specified
value?
148C
(283
F)Go to Step 4Go to Step 3
31. Ignition “ON,” engine “OFF.” Review and record
Tech 2 Failure Records data.
2. Operate the vehicle within Failure Records
conditions as noted.
3. Using a Tech 2, monitor the “ DTC” info for DTC
P0112.
Does the Tech 2 indicate DTC P0112 failed this
ignition?
—
Refer to Te s t
Description
Refer to
Diagnostic
Aids
41. Ignition “OFF.”
2. Disconnect the IAT sensor electrical connector.
3. Ignition “ON.”
4. Observe the manifold air temperature on the Tech 2.
Is the manifold air temperature below the specified
value?
–38C
(–36
F)Go to Step 6Go to Step 5
51. Ignition “OFF.”
2. Disconnect the ECM electrical connectors.
3. Check the IAT sensor signal circuit for a short to
ground.
Is the IAT sensor signal circuit shorted to ground?
—Verify repairGo to Step 7
6Replace the IAT 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–63 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 P0113 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 MAT sensor at various
temperatures to evaluate the possibility of a
“shifted” sensor that may be open above or below a
certain temperature. If this is the case, replace the
MAT sensor. If the MAT sensor appears to be OK,
the fault is intermittent; refer to
Diagnostic Aids.
Manifold Air Temperature Sensor
CFOhms
Temperature vs. Resistance Values
(approximate)
25772796
15594450
5417280
DTC P0113 –IAT 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
2Ignition “ON,” engine “OFF.” Observe the “Intake Air
Temp” display on the Tech 2.
Is the “Intake Air Temp” below the specified value?
–38C
(–36
F)Go to Step 4Go to Step 3
31. Ignition “ON,” engine “OFF.”
2. Review and record Tech 2 Failure Records data
parameters.
3. Operate the vehicle within Failure Records
conditions as noted.
4. Using a Tech 2, monitor “ DTC” info for DTC P0113.
Does the Tech 2 indicate DTC P0113 failed?
—
Refer to Te s t
Description
Refer to
Diagnostic
Aids
41. Ignition “OFF.”
2. Disconnect the IAT sensor electrical connector.
3. Jumper the IAT signal circuit and the sensor ground
circuit together at the IAT sensor harness
connector.
4. Ignition “ON.”
5. Observe the “Intake Air Temp” display on the Tech
2.
Is the “Intake Air Temp” at the specified value?
140C
(284
F)Go to Step 6Go to Step 5
51. Jumper the IAT signal circuit at the IAT sensor
harness connector to chassis ground.
2. Observe the “Intake Air Temp” display on the Tech
2.
Is the “Intake Air Temp” at the specified value?
140C
(284
F)Go to Step 7Go to Step 8
6Check for poor connections at the IAT 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 IAT sensor
ground circuit for an open.
3. If the IAT sensor ground circuit is open, repair it as
necessary.
Was the IAT sensor ground circuit open?
—Verify repairGo to Step 9

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–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

6E–73 4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS
DTC P0122 –AP Sensor Low Voltage
StepNo Ye s Va l u e ( s ) Action
31. Ignition “ON,” engine “OFF.”
2. With the throttle closed, observe the “AP Sensor”
display on the Tech 2.
Is the “AP Sensor” below the specified value?
0.1 VGo to Step 5Go to Step 4
41. 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
P0122.
Does the Tech 2 indicate DTC P0122 failed?
—Go to Step 5
Refer to
Diagnostic
Aids
51. Ignition “OFF.”
2. Disconnect the AP sensor electrical connector.
3. Jumper the 5 volt reference “J2” circuit and the AP
signal together at the AP sensor harness connector.
4. Ignition “ON.”
Observe the “AP Sensor” display on the Tech 2.
Is the “AP Sensor” at the specified value?
5 VGo to Step 11Go to Step 6
61. Disconnect jumper.
2. Connect a test light between B+ and the AP sensor
signal circuit at the AP sensor harness connector.
Observe the “AP Sensor” display on the Tech 2.
Is the “AP Sensor” at the specified value?
5 VGo to Step 7Go to Step 9
71. Ignition “OFF.”
2. Disconnect the ECM and check the 5 volt reference
“A” circuit for an open or short to ground.
3. If the 5 volt reference “J2” circuit is open or shorted
to ground, repair it as necessary.
Was the 5 volt reference “J2” circuit open or shorted to
ground?
—Verify repairGo to Step 8
8Check the 5 volt reference “J2” circuit for a poor
connection at the ECM and replace the terminal if
necessary.
Did the terminal require replacement?
—Verify repairGo to Step 13
91. Ignition “OFF.”
2. Disconnect the ECM, and check the AP signal
circuit for an open, short to ground, or short to the
sensor ground circuit.
3. If the AP sensor signal circuit is open or shorted to
ground, repair it as necessary.
Was the AP signal circuit open or shorted to ground?
—Verify repairGo to Step 10
10Check the AP sensor signal circuit for a poor
connection at the ECM and replace the terminal if
necessary.
Did the terminal require replacement?
—Verify repairGo to Step 13
11Check the AP sensor signal circuit for a poor
connection at the AP sensor and replace the terminal if
necessary.
Did the terminal require replacement?
—Verify repairGo to Step 12

6E–76
4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS
DTC P0123 – AP 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
2Check the AP sensor signal circuit.
Was the AP sensor signal circuit open or darmage?
—
Replace the
APS circuit
Go to Step 3
31. Ignition “ON,” engine “OFF.”
2. With the throttle closed, observe the “AP Sensor”
display on the Tech 2.
Is the “AP Sensor” above the specified value?
4.5 VGo to Step 5Go to Step 4
41. 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 P0123.
Does the Tech 2 indicate DTC P0123 failed.
—Go to Step 5
Refer to
Diagnostic
Aids
51. Disconnect the AP sensor electrical connector.
2. Observe the “AP Sensor” display on the Tech 2.
Is the “AP Sensor” near the specified value?
0 VGo to Step 6Go to Step 7
6Probe the sensor ground circuit at the AP sensor
harness connector with a test light connected to B+.
Is the test light “ON?”
—Go to Step 8Go to Step 11
71. Ignition “OFF,” disconnect the ECM.
2. Ignition “ON,” engine “OFF.”
3. Check for a short to voltage on the AP sensor signal
circuit.
4. If the AP sensor signal circuit is shorted, repair it as
necessary.
Was the AP sensor signal circuit shorted?
—Verify repairGo to Step 13
81. Ignition “ON.”
2. Monitor the “AP Sensor” Tech 2 display while
disconnecting each of the components that share
the 5 volt reference “J2” circuit (one at a time).
3. If the “AP Sensor” Tech 2 display changes, replace
the component that caused the display to change
when disconnected.
Does disconnecting any of these components cause
the “AP Sensor” display to change?
—Verify repairGo to Step 9
91. Ignition “OFF,” disconnect the ECM.
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 “J2” circuit is shorted, repair it
as necessary.
Was the 5 volt reference “J2” circuit shorted?
—Verify repairGo to Step 10
10Check for poor electrical connections at the AP sensor
and replace terminals if necessary.
Did any terminals require replacement?
—Verify repairGo to Step 12

6E–79 4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS
DTC P0182 – FT 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 “Fuel Temp” display on the Tech 2.
Is the “Fuel 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 P0182.
Does the Tech 2 indicate DTC P0182 failed this
ignition?
—Go to Step 4
Refer to
Diagnostic
Aids
41. Disconnect the FT sensor electrical connector.
2. Observe the “Fuel Temp” display on the Tech 2.
Is the “Fuel 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 FT signal circuit
for a short to ground or a short to the sensor ground
circuit.
3. If the FT signal circuit is shorted. repair it as
necessary.
Was the FT signal circuit shorted to ground?
—Verify repairGo to Step 7
6Replace the FT 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–81 4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS
DTC P0183 – FT 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 “Fuel Temp” display on the Tech 2.
Is the “Fuel 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
P0183.
Does the Tech 2 indicate DTC P0183 failed?
—
Refer to Te s t
Description
Refer to
Diagnostic
Aids
41. Disconnect the FT sensor electrical connector.
2. Jumper the FT signal circuit and the sensor ground
circuit together at the FT sensor harness connector.
3. Observe the “Fuel Temp” display on the Tech 2.
Is the “Fuel Temp” at the specified value?
140C
(284
F)Go to Step 6Go to Step 5
51. Jumper the FT signal circuit at the FT sensor
harness connector to chassis ground.
2. Observe the “Fuel Temp” display on the Tech 2.
Is the “Fuel Temp” at the specified value?
140C
(284
F)Go to Step 7Go to Step 8
6Check for poor connections at the FT 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 FT sensor
ground circuit for an open.
3. If the FT sensor ground circuit is open, repair it as
necessary.
Was the FT sensor ground circuit open?
—Verify repairGo to Step 9
81. Ignition “OFF.”
2. Disconnect the ECM, and check the FT signal
circuit for an open.
3. If the FT sensor signal circuit is open, repair it as
necessary.
Was the FT signal circuit open?
—Verify repairGo to Step 9
9Check for a poor sensor ground or FT signal circuit
terminal connection at the ECM and replace
terminal(s) if necessary.
Did any of the terminals need to be replaced?
—Verify repairGo to Step 11
10Replace the FT sensor.
Is the action complete?
—Verify repair—
11Replace the ECM (Refer to the Data Programming in
Case of ECM change).
Is the action complete?
—Verify repair—