1988 OPEL VECTRA oil change

Wiring diagrams 12•57
12
Key to wiring diagrams for 1992 and later models (continued)
NoDescriptionTrackNoDescriptionTrack
S20.2High pressure compressor switch925
S20.3High pressure blower compressor switch939
S21Fog lamps switch555 to 557
S22Rear fog lamp switch549 to 551
S24Air conditioning blower switch904 to 911
S29Coolant temperature switch118, 137, 357, 942, 957, 972
S30Left front heating mat switch660 to 662
S31Rear left door contact switch591
S32Rear right door contact switch592
S33Traction control switch1130, 1131
S37Window lifter switch868 to 894
S37.1Left window lifter switch868 to 870
S37.2Right window lifter switch886 to 888
S37.3Left rear window lifter switch874 to 876
S37.4Right rear window lifter switch892 to 894
S37.5Safety switch872, 873
S37.6Window anti-jam off switch890
S37.7Automatic window lifter control877 to 882
S39Left rear door window lifter switch878 to 880
S40Right rear door window lifter switch896 to 898
S41Driver door burglary locking switch800 to 802
S42Passenger door central locking switch805
S44Throttle valve switch316, 317
S47Driver door contact switch593, 594
S52Hazard warning switch569 to 573
S53First gear identification switch372
S55Right front heating mat switch664 to 666
S57Sun roof switch1170 to 1183
S63Computer switch
S63.1Function reset switch856
S63.2Clock hours adjustment switch857
S63.3Function select switch858
S63.4Clock minute adjustment switch859
S64Horn switch672
S68Outside mirror switch assy
S68.1Outside mirror adjustment switch638 to 640, 758 to 762
S68.3Left/right outside mirror switch637 to 641, 759 to 763
S68.4Parking position switch765
S82Washer fluid minimum capacity control switch736
S882 stage coolant temperature switch120, 121, 137, 138, 430, 431
S89Seat belt switch998
S93Coolant minimum capacity control switch737
S95Engine oil minuimum capacity control switch738
S98Headlamps levelling switch691 to 693
S99ZV driver door window lifter switch865
S100ZV passenger door window lifter switch883
S101Compressor switch926 to 928
S102Circulation switch918 to 920
S103Transmission temperature switch350
S104Kickdown switch493
S105Start-up assistance switch495 to 497
S106Economy power program switch492
S109Acceleration revolution pressure switch921
S115Coolant temperature switch487, 488
S116Stop lamp switch564, 565
S117Hydraulic pressure switch346
S120Engine compartment hood (anti-theft warning unit) switch835
S127Calibra tail gate central locking switch831
S128Coolant temperature switch936,937S131Defroster lever limit switch918
U2Computer851 to 862
U4ABS hydroaggregate1102 to 1122, 1146 to 1164
U4.1Pump motor relay1102, 1103, 1146, 1147
U4.2Solenoid valves relay1104, 1105, 1148, 1149
U4.3Pump motor1102,1146
U4.4Diode1105,1149
U4.5Left front solenoid valve1109,1153
U4.6Right front solenoid valve1111,1155
U4.7Rear axle solenoid valve1113,1157
U4.8ABS control unit1106 to 1122, 1150 to 1164
U4.9Solenoid valves plug1109 to 1113, 1153 to 1157
U5Check control display
U5.1Washer fluid minimum capacity telltale741
U5.2Oil minimum capacity telltale740
U5.3Coolant minimum capacity telltale739
U5.4Tail light & low beam telltale738
U5.5Stop light failure telltale737
U5.6Front brake lining telltale736
U12Filter heater
U12.1Temperature switch426, 452
U12.2Filter heater427, 453
U13Automatic transmission
U13.1Solenoid valve (shift 1)481
U13.2Solenoid valve (shift 2)482
U13.3Solenoid valve (lock up control)483
U13.4Solenoid valve (pressure control)484
U17Roof antenna amplifier795
V1Brake fluid test bulb diode712
V8Air conditioning compressor diode926
X1 onWiring connectorsVarious
X10Anti theft warning unit code837
X13Diagnostic link164, 165, 189, 190, 226, 270, 271, 258, 259,
309, 310, 370, 371, 343, 344, 473, 474, 573, 725, 836, 837, 860,
861, 1012, 1013, 1069, 1070, 1118, 1119, 1136, 1162, 1163
X15Octane number plug157, 158, 182, 183, 225, 226,
257, 258, 284, 285
X54Ignition coding plug310, 311, 1014, 1070, 1071
Y1Air conditioning compressor clutch925
Y4Headlamps washer solenoid valve620
Y5Fuel solenoid valve410, 445
Y7Fuel injection valves287 to 294,320 to 327,
384 to 391,1025 to 1032,1078 to 1089
Y10Hall sensor ignition distributor153 to 158
Y11Hot start solenoid valve375, 376
Y12Charging pressure control changeover valve377, 378
Y18Exhaust gas recirculation valve1093
Y23Inductive sensor distributor201 to 208
Y24Distributor (inductive discharge)
Y25Acceleration revolution solenoid valve155, 177
Y30Cold start acceleration solenoid valve 448
Y32Fuel injection valve212, 245
Y33Ignition distributor175 to 177, 268 to 270, 238 to 240,
301 to 303, 360 to 362
Y34Tank ventilation valve293, 331, 332, 379, 380,
1092, 1016, 1017,
Y35Circulation solenoid valve918
Y44Four wheel drive solenoid valve350
Y47Park brake shift lock lifting magnet469

HEI (High Energy Ignition)
system
5This comprises of a breakerless distributor
and an electronic switching/amplifier module
along with the coil and spark plugs.
6The electrical impulse that is required to
switch off the low tension circuit is generated
by a magnetic trigger coil in the distributor. A
trigger wheel rotates within a magnetic stator,
the magnetic field being provided by a
permanent magnet. The magnetic field across
the two poles (stator arm and trigger wheel) is
dependent on the air gap between the two
poles. When the air gap is at its minimum, the
trigger wheel arm is directly opposite the
stator arm, and this is the trigger point. As the
magnetic flux between the stator arm and
trigger wheel varies, a voltage is induced in the
trigger coil mounted below the trigger wheel.
This voltage is sensed and then amplified by
the electronic module, and used to switch off
the low tension circuit. There is one trigger arm
and one stator arm for each cylinder.
7The ignition advance is a function of the
distributor, and is controlled both
mechanically and by a vacuum-operated
system. The mechanical governor mechanism
consists of two weights that move out from
the distributor shaft due to centrifugal force as
the engine speed rises. As the weights move
outwards, they rotate the trigger wheel
relative to the distributor shaft and so
advance the spark. The weights are held in
position by two light springs, and it is the
tension of the springs that is largely
responsible for correct spark advancement.
8The vacuum control consists of a
diaphragm, one side of which is connected by
way of a small-bore hose to the carburettor,
and the other side to the distributor.
Depression in the inlet manifold and
carburettor, which varies with engine speed
and throttle position, causes the diaphragm to
move, so moving the baseplate and
advancing or retarding the spark. A fine
degree of control is achieved by a spring in
the diaphragm assembly.
MSTS-i (Microprocessor-
controlled Spark Timing System)
9This system comprises a “Hall-effect”
distributor (or a crankshaft speed/position
sensor on X 16 SZ models), a manifold pressure
sensor, an oil temperature sensor, and a
module, along with the coil and spark plugs.
10On 1.6 litre models, the electrical impulse
that is required to switch off the low tension
circuit is generated by a sensor in the
distributor. A trigger vane rotates in the gap
between a permanent magnet and the sensor.
The trigger vane has four cut-outs, one for
each cylinder. When one of the trigger vane
cut-outs is in line with the sensor, magnetic
flux can pass between the magnet and the
sensor. When a trigger vane segment is in line
with the sensor, the magnetic flux is diverted
through the trigger vane away from thesensor. The sensor senses the change in
magnetic flux, and sends an impulse to the
MSTS-i module, which switches off the low
tension circuit.
11On 1.8 litre models, the electrical impulse
that is required to switch off the low tension
circuit is generated by a crankshaft
speed/position sensor, which is activated by a
toothed wheel on the crankshaft. The toothed
wheel has 35 equally spaced teeth, with a gap
in the 36th position. The gap is used by the
sensor to determine the crankshaft position
relative to TDC (top dead centre) of No 1 piston.
12Engine load information is supplied to the
MSTS-i module by a pressure sensor, which
is connected to the carburettor by a vacuum
pipe. Additional information is supplied by an
oil temperature sensor. The module selects
the optimum ignition advance setting based
on the information received from the sensors.
The degree of advance can thus be constantly
varied to suit the prevailing engine conditions.
Multec, with MSTS-i
13The ignition system is fully electronic in
operation and incorporates the Electronic
Control Unit (ECU) mounted in the driver’s
footwell. A distributor (driven off the camshaft
left-hand end and incorporating the amplifier
module) as well as the octane coding plug,
the spark plugs, HT leads, ignition HT coil and
associated wiring.
14The ECU controls both the ignition system
and the fuel injection system, integrating the
two in a complete engine management
system. Refer to Chapters 4B and 4C for
further information that is not detailed here.
15For ignition the ECU receives information
in the form of electrical impulses or signals
from the distributor (giving it the engine speed
and crankshaft position), from the coolant
temperature sensor (giving it the engine
temperature) and from the manifold absolute
pressure sensor (giving it the load on the
engine). In addition, the ECU receives input
from the octane coding plug (to provide
ignition timing appropriate to the grade of fuel
used) and from, where fitted, the automatic
transmission control unit (to smooth gear
changing by retarding the ignition as changes
are made).
16All these signals are compared by the
ECU with set values pre-programmed
(mapped) into its memory. Considering this
information, the ECU selects the ignition
timing appropriate to those values and
controls the ignition HT coil by way of the
amplifier module accordingly.
17The system is so sensitive that, at idle
speed, the ignition timing may be constantly
changing; this should be remembered if trying
to check the ignition timing.
18The system fitted to C18 NZ models, is
similar to that described above, except that
the amplifier module is separate. The ECU
determines engine speed and crankshaft
position using a sensor mounted in the
right-hand front end of the engine’s cylinderblock; this registers with a 58-toothed disc
mounted on the crankshaft so that the gap left
by the missing two teeth provides a reference
point, so enabling the ECU to recognise TDC.
19Note that this simplifies the distributor’s
function, which is merely to distribute the HT
pulse to the appropriate spark plug; it has no
effect whatsoever on the ignition timing.
DIS (Direct Ignition System)
20On all X16 SZ engines, and on C20 XE
(DOHC) engines from 1993-on, a DIS (Direct
Ignition System) module is used in place of
the distributor and coil. On the X16 SZ engine
the DIS module is attached to the camshaft
housing in the position normally occupied by
the distributor. On the C20 XE engine, a
camshaft phase sensor is attached to the
cylinder head at the non-driven end of the
exhaust camshaft, in the position normally
occupied by the distributor. The DIS module
is attached, by a bracket, to the cylinder head
at the non-driven end of the inlet camshaft.
21The DIS module consists of two ignition
coils and an electronic control module housed
in a cast casing. Each ignition coil supplies
two spark plugs with HT voltage. One spark is
provided in a cylinder with its piston on the
compression stroke, and one spark is
provided to a cylinder with its piston on the
exhaust stroke. This means that a “wasted
spark” is supplied to one cylinder during each
ignition cycle, but this has no detrimental
effect. This system has the advantage that
there are no moving parts (therefore there is
no wear), and the system is largely
maintenance-free.
Motronic M4.1 and M1.5
22This system controls both the ignition and
the fuel injection systems.
23The Motronic module receives information
from a crankshaft speed/position sensor, an
engine coolant temperature sensor mounted
in the thermostat housing. A throttle position
sensor, an airflow meter, and on models fitted
with a catalytic converter, an oxygen sensor
mounted in the exhaust system (Chapter 4C).
24The module provides outputs to control
the fuel pump, fuel injectors, idle speed and
ignition circuit. Using the inputs from the
various sensors, the module computes the
optimum ignition advance, and fuel injector
pulse duration, to suit the prevailing engine
conditions. This system gives very accurate
control of the engine under all conditions,
improving fuel consumption and driveability,
and reducing exhaust gas emissions.
25Further details of the fuel injection system
components are given in Chapter 4B.
Motronic M2.5 and M2.8
26The system is similar to that described for
SOHC models, with the following differences.
27Along with the crankshaft speed/position
sensor, a “Hall-effect” distributor is used
(similar to that described in this Section, with
the MSTS-i system).
Engine electrical systems 5•3
5

2When the starter switch is operated, current
flows from the battery to the solenoid that is
mounted on the starter body. The plunger in
the solenoid moves inwards, so causing a
centrally pivoted lever to push the drive pinion
into mesh with the starter ring gear. When the
solenoid plunger reaches the end of its travel,
it closes an internal contact and full starting
current flows to the starter field coils. The
armature is then able to rotate the crankshaft,
so starting the engine.
3A special freewheel clutch is fitted to the
starter driven pinion, so that when the engine
fires and starts to operate on its own it does
not drive the starter motor.
4When the starter switch is released, the
solenoid is de-energised, and a spring moves
the plunger back to its rest position. This
operates the pivoted lever to the withdraw the
drive pinion from engagement with the starter
ring.
13Starter motor - testing
3
Note: Refer to Section 3 before proceeding
Testing
1If the starter motor fails to turn the engine
when the switch is operated, and engine
seizure is not the problem, there are several
other possible reasons:
a)The battery is faulty
b)The electrical connections between the
switch, solenoid battery and starter motor
are somewhere failing to pass the
necessary current from the battery
through the starter to earth
c)The solenoid switch is faulty
d)The starter motor is mechanically or
electrically defective
e)The starter motor pinion and/or flywheel
ring gear is badly worn, and in need of
replacement
2To check the battery, switch on the
headlamps. If they dim after a few seconds,
then the battery is in a discharged state. If the
lamps glow brightly, operate the starter switch
and see what happens to the lamps. If theydim, then power is reaching the motor, but
failing to turn it. If the starter turns slowly, go
on to the next check.
3If, when the starter switch is operated, the
lamps stay bright, then insufficient power is
reaching the motor. Disconnect the battery
and the starter/solenoid power connections,
and the engine earth strap, then thoroughly
clean them and refit them. Smear petroleum
jelly around the battery connections to
prevent corrosion. Corroded connections are
the most frequent cause of electrical system
malfunctions.
4If the preceding checks and cleaning tasks
have been carried out without success, a
clicking noise will probably have been heard
each time the starter switch was operated.
This indicates that the solenoid switch was
operating, but it does not necessarily follow
that the main contacts were closing properly
(if no clicking has been heard from the
solenoid, it is certainly defective). The
solenoid can be checked by connecting a
voltmeter across the main cable connection
on the solenoid and earth. When the switch is
operated, these should be a reading on the
voltmeter. If there is no reading, the solenoid
unit is faulty, and should be renewed.
5If the starter motor operates, but does not
turn the engine, then it is likely that the starter
pinion and/or flywheel ring gear are badly
worn. If this is the case, the starter motor will
normally be noisy in operation.
6Finally, if it is established that the solenoid
is not faulty, and 12 volts are reaching the
starter, then the motor itself is faulty, and
should be removed for inspection.
14Starter motor - removal and
refitting
3
Note: Refer to Section 3 before proceeding
Removal
1Disconnect the battery negative lead.
2Apply the handbrake, then jack up the front
of the vehicle, and support securely on axle
stands (see “Jacking and Vehicle Support”)
positioned under the body side members.3On DOHC models, remove the engine
undershield, as described in Chapter 11.
4Note the wiring connections on the
solenoid, then disconnect them (see
illustration).
5Where applicable, unscrew the bolt
securing the exhaust bracket and the starter
motor mounting bracket to the cylinder block
(see illustration).
6Unscrew the two starter motor mounting
bolts. Note that the top bolt on some models
are fitted from the transmission side, and
secures a wiring harness bracket (see
illustration).
7Withdraw the starter motor.
Refitting
8Refitting is a reversal of removal, but where
applicable, ensure that the wiring harness
bracket is in place on the top mounting bolt,
and tighten all bolts to the specified torque.
15Starter motor - overhaul
5
If the starter motor is thought to be suspect,
it should be removed from the vehicle and
taken to an auto-electrician for testing. Most
auto-electricians will be able to supply and fit
brushes at a reasonable cost. However, check
on the cost of repairs before continuing as it
may prove more economical to obtain a new
or exchange motor.
16Ignition coil - removal, testing
and refitting
3
Note: Refer to Section 3 before proceeding.
An ohmmeter will be required to test the coil
Removal
1The ignition coil is either a cylindrical metal
canister or a moulded plastic unit. It is
clamped or bolted to the left-hand inner wing
panel, near the suspension strut top mounting
(under the power steering fluid reservoir, on
Engine electrical systems 5•9
14.6 Starter motor securing bolts
(arrowed) - 1.6 litre model
(engine removed)14.5 Starter motor mounting
bracket/exhaust bracket securing bolt
(arrowed) - 1.6 litre model14.4 Starter motor and solenoid viewed
from underneath the vehicle. Solenoid
wiring connections arrowed
5

in a clip at the left-hand rear of the engine
compartment (see illustration).
4The plug is reversible in its connector, and
is marked either “A” or “98” on one side,
which corresponds to the position for use with
98 RON leaded petrol. On the other side either
“B” or “95”, which corresponds to the position
to use with 95 RON unleaded petrol. All
vehicles are set for use with 95 RON unleaded
petrol before they leave the factory.
5To change the coding for use with a
different type of petrol, first allow the fuel tank
to become practically empty.
6Fill the fuel tank with the required type of
petrol.
7Ensure that the ignition is switched off, then
remove the coding plug from its clip and
disconnect the wiring connector.
8Rotate the plug through 180°, so that the
appropriate octane mark is uppermost (see
paragraph 4), then reconnect the wiring
connector and refit the plug to its clip.
9Note that using petrol with a higher octane
rating than that set will not cause damage, but
petrol with a lower octane rating than that set
must not be used.
20 XE, C20 XE and X20 XEV
models
10The ignition coding plug found on these
models is not an octane coding plug
(although its method of operation is similar)
and must not be altered from its factory
setting. Its purpose is to ensure that the
Motronic module uses the correct information,
pre-programmed (or “mapped”) into its
memory, to enable the vehicle to comply with
the relevant national noise and exhaust
emission legislation.
11On these models, the knock sensor circuit
allows the Motronic module to compensate
for differences in the octane value of the
petrol used, without the need for manual
intervention. Remember, however, that all
catalytic converter-equipped vehicles must
use unleaded petrol only. This means that
these models can use any grade of unleaded
petrol on sale in the UK without the need for
adjustment.
23Electronic modules - removal
and refitting
3
Note: Refer to Section 3 for precautions to be
observed when working with electronic
modules. Heat sink compound must be used
when refitting the module.
HEI module (14 NV models)
Removal
1The module is mounted on a metal plate,
beneath the ignition coil, on the left-hand side
of the engine compartment.
2Remove the ignition coil as described in
Section 16, and slide the coil from its clamp.
3The module can be removed from the
mounting plate by unscrewing the two
securing screws.
4Before refitting the module, heat sink
compound should be applied to the mounting
plate to improve heat dissipation. If a new
module is being fitted, it should be supplied
with heat sink compound. Similar compounds
can be bought from DIY electrical shops.
Refitting
5Refitting is a reversal of removal.
MSTS-i module (1.6 and 1.8 litre
models)
Removal
6The module is mounted on the engine
compartment bulkhead, above the steering
rack (see illustration).
7Disconnect the battery negative lead.
8If desired, for improved access, remove the
air box from the top of the carburettor.
9Disconnect the wiring plug from the
module.
10Unscrew the two securing nuts, and
withdraw the module from the bulkhead.
Refitting
11Refitting is a reversal of removal.
Motronic module
Removal
12The module is mounted in the driver’s
footwell, behind the side trim panel.13Disconnect the battery negative lead.
14Remove the driver’s footwell side trim
panel, as described in Chapter 11.
15Unscrew the three module securing
screws, two at the top of the module, and a
single screw at the bottom, and lower the
module from the footwell (see illustration).
16Release the retaining clip, and disconnect
the module wiring plug (see illustration).
17Withdraw the module, noting the plastic
insulating sheet on its rear face.
Refitting
18Refitting is a reversal of removal, but
ensure that the insulating sheet is in place on
the rear face of the module.
24MSTS-i components -
removal and refitting
3
Note: Refer to Section 3 before proceeding.
Procedures for removal and refitting of the
ignition system components and electronic
module are given elsewhere in the relevant
Sections of this Chapter
Manifold pressure sensor
Removal
1The sensor is located on the engine
compartment bulkhead, to the left of the
MSTS-i module, under the edge of the
windscreen cowl panel (see illustration).
2Disconnect the battery negative lead.
5•14Engine electrical systems
22.3 Octane coding plug (arrowed) -
2.0 litre model
23.15 Lowering the Motronic module from
the footwell - 2.0 litre model23.16 Releasing the Motronic module
wiring plug clip - 2.0 litre model
23.6 MSTS-i module location -
1.6 litre model

2Exhaust gas recirculation
(EGR) system - general
The system reintroduces small amounts of
exhaust gas into the combustion cycle to
reduce the generation of oxides of nitrogen
(NOx).
On C16 NZ, C16 NZ2 and C18 NZ engines,
the volume of exhaust gas reintroduced is
governed by manifold vacuum, through the
EGR valve mounted on the inlet manifold.
When the valve is opened small amounts of
exhaust gas are allowed to enter the inlet
tract, passing through ports in the cylinder
head.
On X16 SZ engines the EGR valve is
operated by an EGR module, mounted on the
left-hand side of the engine compartment
behind the battery. This module amplifies
signals received from the fuel system ECU
and operates the EGR valve electronically
providing precise control of exhaust gas
recirculation under all engine conditions.
3EGR valve (Multec system
models) - testing, removal and
refitting
2
Testing
1On C16 NZ, C16 NZ2 and C18 NZ engines,
it is recommended that the system is checked
annually, by checking the movement of the
valve’s diaphragm carrier plate as follows.
Note that the carrier plate is visible only
through the apertures in the underside of the
valve, so a battery-operated torch and small
mirror may be useful. On X16 SZ engines,
Vauxhall test equipment is necessary to check
the EGR system.
2With the engine fully warmed up to normal
operating temperature and idling, briefly open
and close the throttle. The carrier plate should
move upwards as the manifold vacuum
changes. When the engine is idling smoothly
again, press the carrier plate upwards (do this
very carefully, so that the plate is not distorted or
the diaphragm damaged). The idle speed should
drop significantly (approximately 100 rpm).
3If the valve does not respond as described,
it must be cleaned.
Removal
4Pull off the hose from the valve, then unbolt
the valve and remove it (see illustrations).
Clean away all carbon using a wire brush and
a pointed tool, but take care not to damage
the valve seat. Renew the valve gasket to
prevent induction leaks.
Refitting
5Refit the valve and reconnect the hose,
then recheck the system’s performance; if
there is no improvement, the valve must be
renewed.
4EGR valve (Simtec system) -
testing, removal and refitting
3
Note: A new gasket will be required when
refitting the valve.
Removal
1Disconnect the battery negative lead.
2Remove wiring harness and vacuum hose.
3Mark position of the valve, to ensure
correct relocation.
4Undo the 3 bolts, and remove the valve
from the dual spark ignition coil’s coolant
flange.
Refitting
5Clean the sealing surfaces of the valve and
flange.
6Refit the valve with a new gasket and line
up the marks made before removal (see
illustration).
5EGR module (X16 SZ
models) - removal and
refitting
2
Removal
1Disconnect the knock module from its
bracket (refer to Chapter 4B, if necessary),
and place to one side.
2Remove wiring plug from module. Remove
module from bracket.
Refitting
3Refitting is a reversal of removal.
6AIR pump assembly (Simtec
system) - removal and refitting
3
Removal
1Chock the rear wheels, jack up the front of
the vehicle and support it on axle stands
placed under the body side members (see
“Jacking and Vehicle Support”)
2Remove the left hand front wheel and inner
wheel arch lining.
3Loosen the hose clamp and remove the air
duct hose from the pump.
4Disconnect the battery negative lead.
5Undo the securing nuts and remove the
pump assembly from its location. Disconnect
the wiring plug.
6Remove the wiring plug from the pump’s
bracket.
7Mark the position of the pump on it’s
bracket before separating.
8Remove the fixing bolts and disconnect the
pump from it’s insulator.
9The insulator can also be checked by
removing the 3 nuts, securing the protective
shield. Before removing, mark the shield and
insulator. Replace if necessary.
10Check the pump’s air cleaner for damage.
Refitting
11Refitting is a reversal of removal. Ensure
correct alignment of the components.
7AIR cut-off valve - removal,
testing and refitting
3
Removal
1Before removal, mark on the cut-off valve,
the direction of flow towards the non-return
valve (see illustration).
2Disconnect and remove the air duct and
vacuum hoses.
3Undo the switchover valve’s bolts and
move to one side.
4C•2Fuel and exhaust systems - exhaust and emissions
3.4 Disconnecting the vacuum hose from
the exhaust gas recirculation valve
4.6 EGR valve
1 Valve 2 Gasket
3.4B Withdrawing the exhaust gas
recirculation valve

b)Always keep the ignition and fuel systems
well maintained according to the
manufacturers schedule (see “Routine
maintenance” and the relevant Chapter).
In particular, ensure that the air cleaner
filter element, the fuel filter and the spark
plugs are renewed at the correct intervals.
If the inlet air/fuel mixture is allowed to
become too rich due to neglect, the
unburned surplus will enter and burn in
the catalytic converter, overheating the
element and eventually destroying the
converter.
c)If the engine develops a misfire, do not
drive the vehicle at all (or at least as little
as possible) until the fault is cured. The
misfire will allow unburned fuel to enter
the converter, which will result in its
overheating, as noted above.
d)The engine control indicator (the outline
of an engine with a lightning symbol
superimposed), will light when the ignition
is switched on and the engine is started,
then it will go out. While it may light briefly
while the engine is running, it should go
out again immediately and stays unlit. If it
lights and stays on while the engine is
running, seek the advice of a Vauxhall
dealer as soon as possible. A fault has
occurred in the fuel injection/ignition
system that, apart from increasing fuel
consumption and impairing the engine’s
performance, may damage the catalytic
converter.
e)DO NOT push or tow-start the vehicle.
This will soak the catalytic converter in
unburned fuel causing it to overheat when
the engine does start see (b) above.
f)DO NOT switch off the ignition at high
engine speeds. If the ignition is switched
off at anything above idle speed,
unburned fuel will enter the (very hot)
catalytic converter, with the possible risk
of its igniting on the element and
damaging the converter.
g)DO NOT use fuel or engine oil additives.
These may contain substances harmful to
the catalytic converter.
h)DO NOT continue to use the vehicle if the
engine burns oil to the extent of leaving a
visible trail of blue smoke. The unburned
carbon deposits will clog the converter
passages and reduce its efficiency; in
severe cases the element will overheat.
i)Remember that the catalytic converter
operates at very high temperatures hence
the heat shields on the vehicle’s under-
body and the casing will become hot
enough to ignite combustible materials
that brush against it. DO NOT, therefore,
park the vehicle in dry undergrowth, over
long grass or over piles of dead leaves.
j)Remember that the catalytic converter is
FRAGlLE. Do not strike it with tools during
servicing work. Take great care when
working on the exhaust system. Ensure
that the converter is well clear of any
jacks or other lifting gear used to raise thevehicle. Do not drive the vehicle over
rough ground, road humps, etc., in such a
way as to ground the exhaust system.
k)In some cases, particularly when the
vehicle is new and/or is used for
stop/start driving, a sulphurous smell (like
that of rotten eggs) may be noticed from
the exhaust. This is common to many
catalytic converter-equipped vehicles and
seems to be due to the small amount of
sulphur found in some petrol’s reacting
with hydrogen in the exhaust to produce
hydrogen sulphide (CS) gas. While this
gas is toxic, it is not produced in sufficient
amounts to be a problem. Once the
vehicle has covered a few thousand miles
the problem should disappear. In the
meanwhile a change of driving style or of
the brand of petrol may effect a solution.
l)The catalytic converter, used on a
well-maintained and well-driven vehicle,
should last for between 50 000 and 100
000 miles. From this point on, careful
checks should be made at all specified
service intervals of the CO level to ensure
that the converter is still operating
efficiently. If the converter is no longer
effective it must be renewed.
11Carbon canister - removal
and refitting
3
Removal
1Apply the handbrake, then jack up the front
of the vehicle, and support securely on axle
stands placed under the body side members
(see “Jacking and Vehicle Support”).
2Remove the front right hand wheel and
wheel arch liner.
3Note the hose and pipe connections to the
canister, or label them, to ensure that they are
reconnected to their original unions, then
disconnect them (see illustration). Unscrew
the two nuts securing the canister mounting
bracket to the vehicle body.
Refitting
4Refitting is a reversal of removal, however
ensure correct fitment of hose and pipes.
12Oxygen sensor (catalytic
converter models) - removal
and refitting
3
Note: This sensor is also known as a Lambda
sensor.
Removal
1Disconnect the battery negative lead.
2Disconnect the oxygen sensor wiring plug,
which is located behind the coolant expansion
tank.
3Apply the handbrake, then jack up the front
of the vehicle, and support securely on axle
stands placed under the body side members.
4On DOHC models, remove the engine
undershield, as described in Chapter 11.
5On models fitted with Multec injection
system, the sensor is screwed into the
exhaust manifold. Trace the wiring from the
sensor itself to the connector (either clipped
to the radiator cooling fan shroud or behind
the coolant expansion tank). Release it from
any clips or ties; disconnect the wiring before
unscrewing the sensor.
6On other models, unscrew the oxygen
sensor from the front section of the exhaust
system (see illustration). It is advisable to
wear gloves, as the exhaust system will be
extremely hot.
7Withdraw the oxygen sensor and its wiring,
taking care not to burn the wiring on the
exhaust system. If the sensor is to be re-used,
take care that the sealing ring is not lost, and
that the sensor is not dropped.
Refitting
8If a new sensor is being fitted, it will be
supplied with the threads coated in a special
grease to prevent it seizing in the exhaust
system.
9If the original sensor is being refitted,
ensure that the screw thread is clean. Coat
the thread with a lithium based copper grease
(i.e. Vauxhall Part No. 90295397).
10Refitting is a reversal of removal. Check
the exhaust system for leakage when the
engine is re-started.
4C•4Fuel and exhaust systems - exhaust and emissions
12.6 Oxygen sensor location in front
section of exhaust system - DOHC models
11.3 Charcoal canister
A Vent to atmosphere
B Vapour feed hose from filler pipe
C Vapour exhaust hose to inlet tract
D Control valve vacuum pipe from
throttle body

4B
cruising and accelerating. The injector earth is
also switched off on the overrun to improve
fuel economy and reduce exhaust emissions.
Additionally, on the X16 SZ engine, the ECU
also controls the operation of the charcoal
canister purge valve in the evaporative
emission control system.
10The oxygen sensor screwed into the
exhaust manifold provides the ECU with a
constant feedback signal. This enables it to
adjust the mixture (closed-loop control) to
provide the best possible conditions for the
catalytic converter to operate effectively.
11Until the oxygen sensor is fully warmed up
it gives no feedback so the ECU uses
pre-programmed values (open-loop control) to
determine the correct injector pulse width.
When the sensor reaches its normal operating
temperature, its tip (which is sensitive to
oxygen) sends the ECU a varying voltage
depending on the amount of oxygen in the
exhaust gases. If the inlet air/fuel mixture is too
rich, the exhaust gases are low in oxygen so the
sensor sends a low-voltage signal. The voltage
rises as the mixture weakens and the amount of
oxygen rises in the exhaust gases. Peak
conversion efficiency of all major pollutants
occurs if the inlet air/fuel mixture is maintained
at the chemically correct ratio for the complete
combustion of petrol of 14.7 parts (by weight) of
air to 1 part of fuel (the “stoichiometric” ratio).
The sensor output voltage alters in a large step
at this point, the ECU using the signal change
as a reference point and correcting the inlet
air/fuel mixture accordingly by altering the fuel
injector pulse width.
12In addition, the ECU senses battery
voltage, incorporates diagnostic capabilities,
and can both receive and transmit information
by way of the diagnostic connector, thus
permitting engine diagnosis and tuning by
Vauxhall’s TECH1, test equipment.
Motronic system
13The Motronic type is available in several
different versions, depending on model. The
system is under the overall control of the
Motronic engine management system (Chapter
5), which also controls the ignition timing.
14Fuel is supplied from the rear-mounted
fuel tank by an electric fuel pump mounted
under the rear of the vehicle, through a
pressure regulator, to the fuel rail. The fuel rail
acts as a reservoir for the four fuel injectors,
which inject fuel into the cylinder inlet tracts,
upstream of the inlet valves. On SOHC
engines, the fuel injectors receive an electrical
pulse once per crankshaft revolution, which
operates all four injectors simultaneously. On
DOHC engines, sequential fuel injection is
used, whereby each injector receives an
individual electrical pulse allowing the four
injectors to operate independently, which
enables finer control of the fuel supply to each
cylinder. The duration of the electrical pulse
determines the quantity of fuel-injected, and
pulse duration is computed by the Motronic
module, based on the information received
from the various sensors.15On SOHC engines, inlet air passes from
the air cleaner through a vane type airflow
meter, before passing to the cylinder inlet
tracts through the throttle valve. A flap in the
vane airflow meter is deflected in proportion
to the airflow; this deflection is converted into
an electrical signal, and passed to the
Motronic module. A potentiometer screw
located on the airflow meter provides the
means of idle mixture adjustment, by altering
the reference voltage supplied to the Motronic
module.
16On DOHC engines, inlet air passes from
the air cleaner through a hot wire type air
mass meter, before passing to the cylinder
inlet tracts through a two-stage throttle body
assembly. The electrical current required to
maintain the temperature of the hot wire in the
air mass meter is directly proportional to the
mass flow rate of the air trying to cool it. The
current is converted into a signal, which is
passed to the Motronic module. The throttle
body contains two throttle valves that open
progressively, allowing high torque at part
throttle, and full-throttle, high-speed
“breathing” capacity. A potentiometer screw
located on the air mass meter provides the
means of idle mixture adjustment, by altering
the reference voltage supplied to the Motronic
module.
17A throttle position sensor enables the
Motronic module to compute the throttle
position, and on certain models, its rate of
change. Extra fuel can thus be provided for
acceleration when the throttle is opened
suddenly. Information from the throttle
position sensor is also used to cut off the fuel
supply on the overrun, thus improving fuel
economy and reducing exhaust gas
emissions.
18Idle speed is controlled by a variable-
orifice solenoid valve, which regulates the
amount of air bypassing the throttle valve. The
valve is controlled by the Motronic module;
there is no provision for direct adjustment of
the idle speed.
19Additional sensors inform the Motronic
module of engine coolant temperature, air
temperature, and on models fitted with a
catalytic converter, exhaust gas oxygen
content.
20A fuel filter is incorporated in the fuel
supply line, to ensure that the fuel supplied to
the injectors is clean.
21A fuel pump cut-off relay is controlled by
the Motronic module, which cuts the power to
the fuel pump should the engine stop with the
ignition switched on, if there is an accident. All
1993-onwards models equipped with
Motronic systems, have their fuel pump
located inside the fuel tank.
22The later M2.8 system is basically the
same as the earlier M2.5 system apart from
the following:
a)Hot Film Mass Airflow Meter - The hot
wire type unit used previously is replaced
on the M2.8 system by a hot film mass
airflow meter. The operation is the sameexcept that a thin, electrically heated plate
rather than a wire is used. The plate is
maintained at a constant temperature by
electric current as the inlet air mass
passing over the plate tries to cool it. The
current required to maintain the
temperature of the plate is directly
proportional to the mass flow rate of the
inlet air. The current is converted to a
signal that is passed to the Motronic
module.
b)Inlet Air Temperature Sensor -The sensor
is located in the hose between the hot
film mass airflow meter and the air cleaner
for precise monitoring of inlet air
temperature. Signals from the sensor are
used in conjunction with other sensors to
indicate the occurrence of a hot start
condition. The Motronic module then
interprets these signals to alter injector
duration accordingly.
c)Throttle Valve Potentiometer -On the
M2.8 system a throttle valve
potentiometer replaces the throttle valve
switch used previously.
Simtec system
23An increased amount of electronic
components are used instead of mechanical
parts as sensors and actuators with the
Simtec engine management system. This
provides more precise operating data as well
as greater problem free motoring.
24The control unit is equipped with
electronic ignition control. Called ‘Micropro-
cessor Spark Timing System, inductive
triggered’, (or MSTS-i), and means that the
mechanical high voltage distributor is no
longer needed. It is located behind the trim
panel, on the right-hand side footwell (door
pillar).
25The ignition coil is replaced by a dual
spark ignition coil, which is switched directly
by the output stages in the control unit.
26A camshaft sensor will maintain
emergency operation, should the crankshaft
inductive pulse pick-up, malfunction. These
sense TDC (‘Top Dead Centre’), crankshaft
angle and engine speed. The signals are used
by the control unit to calculate ignition point
and for fuel injection.
27The ‘hot film airflow meter’ determines the
mass of air taken in by the engine. The system
uses this information to calculate the correct
amount of fuel needed for injection in the
engine.
28The air inlet temperature sensor (NTC), is
fitted in the air inlet duct between the air
cleaner and the hot mass air flow meter.
29A controlled canister purge valve is
actuated by the system. The tank ventilation is
monitored closely with the Lambda control (or
oxygen sensor) and adaptation by the
computer within the control unit.
30A knock control system is also fitted. This
eliminates the need for octane number
adjustment, as it is performed automatically
through the control unit.
Fuel and exhaust systems - fuel injection models 4B•3

Lubricants and fluids
Refer to “Weekly Checks”
Capacities
Engine oil
Including filter:
1.4 litre . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3.0 litres
1.6 litre . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3.5 litres
1.8 and 2.0 litre SOHC models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4.0 litres
20 XEJ and C 20 XE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4.5 litres
X 20 XEV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4.0 litres
Quantity of oil required to raise level on dipstick from “MIN” to “MAX”:
1.4 litre . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.8 litre
All other models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.0 litre
Cooling system (approx.)
1.4 litre models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5.6 litres
1.6 litre models (except C 16 NZ2) - manual transmission . . . . . . . . . .5.8 litres
1.6 litre models (except C 16 NZ2) - automatic transmission . . . . . . . .5.6 litres
C 16 NZ2, 1.8 and 2.0 litre SOHC models - manual transmission . . . . .7.2 litres
C 16 NZ2, 1.8 and 2.0 litre SOHC models - automatic transmission . . .7.1 litres
DOHC models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7.2 litres
Transmission
Manual transmission codes:
F10 and F13 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.6 litres
F16, F18 and F20 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.9 litres
Automatic - at fluid change . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3.0 to 3.5 litres
Difference between dipstick MAX and MIN marks -approximate:
+ 20°C side . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.25 litre
+ 80°C side . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.40 litre
Power steering fluid
Approximately . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.0 litre
Fuel tank
All models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .63.0 ±2 litres
Washer fluid
Without headlamp washers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2.6 litres
With headlamp washers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4.5 litres
Engine
Oil filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Champion G102
Cooling system
Antifreeze mixture:
28% antifreeze . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Protection down to -15°C (5°F)
50% antifreeze . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Protection down to -30°C (-22°F)
Note:
Refer to antifreeze manufacturer for latest recommendations.
Fuel system
Note:Ignition timing adjustment is not possible on some models, shown for information only.
For further details refer to Chapters 4A or 4B, as applicable.
Idle speed:
14 NV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .925 ±25 rpm
16 SV
Manual transmission models . . . . . . . . . . . . . . . . . . . . . . . . . . . . .925 ±25 rpm
Automatic transmission models . . . . . . . . . . . . . . . . . . . . . . . . . . .825 ±25 rpm
18 SV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .925 ±25 rpm
C 16 NZ and X 16 SZ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .850 ±80 rpm
C 16 NZ2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .880 ±80 rpm
C 18 NZ
Manual transmission models . . . . . . . . . . . . . . . . . . . . . . . . . . . . .880 ±80 rpm
Automatic transmission models . . . . . . . . . . . . . . . . . . . . . . . . . . .830 ±80 rpm
20 NE, C 20 NE and 20 SEH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .800 ±80 rpm
20 XEJ and C 20 XE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .940 ±80 rpm
X 20 XEV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .850 ±160 rpm
1•2Servicing Specifications