1991 BMW 5 SERIES Check control

19After adjustment, screw the stop pads in
or out to support the bonnet in its new
position (see illustration).
20The bonnet mechanism should be
lubricated periodically with grease, to prevent
sticking or jamming.
11 Bumpers-
removal and refitting
1
Removal
1Detach the bumper cover (if applicable) and
where necessary the front spoiler.
2Disconnect any wiring or other components
that would interfere with bumper removal.
3Support the bumper with a jack or axle
stand. Alternatively, have an assistant support
the bumper as the bolts are removed.
4Remove the retaining bolts and detach the
bumper.
Refitting
5Refitting is a reversal of removal. Tighten
the retaining bolts securely, then refit the
bumper cover and any other components that
were removed.
12 Door trim panel-
removal and refitting
1
Caution: If the radio in your
vehicle is equipped with an anti-
theft system, make sure you have
the correct activation code before
disconnecting the battery, Refer to the
information on page 0-7 at the front of this
manual before detaching the cable.
Note: If, after connecting the battery, the
wrong language appears on the instrument
panel display, refer to page 0-7 for the
language resetting procedure.
Removal
1Disconnect the battery negative cable.
2Remove all door trim panel retaining screws
and door pull/armrest assemblies.3On models with manual (non-electric)
windows, remove the window regulator
handle (see illustration). On models with
electric windows, prise off the control switch
assembly and unplug it.
4Disengage the trim panel-to-door retaining
clips. Work around the outer edge until the
panel is free.
5Once all of the clips are disengaged, detach
the trim panel, unplug any electrical
connectors, and remove the trim panel from
the vehicle.
6For access to the inner door, carefully peel
back the plastic water shield.
Refitting
7Prior to refitting the door trim panel, be sure
to renew any clips in the panel which may
have come out (or got broken) during the
removal procedure.
8Plug in the electrical connectors (where
applicable) and place the panel in position in
the door. Press the door panel into place until
the clips are seated, then refit the
armrest/door pulls. Refit the window regulator
handle, where applicable.
13 Door- removal, refitting and
adjustment
1
Removal
1Remove the door trim panel (see Section
12). Disconnect any electrical connectors, andpush them through the door opening so they
won’t interfere with door removal.
2Place a trolley jack or axle stand under the
door, or have an assistant on hand to support
it when the hinge bolts are removed. Note: If a
jack or axle stand is used, place a rag between
it and the door, to protect the door’s painted
surfaces.
3Scribe or mark around the door hinges.
4Disconnect the door check strap by prising
the circlip out of the end of the pin, then slide
the pin out (see illustration). A roll pin is fitted
to some models; this is removed by driving it
out with a pin punch.
5Remove the hinge-to-door nuts, and
carefully lift off the door (see illustration).
Refitting and adjustment
6Refitting is the reverse of removal.
7Following refitting of the door, check the
alignment and adjust it if necessary as
follows:
a) Up-and-down and fore-and-aft
adjustments are made by loosening the
hinge-to-body nuts and moving the door
as necessary.
b) The door lock striker can also be adjusted
both up and down and sideways, to
provide positive engagement with the lock
mechanism. This is done by loosening the
mounting bolts and moving the striker as
necessary (see illustration).
14 Boot lid/tailgate- removal,
refitting and adjustment
1
Boot lid
1Open the boot lid, and cover the edges of
the boot compartment with pads or cloths to
protect the painted surfaces when the lid is
removed.
2Disconnect any cables or electrical
connectors attached to the boot lid that would
interfere with removal.
3Make alignment marks around the hinge
bolts (see illustration).
4Have an assistant support the lid, then
remove the lid-to-hinge bolts on both sides
and lift it off.
11•6 Bodywork and fittings
13.7 The door lock striker position can be
adjusted after loosening the screws
(arrowed)13.5 Remove the nuts (arrowed) and
detach the door from the hinges
13.4 Detach the circlip (arrowed) from the
tapered end of the pin12.3 On models without electric windows,
prise off the window regulator handle trim
piece for access to the retaining screw

5Refitting is the reverse of removal. Align the
lid-to-hinge bolts with the marks made during
removal.
6After refitting, close the lid and make sure
it’s in proper alignment with the surrounding
panels. Fore-and-aft and side-to-side
adjustments are controlled by the position of
the hinge bolts in the slots. To make an
adjustment, loosen the hinge bolts, reposition
the lid, and retighten the bolts.
7The height of the lid in relation to the
surrounding body panels when closed can be
changed by loosening the lock and/or striker
bolts, repositioning the striker and/or lock,
and tightening the bolts (see illustrations).
Caution: If the radio in your
vehicle is equipped with an anti-
theft system, make sure you have
the correct activation code
before disconnecting the battery, Refer to
the information on page 0-7 at the front of
this manual before detaching the cable.
Note: If, after connecting the battery, the
wrong language appears on the instrument
panel display, refer to page 0-7 for the
language resetting procedure.
Tailgate
8Disconnect the battery negative cable.
9Open the tailgate and cover the rear edge
of the roof with pads or cloths to protect the
painted surfaces when the tailgate isremoved. On 5-Series models, the window
may be removed separately by disconnecting
the wiring and unscrewing the mounting
screws - have an assistant hold the window
while the screws are being loosened (see
illustration).
10Remove the trim from the inside of the
tailgate. Also where necessary on 5-Series
models, remove the edge covers for access to
the strut mountings.
11Disconnect the wiring loom and the
washer tubing. On some models, it will be
necessary to pull the wiring loom out of the
rear pillar and then disconnect the plug (see
illustration).
12While an assistant holds the tailgate open,disconnect the struts on both sides by
unscrewing the mounting screws. Where
applicable, pull out the retaining pin or spring
clip, and remove the strut from the ball (see
illustrations).
13Mark the position of the hinge arms on the
tailgate with a pencil.
14Unscrew the bolts and withdraw the
tailgate from the hinge arms. On 5-Series
models, it will be necessary to use an Allen
key or bit (see illustration).
15Refitting is the reverse of removal, but
make sure that the previously-made marks
are correctly aligned. Check that the tailgate
closes centrally between the rear pillars and
enters the lock correctly.
Bodywork and fittings 11•7
14.7b Adjust the boot lid lock striker after
loosening the bolts (arrowed)14.7a Loosen the lock bolts (arrowed) and
move the lock to adjust the boot lid closing
position14.3 Mark around the hinge bolts so you
can refit the boot lid in its original location
- unscrew or loosen the boot lid-to-hinge
bolts to remove or adjust it
14.12c Removing the retaining pin to
disconnect the bottom of the tailgate
support strut (5-Series)14.12b Strut mounting on the tailgate
(5-Series)14.12a Removing the tailgate strut spring
clip (3-Series)
14.11 Removing the wiring from the rear
pillar (5-Series)14.9 Tailgate window mounting screws
(5-Series)
11

12
Chapter 12 Body electrical systems
Bulb renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Central locking system - description and check . . . . . . . . . . . . . . . . 20
Cruise control system - description and check . . . . . . . . . . . . . . . . 19
Direction indicator/hazard warning flasher - check and renewal . . . 5
Electric windows - description and check . . . . . . . . . . . . . . . . . . . . 21
Electrical system fault finding - general information . . . . . . . . . . . . . 2
Fuses - general information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
General information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Headlight housing - removal and refitting . . . . . . . . . . . . . . . . . . . . . 14
Headlights - adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Headlights - bulb renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12Heated rear window - check and repair . . . . . . . . . . . . . . . . . . . . . . 17
Ignition switch - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . 7
Instrument cluster - removal and refitting . . . . . . . . . . . . . . . . . . . . . 10
Radio - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Radio aerial - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Relays - general information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Service Indicator (SI) board - general information . . . . . . . . . . . . . . 11
Steering column switches - removal and refitting . . . . . . . . . . . . . . . 6
Supplemental Restraint System (SRS) - general information . . . . . . 18
Windscreen/tailgate wiper motor - removal and refitting . . . . . . . . . 16
Wiring diagrams - general information . . . . . . . . . . . . . . . . . . . . . . . 22
12•1
Easy,suitable for
novice with little
experienceFairly easy,suitable
for beginner with
some experienceFairly difficult,
suitable for competent
DIY mechanic
Difficult,suitable for
experienced DIY
mechanicVery difficult,
suitable for expert
DIY or professional
Degrees of difficulty Contents
1 General information
The chassis electrical system of this vehicle
is of 12-volt, negative earth type. Power for
the lights and all electrical accessories is
supplied by a lead/acid-type battery, which is
charged by the alternator.
This Chapter covers repair and service
procedures for various chassis (non-engine
related) electrical components. For
information regarding the engine electrical
system components (battery, alternator,
distributor and starter motor), see Chapter 5.
Warning: To prevent electrical
short-circuits, fires and injury,
always disconnect the battery
negative terminal before
checking, repairing or renewing electrical
components.
Caution: If the radio in your
vehicle is equipped with an anti-
theft system, make sure you have
the correct activation code
before disconnecting the battery, Refer to
the information on page 0-7 at the front of
this manual before detaching the cable.
Note: If, after connecting the battery, the
wrong language appears on the instrument
panel display, refer to page 0-7 for the
language resetting procedure.
2 Electrical system fault
finding- general information
2
A typical electrical circuit consists of an
electrical component, any switches, relays,
motors, fuses, fusible links or circuit breakers,
etc related to that component, and the wiring
and connectors that link the components to
both the battery and the chassis. To help you
pinpoint an electrical circuit problem, wiring
diagrams are included at the end of this book.
Before tackling any troublesome electrical
circuit, first study the appropriate wiring
diagrams to get a complete understanding of
what makes up that individual circuit.
Troublespots, for instance, can often be
isolated by noting if other components related
to that circuit are routed through the same
fuse and earth connections.
Electrical problems usually stem from
simple causes such as loose or corroded
connectors, a blown fuse, a melted fusible
link, or a bad relay. Inspect all fuses, wires
and connectors in a problem circuit first.
The basic tools needed include a circuit
tester, a high-impedance digital voltmeter, a
continuity tester and a jumper wire with an in-
line circuit breaker for bypassing electrical
components. Before attempting to locate or
define a problem with electrical testinstruments, use the wiring diagrams to
decide where to make the necessary
connections.
Voltage checks
Perform a voltage check first when a circuit
is not functioning properly. Connect one lead
of a circuit tester to either the negative battery
terminal or a known good earth.
Connect the other lead to a connector in
the circuit being tested, preferably nearest to
the battery or fuse. If the bulb of the tester
lights up, voltage is present, which means that
the part of the circuit between the connector
and the battery is problem-free. Continue
checking the rest of the circuit in the same
fashion.
When you reach a point at which no voltage
is present, the problem lies between that point
and the last test point with voltage. Most of
the time, problems can be traced to a loose
connection.Note:Keep in mind that some
circuits receive voltage only when the ignition
key is turned to a certain position.
Electrical fault diagnosis is simple if you
keep in mind that all electrical circuits are
basically electricity running from the battery,
through the wires, switches, relays, fuses and
fusible links to each electrical component
(light bulb, motor, etc) and then to earth, from
where it is passed back to the battery. Any
electrical problem is an interruption in the flow
of electricity to and from the battery.

indicates that the direction indicator and/or
hazard fuse has blown, check the wiring for a
short-circuit before fitting a new fuse.
4Make sure that the new unit is identical to
the original. Compare the old one to the new
one before fitting it.
5Refitting is the reverse of removal.
6 Steering column switches-
removal and refitting
1
Warning: Some later models are
equipped with an airbag or
Supplemental Restraint System
(SRS). To avoid possible damage
to this system, the manufacturer
recommends that, on airbag-equipped
models, the following procedure should be
left to a dealer service department, or
other specialist, because of the special
tools and techniques required. There is a
risk of injury if the airbag is accidentally
triggered.
Caution: If the radio in your
vehicle is equipped with an anti-
theft system, make sure you have
the correct activation code
before disconnecting the battery, Refer to
the information on page 0-7 at the front of
this manual before detaching the cable.
Note: If, after connecting the battery, the
wrong language appears on the instrument
panel display, refer to page 0-7 for the
language resetting procedure.
1Disconnect the battery negative cable,
remove the steering wheel (see Chapter 10)
and steering column shrouds (see Chapter 11).
Direction indicator/headlight
switch
2Where necessary, remove the switch
mounting screws. Depress the tabs and pull
the switch out of the steering column
mounting (see illustration).
3Trace the switch wires down the steering
column to the electrical connector, and
unplug them (see illustration).
4Refitting is the reverse of removal.
Wiper/washer switch
5Where necessary, remove the switch
mounting screws.
6Depress the release clip, and detach the
switch from the steering column mounting
(see illustration). Trace the switch wiring
down the steering column to the electrical
connector, and unplug it.
7Refitting is the reverse of removal.
Cruise control switch
8Remove the wiper/washer switch.
9Where necessary, remove the switch
mounting screw. Squeeze the release tabs,
and withdraw the switch from the mounting
(see illustration).
10Disconnect the switch electrical
connector from the harness at the base of the
steering column.
11Refitting is the reverse of removal.
7 Ignition switch-
removal and refitting
1
Warning: Some later models are
equipped with an airbag or
Supplemental Restraint System
(SRS). To avoid possible damage
to this system, the manufacturer
recommends that, on airbag-equipped
models, the following procedure should be
left to a dealer service department, or
other specialist, because of the specialtools and techniques required. There is a
risk of injury if the airbag is accidentally
triggered.
Caution: If the radio in your
vehicle is equipped with an anti-
theft system, make sure you have
the correct activation code
before disconnecting the battery, Refer to
the information on page 0-7 at the front of
this manual before detaching the cable.
Note: If, after connecting the battery, the
wrong language appears on the instrument
panel display, refer to page 0-7 for the
language resetting procedure.
Removal
1Disconnect the battery negative cable.
2Remove the steering wheel (see Chap-
ter 10).
3Remove the steering column shrouds (see
Chapter 11).
4Where necessary, remove the direction
indicator/headlight control switch (see Sec-
tion 6).
5Detach the clips by inserting a small
screwdriver into the openings on the sides
while pulling out on the switch (see
illustration).
6Unplug the electrical connector from the
harness at the base of the steering column,
and remove the switch.
Refitting
7Refitting is the reverse of removal.
Body electrical systems 12•3
6.3 Follow the wiring down the steering
column to the connector6.2 Squeeze the tabs to release the switch
from the mounting
6.9 Cruise control switch removal6.6 Squeeze the wiper/washer switch tabs
and pull it directly out of the mounting
12
5.1 The direction indicator/hazard warning
flasher unit is located on the steering
column on most models - squeeze the
tabs to detach it

8 Radio- removal and refitting
1
Caution: If the radio in your
vehicle is equipped with an anti-
theft system, make sure you have
the correct activation code
before disconnecting the battery, Refer to
the information on page 0-7 at the front of
this manual before detaching the cable.
Note: If, after connecting the battery, the
wrong language appears on the instrument
panel display, refer to page 0-7 for the
language resetting procedure.
Removal
1Disconnect the battery negative cable.
2The radios on most models are held in place
by internal clips which are usually located at
the sides or corners of the unit faceplate.
Removal requires a special tool which is
inserted into the holes to release the clips so
the radio can be pulled out. These tools can be
fabricated from heavy wire, or are available
from your dealer or a car audio specialist. On
anti-theft radios, the clips are moved in and
out by internal screws which require another
type of tool. Insert the tool into the holes until
the clips release, then withdraw the radio from
the dash panel. Disconnect the wiring from the
radio and remove it.3On some models, the radio is held in place
by screws located beneath the faceplate. The
control knobs must be pulled off before the
faceplate can be withdrawn.
Refitting
4Refitting is the reverse of removal.
9 Aerial- removal and refitting
1
Caution: If the radio in your
vehicle is equipped with an anti-
theft system, make sure you have
the correct activation code
before disconnecting the battery, Refer to
the information on page 0-7 at the front of
this manual before detaching the cable.
Note: If, after connecting the battery, the
wrong language appears on the instrument
panel display, refer to page 0-7 for the
language resetting procedure.
Removal
1Disconnect the battery negative cable.
2Use circlip pliers to unscrew the aerial
mounting nut.
3Open the boot lid/tailgate and remove the
left side trim panel. On some models, the jack
and tail light cluster cover will have to be
removed first.
4Unplug the aerial power and radio lead
connectors (as applicable), remove the
retaining bolts, and remove the aerial and
motor assembly.
Refitting
5Refitting is the reverse of removal.
10 Instrument cluster-
removal and refitting
2
Caution: The instrument cluster
and components are very
susceptible to damage from
static electricity. Make sure you
are earthed and have dischargedany static electricity (by touching an object
such as a metal water pipe) before
touching the cluster or components.
Caution: If the radio in your
vehicle is equipped with an anti-
theft system, make sure you have
the correct activation code
before disconnecting the battery, Refer to
the information on page 0-7 at the front of
this manual before detaching the cable.
Note: If, after connecting the battery, the
wrong language appears on the instrument
panel display, refer to page 0-7 for the
language resetting procedure.
Removal
1Disconnect the battery negative cable.
2As necessary, remove the steering column
shrouds and lower trim panel (see Chap-
ter 11).
3Remove the screws holding the cluster to
the facia (see illustration). Note the location
of the lower screws to ensure they are refitted
in the same place. On 3-Series models, the
length of the two lower inner screws must not
exceed 9.5 mm.
4Tilt the top of the cluster back, reach
behind it and detach the electrical connectors
by pressing on the levers, then lift the cluster
out of the facia opening (see illustration).
5For access to the cluster components,
release the catches or remove the screws,
and separate the two halves (see
illustration).
Refitting
6Refitting is the reverse of removal.
11 Service Indicator (SI) board-
general information
All models that have service indicator lights
are equipped with a Service Indicator (SI)
board located in the instrument cluster. This
board turns the lights on at the proper mileage
intervals. The lights can only be turned off
using a special tool which plugs into the
engine check connector (see Chapter 1). The
12•4 Body electrical systems
10.5 Turn the plastic knobs to release the
back of the cluster (some models use
screws)10.4 Push on the levers to detach the
cluster electrical connectors10.3 Use a Phillips screwdriver to remove
the instrument cluster retaining screws
7.5 Insert a screwdriver into the openings
(arrowed) on each side of the switch to
release the clip while pulling out

13 Headlights- adjustment
2
Note:The headlights must be aimed correctly.
If adjusted incorrectly, they could momentarily
blind the driver of an oncoming vehicle and
cause a serious accident, or seriously reduce
your ability to see the road. The headlights
should be checked for proper aim every
12 months (as is done during the MOT test),
and any time a new headlight is fitted or front-
end body work is performed. It should be
emphasised that the following procedure will
only provide a temporary setting until the
headlights can be adjusted by a properly-
equipped garage.
1Each headlight has two adjusting screws,
one controlling up-and-down movement and
one controlling left-and-right movement (see
illustration). It may be necessary to remove
the grille (see Chapter 11) for access to these
screws.
2There are several methods of adjusting the
headlights. The simplest method requires a
blank wall (or garage door) 25 feet in front of
the vehicle, and a level floor.
3Position masking tape vertically on the wall,
to mark the vehicle centreline and the
centreline of both headlights. Note:It may be
easier to position the tape on the wall with the
vehicle parked only a few inches away, and
then move the vehicle back the required
distance when all marks have been made.
4Make a horizontal line on the wall to mark
the centreline of all headlights.
5Move the vehicle back so that it is 25 feet
away from the marked wall (keep the front end
of the vehicle square to the wall). Adjustment
should be made with the vehicle sitting level,
the fuel tank half-full, and with no unusually
heavy loads in the vehicle.
6Switch on the dipped beam. The bright
spots on the wall should be two inches below
the horizontal line, and two inches to the left
of the headlight vertical lines. Adjustment is
made by turning the adjusting screw to raise
or lower the beam. The other adjusting screwshould be used in the same manner to move
the beam left or right.
7With main beam on, the bright spots on the
wall should be exactly on the vertical lines,
and just below the horizontal line. Note:It may
not be possible to position the headlight aim
exactly for both main and dipped beams. If a
compromise must be made, keep in mind that
the dipped beam is most used, and will have
the greatest effect on driver safety.
8Have the headlights adjusted by a dealer
service department or qualified garage at the
earliest opportunity.
14 Headlight housing-
removal and refitting
1
Caution: If the radio in your
vehicle is equipped with an anti-
theft system, make sure you have
the correct activation code
before disconnecting the battery, Refer to
the information on page 0-7 at the front of
this manual before detaching the cable.
Note: If, after connecting the battery, the
wrong language appears on the instrument
panel display, refer to page 0-7 for the
language resetting procedure.
Removal
1Disconnect the battery negative cable.2Remove the side grille (see Chapter 11),
then remove the rear cover(s) where
necessary.
3Unplug the headlight (sealed beam-type) or
remove the bulb (halogen bulb-type).
4Remove the screws and detach the housing
(see illustration).
Refitting
5Refitting is the reverse of removal.
15 Bulb renewal
1
1The lenses of many lights are held in place
by screws, which makes it a simple procedure
to gain access to the bulbs.
2On some lights, the lenses are held in place
by clips. The lenses can be removed by using
a small screwdriver to prise them off.
3Several bulbs are mounted in self-earthing
holders, and are removed by pushing in and
turning them anti-clockwise (see illustration).
The bulbs can then be removed (see
illustrations).
4The tail lights on 3-Series models are
accessible after removing the housing, then
removing the bulbs (see illustrations).
5To gain access to the facia lights, the
instrument cluster will have to be removed
first (see illustration).
12•6 Body electrical systems
15.3c . . . then pull the bulb from the
holder15.3b On models with high-mounted
centre brake lights, the self-earthing
holder is accessible from the luggage area
- pull the holder out . . .15.3a The tail light bulbs on later 5-Series
models are in self-earthing holders which
can be simply pulled out of the housing -
the bulb is then removed from the holder
14.4 Remove the screws (arrowed) and
detach the headlight housing13.1 The headlight adjustment screws
(arrowed) are accessible from the back of
the headlight on 3-Series models

12Refitting is a reversal of removal. When
fitting the motor, if necessary plug in the
connector and run the motor briefly until it is
in the “neutral” (wiper parked) position.
17 Heated rear window-
check and repair
2
1The heated rear window consists of a
number of horizontal elements on the glass
surface.
2Small breaks in the element can be repaired
without removing the rear window.
Check
3Switch on the ignition and the heated rear
window.
4Place the positive lead of a voltmeter to the
heater element nearest to the incoming power
source.
5Wrap a piece of aluminium foil around the
negative lead of the voltmeter on the positive
side of the suspected broken element, and
slide it slowly towards the negative side.
Watch the voltmeter needle - when it moves
from zero, you have located the break.
Repair
6Repair the break in the line using a repair kit
recommended specifically for this purpose,
such as BMW repair kit No. 81 22 9 (or
equivalent). Included in this kit is plastic
conductive epoxy. The following paragraphs
give general instructions for this type of repair;
follow the instructions supplied with the repair
kit if they are different.
7Prior to repairing a break, switch off the
circuit and allow it to cool down for a few
minutes.
8Lightly buff the element area with fine steel
wool, then clean it thoroughly.
9Use masking tape to mask off the area of
repair, leaving a slit to which the epoxy can be
applied.
10Mix the epoxy thoroughly, according to
the instructions on the package.
11Apply the epoxy material to the slit in the
masking tape, overlapping the undamaged
area about 20 mm on each end.12Allow the repair to cure for 24 hours
before removing the tape and using the
heated rear window.
18 Supplemental Restraint
System (SRS)- general
information
Later models are equipped with a
Supplemental Restraint System (SRS),
incorporating an airbag. This system is
designed to protect the driver from serious
injury in the event of a head-on or frontal
collision. It consists of an airbag module in the
centre of the steering wheel, two crash
sensors mounted on the front inner wing
panels, and a crash safety switch located
inside the passenger compartment.
The airbag module contains a housing
incorporating the airbag and the inflator units.
The inflator assembly is mounted on the back
of the housing over a hole through which gas
is expelled, inflating the bag almost instanta-
neously when an electrical signal is sent from
the system. This signal is carried by a wire
which is specially wound with several turns,
so the signal will be transmitted regardless of
the steering wheel position.
The SRS system has three sensors: two at
the front, mounted on the inner wing panels
(see illustration), and a safety switch located
inside the passenger compartment. The crash
sensors are basically pressure-sensitive
switches, which complete an electrical circuit
during an impact of sufficient force. The
electrical signal from the crash sensors is sent
to a third sensor, which then completes the
circuit and inflates the airbag.
The module containing the safety switch
monitors the system operation. It checks the
system every time the vehicle is started,
causing the AIRBAG warning light to come on,
then go out if the system is operating
correctly. If there is a fault in the system, the
light will stay on. If the AIRBAG warning light
does stay on, or if it comes on while driving,
take the vehicle to your dealer immediately.
19 Cruise control system-
description and check
1
The cruise control system maintains vehicle
speed using a vacuum-actuated servo motor
located in the engine compartment, which is
connected to the throttle linkage by a cable.
The system consists of the servo motor,
clutch switch, brake switch, control switches,
a relay, and associated vacuum hoses.
Because of the complexity of the cruise
control system, repair should be left to a
dealer service department. However, it is
possible for the home mechanic to make
simple checks of the wiring and vacuum
connections for minor faults which can be
easily repaired. These include:
a) Inspect the cruise control actuating switches
for broken wires and loose connections.
b) Check the cruise control fuse.
c) The cruise control system is operated by
vacuum, so it’s critical that all vacuum
switches, hoses and connections are
secure. Check the hoses in the engine
compartment for loose connections,
cracks, or obvious vacuum leaks.
20 Central locking system-
description and check
2
The central door locking system operates
the door lock actuators mounted in each
door. The system consists of the switches,
actuators and associated wiring. Diagnosis is
limited to simple checks of the wiring
connections and actuators for minor faults
which can be easily repaired. These include:
a) Check the system fuse and/or circuit
breaker (where applicable).
b) Check the switch wires for damage and
loose connections. Check the switches
for continuity.
c) Remove the door trim panel(s), and check
the actuator wiring connections to see if
they’re loose or damaged. Inspect the
actuator rods to make sure they aren’t
12•8 Body electrical systems
18.3 The SRS system crash sensors
(arrowed) are located in the engine
compartment - check the wiring regularly
for damage16.11b Tailgate wiper motor (5-Series)16.11c Wiper blade and pivot mechanism
on the rear window (5-Series)

BK Black
BL Blue
BR BrownGE Yellow
GN Green
GR Green or GreyGY Grey
OR Orange
PK PinkR Red
RS Pink
RT RedSW Black
TN Tan
V VioletVI Violet
W WhiteWS White
Y Yellow
Body electrical systems 12•9
12
Colour codes bent or damaged. The actuator can be
checked by applying battery power
momentarily. A discernible click indicates
that the solenoid is operating properly.
21 Electric window system-
description and check
2
The electric window system operates the
electric motors mounted in the doors which
lower and raise the windows. The system
consists of the control switches, the motors,
window mechanisms (regulators) andassociated wiring. Removal of the motors and
regulators is described in Chapter 11.
Diagnosis is usually limited to simple
checks of the wiring connections and motors
for minor faults which can be easily repaired.
These include:
a) Check the electric window switches for
broken wires and loose connections.
b) Check the electric window fuse/and or
circuit breaker (where applicable).
c) Remove the door trim panel(s) and check
the electric window motor wires to see if
they’re loose or damaged. Inspect the
window mechanisms for damage which
could cause binding.
22 Wiring diagrams-
general information
Since it isn’t possible to include all wiring
diagrams for every model year covered by this
manual, the following diagrams are those that
are typical and most commonly needed.
Prior to checking any circuit, check the
fuses and circuit breakers to make sure they’re
in good condition. Make sure the battery is
fully charged and check the cable connections
(see Chapter 1). Make sure all connectors are
clean, with no broken or loose terminals.