width OPEL FRONTERA 1998 Repair Manual
Page 4802 of 6000
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 
Page 4805 of 6000
6E–148
ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0151 HO2S Circuit Low Voltage Bank 2 
Sensor 1
060RW190
Circuit Description
The  powertrain  control  module  (PCM)  supplies  a  bias
voltage  of  about  450 mV  between  the  heated  oxygen
sensor (HO2S) signal high and signal low circuits.  When
measured 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 2 HO2S 1 voltage
remains excessively low for an extended period of time,
DTC P0151 will be set.
Conditions for Setting the DTC
No related DTCs.
The engine is operating in “closed loop.”
Engine coolant temperature is above 60C (140F).
“Closed  loop”  commanded  air/fuel  ratio  is  between
14.5 and 14.8.
Throttle angle is between 3% and 19%.
Bank 2 HO2S 1 signal voltage remains below 22 mV
during normal “closed loop” operation for a total of 77
seconds over a 90-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.
“Open loop” fuel control will be in effect.
Conditions for Clearing the MIL/DTC
DTC P0151 can be cleared by using Tech 2 “Clear Info”
function or by disconnecting the PCM battery feed.
Diagnostic Aids
Check for the following conditions:
Heated oxygen sensor wiring – The sensor pigtail may
be mispositioned and contacting the exhaust system.
Poor PCM to engine block grounds.
Fuel pressure – The system will go lean if pressure is
too  low.    The  PCM  can  compensate  for  some
decrease.  However, if fuel pressure is too low, a DTC
P0151 may be set.  Refer to 
Fuel System Diagnosis.
Lean injector(s) – Perform “Injector Balance Test.”
Vacuum leaks – Check for disconnected or damaged
vacuum  hoses  and  for  vacuum  leaks  at  the  intake
manifold, throttle body, EGR system, and PCV system.
Exhaust leaks – An exhaust leak may cause outside air
to  be  pulled  into  the  exhaust  gas  stream  past  the
HO2S, causing the system to appear lean.  Check for 
Page 4808 of 6000
6E–151 ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0152 HO2S Circuit HIGH Voltage Bank 2 
Sensor 1
060RW190
Circuit Description
The  powertrain  control  module  (PCM)  supplies  a  bias
voltage  of  about  450 mV  between  the  heated  oxygen
sensor (HO2S) signal high and signal low circuits.  When
measured 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 the injector
pulse width as necessary.  If the Bank 2 HO2S 1 voltage
remains excessively high for an extended period of time,
DTC P0152 will be set.
Conditions for Setting the DTC
No related DTCs.
The engine is operating in “closed loop.”
The  engine  coolant  temperature  is  above  60C
(140
F).
“Closed loop” commanded air/fuel ratio between 14.5
and 14.8.
Throttle angle between 3% and 19%.
Bank 2 HO2S 1 signal voltage remains above 952 mV
during normal “closed loop” operation for a total of 77
seconds over a 90-second period.
OR
Bank 2 HO2S 1 signal voltage remains above 500 mV
during deceleration fuel cutoff mode operation for up to
3 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.
“Open loop” fuel control will be in effect.
Conditions for Clearing the MIL/DTC
DTC P0152 can be cleared by using Tech 2 “Clear Info”
function or by disconnecting the PCM battery feed.
Diagnostic Aids
Check for the following conditions:
Fuel pressure – The system will go rich if pressure is
too  high.    The  PCM  can  compensate  for  some
increase.  However, if fuel pressure is too high, a DTC
P0152 may be set.  Refer to 
Fuel System Diagnosis.
Rich injector(s) – Perform “Injector Balance Test.”
Leaking injector – Refer to Fuel System Diagnosis.
Evaporative  emissions  (EVAP)  system  –  Check  the
canister for fuel saturation.  If the canister is full of fuel,
check  EVAP  control  system  components  and  hoses.
Refer  to 
Evaporative  Emission  (EVAP)  Control
System
. 
Page 4993 of 6000
6E–336
ENGINE DRIVEABILITY AND EMISSIONS
0016
Electrically Erasable Programmable Read
Only Memory (EEPROM)
The  electrically  erasable  programmable  read  only
memory (EEPROM) is a permanent memory chip that is
physically  soldered  within  the  PCM.    The  EEPROM
contains the program and the calibration information that
the PCM needs to control powertrain operation.
Unlike the PROM used in past applications, the EEPROM
is not replaceable.  If the PCM is replaced, the new PCM
will need to be programmed.  Equipment containing the
correct program and calibration for the vehicle is required
to program the PCM.
Fuel Control Heated Oxygen Sensors
The fuel control heated oxygen sensors (Bank 1 HO2S 1
and Bank 2 HO2S 1) are mounted in the exhaust stream
where they can monitor the oxygen content of the exhaust
gas.  The oxygen present in the exhaust gas reacts with
the  sensor  to  produce  a  voltage  output.    This  voltage
should constantly fluctuate from approximately 100 mV to
900  mV.    The  heated  oxygen  sensor  voltage  can  be
monitored with Tech 2.  By monitoring the voltage output
of the oxygen sensor, the PCM calculates the pulse width
command  for  the  injectors  to  produce  the  proper
combustion chamber mixture.
Low HO2S voltage is a lean mixture which will result in
a rich command to compensate.
High HO2S voltage is a rich mixture which will result in
a lean command to compensate.
An  open  Bank  1  HO2S  1  signal  circuit  will  set  a  DTC
P0134 and Tech 2 will display a constant voltage between
400-500  mV.    A  constant  voltage  below  300  mV  in  the
sensor  circuit  (circuit  grounded) will  set  DTC  P0131.   A
constant voltage above 800 mV in the circuit will set DTC
P0132.  Faults in the Bank 2 HO2S 1 signal circuit will
cause  DTC  0154  (open  circuit),  DTC  P0151  (grounded
circuit), or DTC P0152 (signal voltage high) to set.
0012
Intake Air Temperature (IAT) Sensor
The  intake  air  temperature  (IAT)  sensor  is  a  thermistor
which changes its resistance based on the temperature of
air entering the engine.  Low temperature produces a high
resistance  of  100,000  ohms  at  –40
C  (–40F).    High
temperature causes low resistance of 70 ohms at 130
C
(266
F) .  The PCM supplies a 5-volt signal to the sensor
through  a  resistor  in  the  PCM  and  monitors  the  signal
voltage.  The voltage will be high when the incoming air is
cold.  The voltage will be low when the incoming air is hot.
By  measuring  the  voltage,  the  PCM  calculates  the
incoming air temperature.  The IAT sensor signal is used
to  adjust  spark  timing  according  to  the  incoming  air
density.
Tech  2  displays  the  temperature  of  the  air  entering  the
engine.    The  temperature  should  read  close  to  the
ambient air temperature when the engine is cold and rise
as underhood temperature increases.  If the engine has
not been run for several hours (overnight), the IAT sensor
temperature and engine coolant temperature should read
close to each other.  A fault in the IAT sensor circuit will set
DTC P0112 or DTC P0113. 
Page 5279 of 6000
6A – 6 ENGINE MECHANICAL
SERVICE STANDARD
Enginemm (in)
Parts Items Service standard Service limit Remarks
Cylinder Head
Va l v e   S p r i n g
Valve and
Valve guide
Camshaft0.075 (0.0030) or less
95.0 (3.740)
45.7 (1.8)
—
241 (54.2)
6.959 – 6.977
(0.27 – 0.272)
6.692 – 6.970
(0.271 – 0.272)
0.023 – 0.056
(0.0009 – 0.0022)
0.03 – 0.063
(0.0011 – 0.0024)
8.0 (0.312)
1.1 (0.0433)
1.2 (0.0472)
1.2 (0.0472)
45°
2.1 (0.0827)
2.1 (0.0827)
0.08 (0.00314)
46.67 (1.8374)
46.77 (1.8413)
29.939 – 29.960
(1.167 – 1.168)
0.02 (0.0008) or less
0.40 – 0.082
(0.0016 – 0.0032)0.50 (0.0197)
—
44.8 (1.765)
1.6 (0.063)
210 (47.22)
6.92 (0.270)
6.90 (0.269)
0.19 (0.0074)
0.20 (0.0079)
—
1.6 (0.0630)
1.1 (0.0433)
1.1 (0.0433)
—
2.6 (0.1024)
2.6 (0.1024)
2.0 (0.00797)
46.57 (1.8335)
46.67 (1.8374)
29.84 (1.1748)
0.10 (0.0039)
0.12 (0.0047)Cannot be
reground Cylinder head lower surface for flatness
Cylinder head height
Free height
Squareness
Spring tension (when assembled) N(lb)
Diameter of Valve stem IN
EX
Valve and valve guide clearance IN
EX
Valve guide upper end height
(Measured from the Cylinder head upper
face)
Valve guide margin
Valve thickness IN
EX
Valve seat contact surface angle
Valve seat contact width IN
EX
End play
Cam lobe height IN
EX
Journal diameter
Runout
Camshaft oil clearance 
Page 5319 of 6000
6A – 46 ENGINE MECHANICAL
NOTE: Do not allow the camshaft to rotate.
6) Remove the camshaft bracket and measure the
plastigauge  width  and  determine  the  oil
clearance.  If  the  oil  clearance  exceeds  the
specified  limit,  replace  the  camshaft  carrier
and/or camshaft.
Oil clearance.
Standard: 0.040 – 0.082 mm (0.0016 – 0.0032 in)
Limit: 0.12 mm (0.0047 in)
7) Clean the plastigauge from the camshaft bracket
and camshaft carrier.
5. Camshaft thrust clearance.
1) Clean  the  camshaft,  camshaft  bracket  and
camshaft carrier.
2) Put camshaft carrier on the cylinder head.
3) Put camshaft on the camshaft carrier.
4) Put plastigauge on the camshaft journal.5) Install  camshaft  bracket  to  original  position  and
tighten bolts to specified torque in the numerical
order shown in the illustration.
Torque: A; 21.6 Nꞏm (2.2 kgꞏm/15.9 lb ft)
B; 38.0 Nꞏm (3.9 kgꞏm/28.2 lb ft)
C; 21.6 Nꞏm (2.2 kgꞏm/15.9 lb ft)
D; 38.0 Nꞏm (3.9 kgꞏm/28.2 lb ft)
6) Use  a  dial  indicator  to  measure  the  camshaft
thrust  clearance.  If  the  camshaft  thrust
clearance  exceeds  the  specified  limit,  replace
the camshaft carrier and/or camshaft.
Camshaft thrust clearance
Standard: 0.1 mm (0.0002 in)
Limit: 0.2 mm (0.0078 in)
13
7
6
5
1215
2
3
10
9
20
8
19
2322
4
161
11 25
24
21
17
18
011RW041
014RW185
CC
D
B
CC
B
CC
D
CC
B
C
A AA A A A
AAAA
011RW035
13
7
6
5
1215
2
3
10
9
20
8
19
2322
4
161
11 25
24
21
17
18
011RW041 
Page 5333 of 6000
6A – 60 ENGINE MECHANICAL
Valve Depression
1. Measure  the  valve  stem  height  from  the  upper
surface  of  the  cylinder  head  as  shown  in  the
illustration.
Standard: 
Intake side 35.59 mm (1.4012 in)
Exhaust side 35.49 mm (1.3972 in)
Limit:
Intake side 35.74 mm (1.4071 in)
Exhaust side 35.64 mm (1.4031 in)
Legend
(1) Intake Side
(2) Exhaust Side
Valve Contact Width
1. Check  the  valve  contact  faces  for  roughness  and
unevenness.  Make  the  valve  contact  surfaces
smooth.
2. Measure the valve contact width.
If  the  measured  value  exceeds  the  specified  limit,
the valve seat insert must be replaced.
Inlet
Standard: 2.1 mm (0.0827 in)
Limit: 2.6 mm (0.1024 in)
Exhaust
Standard: 2.0 mm (0.0787 in)
Limit: 2.5 mm (0.0984 in)
Valve Seat Insert Replacement
Valve Seat Insert Removal
1. Arc  weld  the  entire  inside  circumference  of  the
valve seat insert.
2. Allow the valve seat insert to cool for a few minutes.
This will invite contraction and make removal of the
valve seat insert easier.
3. Use a screwdriver to pry the valve seat insert free.
Take care not to damage the cylinder head.
4. Carefully remove carbon and other foreign material
from the cylinder head insert bore.
12
011RW044
014RS015 
Page 5334 of 6000
ENGINE MECHANICAL 6A – 61
Valve Seat Insert Installation
1. Carefully place the attachment (1) (having a smaller
outside  diameter  than  the  valve  seat  insert)  on  the
valve seat insert (2).
Legend
(1) Attachment
(2) Valve Seat Insert
(3) Bench Press
NOTE: The smooth side of the attachment must contact
the valve seat insert.
2. Use  a  bench  press  (3)  to  gradually  apply  pressure
to the attachment and press the valve seat insert
into place.
Note:  Do  not  apply  an  excessive  amount  of  pressure
with  the  bench  press.  Damage  to  the  valve  seat  insert
will result.
Valve Seat Insert Correction
1. Remove  the  carbon  from  the  valve  seat  insert
surface.
2. Use  a  valve  cutter  (15°,  45° and  75° blades)  to
minimize scratches and other rough areas. This will
bring the contact width back to the standard value.
Remove  only  the  scratches  and  rough  areas.  Do
not  cut  away  too  much.  Take  care  not  to  cut  away
unblemished areas of the valve seat surface.
Valve Seat Angle: 45°NOTE: Use an adjustable valve cutter pilot.
Do  not  allow  the  valve  cutter  pilot  to  wobble  inside  the
valve guide.
3. Apply  abrasive  compound  to  the  valve  seat  insert
surface.
4. Insert the valve into the valve guide.
5. Turn  the  valve  while  tapping  it  to  fit  the  valve  seat
insert.
6. Check that the valve contract width is correct.
7. Check  that  the  valve  seat  insert  surface  is  in
contact with the entire circumference of the valve.
3
2 1
012RW055
150
90
30
012RW056
014RS014 
Page 5345 of 6000
6A – 72 ENGINE MECHANICAL
7) Apply plastigage to the crankshaft journal unit as
shown in the illustration.
8) Install the main bearing caps. Apply engine oil to
the bolt threads and the seats. Tighten the bolts
to the specified torque.
Torque: 167 Nꞏm (17 kgꞏm/123 lb ft)
NOTE: Do not allow the crankshaft to rotate.
9) Remove the main bearing caps.
10) Measure the plastigage width and determine the
oil  clearance.  If  the  oil  clearance  exceeds  the
specified  limit,  replace  the  main  bearings  as  a
set and/or replace the crankshaft.
11) Clean  the  plastigage  from  the  bearings  and  the
crankshaft.
Remove the crankshaft and the bearings.
Standard: 0.031 – 0.063 mm (0.0012 – 0.0025 in)
Limit: 0.11 mm (0.0043 in)3. Run-out
1) Carefully set the crankshaft on the V-blocks.
Slowly  rotate  the  crankshaft  and  measure  the
runout.  If  the  crankshaft  runout  exceeds  the
specified limit, the crankshaft must be replaced.
Standard: 0.05 mm (0.0020 in) or less
Limit: 0.08 mm (0.0031 in)
Measure  the  diameter  and  the  uneven  wear  of
main journal and crank pin.
If  the  crankshaft  wear  exceeds  the  specified
limit, crankshaft must be replaced.
Main journal diameter
Standard: 69.917 – 69.932 mm (2.7526 – 2.7532 in)
Limit: 69.91 mm (2.7524 in)
Crank pin diameter
Standard: 52.915 – 52.930 mm (2.0833 – 2.0839 in)
Limit: 52.90 mm (2.0827 in)
Uneven wear limit
Standard: 0.05 mm (0.0020 in) or less
Limit: 0.08 mm (0.0031 in)
014RW055
014RW077
012RW068 
Page 5358 of 6000
ENGINE MECHANICAL 6A – 85
3. Measure  the  oil  clearance  between  the  connecting
rod and the crankshaft.
1) Remove  the  connecting  rod  cap  nuts  and  the
rod caps.
Arrange  the  removed  rod  caps  in  the  cylinder
number order.
2) Clean the rod bearings and the crankshaft pins.
3) Carefully check the rod bearings.
If  even  one  bearing  is  found  to  be  damaged  or
badly worn, the entire bearing assembly must be
replaced as a set. Reinstall the bearings in their
original positions.
Apply plastigage to the crank pin.
4) Reinstall the rod caps to their original positions.
5) Tighten  the  cap  nuts  in  2  steps,  using  angular
tightening  method  as  shown  in  the  following
specifications.
1st step: 29 Nꞏm (3.0 kgꞏm/22 lb ft)
2nd step: 45°– 60°NOTE: Do not allow the crankshaft to rotate
6) Remove the rod caps.
7) Measure  the  smallest  width  of  the  plastigage
and  determine  the  oil  clearance.  If  the  oil
clearance  exceeds  the  limit,  replace  the  rod
bearings as a set.
8) Clean  the  plastigage  from  the  bearings  and  the
crankshaft pins
Standard: 0.022 – 0.042 mm (0.0009 – 0.0017 in)
Limit: 0.100 mm (0.0039 in)
REASSEMBLY
1. Connecting Rod
2. Piston
3. Piston Pin
1) Apply  a  coat  of  engine  oil  to  the  piston  pin  and
the piston pin hole.
4. Piston Pin Snap Ring
1) Try  to  insert  the  piston  pin  into  the  piston  pin
hole with normal finger pressure.
2) Weight  each  piston  and  connecting  rod
assembly.
3) Select  piston  and  connecting  rod  combinations
so  that  the  weight  variation  of  the  different  four
assemblies is held within the specified limits.
Variance in weight after assembly: Less than 3g
(0.1058 oz)
NOTE:  When  changing  piston/connecting  rod
combinations,  do  not  change  the  piston/piston  pin
combination.
4) Attach the piston to the connecting rod with the
piston  front  mark  (2)  and  the  connecting  rod
front mark (3) on the same side.
014RW055
012RW075
014RW077